Hawaii Research: Projects, Research Publications, Presentations, Thesis and Dissertations, Technical Publications

Hawaii Research Activities

Unit student, Ricky Tabandera, throws a cast net to sample nekton at Waiahole Fishpond, Hawaii Island.

Research conducted under the auspices of the HCFRU addresses the needs of the state of Hawai’i, the Pacific Islands region, and the nation. Specific fields of interest include, but are not limited to: fisheries biology, ecology, and management; aquatic and marine ecology; community ecology; fisheries oceanography; ecophysiology; behavioral ecology; reproductive biology; conservation biology; human dimensions of fisheries; fisheries economics; fish culture; and the response of fisheries resources and freshwater, estuarine, and marine ecosystems to climate change. These research efforts are based on the technical expertise of Unit scientists and university cooperators.

Projects

Project	Completion Date
Exploring the early life history and habitat connectivity of paku‘iku‘i (Acanthurus achilles) around Hawai‘i Island	September 2024	This project will provide crucial insight into the basic biology of a culturally important food fish in Hawai‘i, the paku‘iku‘i or Achilles tang (<i>Acanthurus achilles</i>), whose numbers have recently and mysteriously declined in west Hawai‘i Island. Project scientists will work directly with State resource managers to plan and implement monitoring of fish larvae, recruits, and juveniles, which are critical stages that may contribute to the decline and rebound of this fish’s population. The proposed work will thus inform the State’s adaptive management plan for this species in west Hawai‘i within the first two years of the fishery’s closure.	In Hawai‘i, hundreds of species are caught in commercial and non-commercial reef fisheries, but we know relatively little about the biology of most of these species and their responses to exploitation. One such species is paku‘iku‘i, also known as the Achilles tang (<i>Acanthurus achilles</i>), whose numbers have recently and mysteriously declined in west Hawai‘i Island. The state resource management agency exercised its adaptive management rulemaking authority in December 2022 to place a 2-year moratorium on all commercial and non-commercial take of paku‘iku‘i in west Hawai‘i Island so that the basic biology and cause of the collapse of this fish’s population can be explored. One significant knowledge gap in this species’ biology that may play an important role in shaping the past and future trajectory of its population is its early life history. Therefore, the funded work will investigate the larval distribution, recruitment dynamics, and relative connectivity of juvenile and adult habitats of paku‘iku‘i. SCUBA surveys in east Hawai‘i Island – where paku‘iku‘i are more abundant than west Hawai‘i Island – will explore habitat requirements and behaviors of new recruits and juveniles across a depth gradient and adjacent to shallow, adult habitat. In addition, targeted light traps and plankton tows will be used to understand the distribution of larval surgeonfishes (Acanthuridae) and paku‘iku‘i. This study’s results will directly inform the State’s adaptive management plan for this species, which will need to be reviewed in two years, and will support a structural decision-making model that is in development by Cooperative Research Units staff and State resource managers.
Analysis and Review of Fishery-Dependent Data for Hawaiian Nearshore Noncommercial Fisheries	December 2023	The State of Hawai‘i’s Division of Aquatic Resources (DAR) routinely collects survey data to monitor both the catch and effort of nearshore non-commercial fisheries. These data serve as the basis for justifying management actions and regulatory decisions taken by the agency and by the State government, but the data are plagued by an optimization problem of maximizing the ability to detect meaningful changes while minimizing the financial and opportunity costs of collecting sufficient data to do so. The HCFRU was asked by DAR to assess their non-commercial, creel survey dataset to determine 1) whether catch and effort can be estimated from the existing data, 2) whether data were of sufficient quality to be used in data-limited stock assessments or other alternative approaches, 3) if correction factors could be developed to account for sources of bias, and 4) to review new approaches or technologies that could be deployed to more efficiently collect the data necessary to generate fishing catch and effort estimates. The results of this project will inform the State's ability to use the data as it presently exists, and make recommendations about ways to improve the collection and analysis of these data in the future, thus improving the State's ability to more effectively manage non-commercial fisheries.	The State of Hawai‘i’s Division of Aquatic Resources (DAR) routinely collects survey data to monitor both the catch and effort of nearshore non-commercial fisheries. These data serve as the basis for justifying management actions and regulatory decisions taken by the agency and by the State government, but the data are plagued by an optimization problem of maximizing the ability to detect meaningful changes while minimizing the financial and opportunity costs of collecting sufficient data to do so. The HCFRU was asked by DAR to assess their non-commercial, creel survey dataset to determine 1) whether catch and effort can be estimated from the existing data, 2) whether data were of sufficient quality to be used in data-limited stock assessments or other alternative approaches, 3) if correction factors could be developed to account for sources of bias, and 4) to review new approaches or technologies that could be deployed to more efficiently collect the data necessary to generate fishing catch and effort estimates. The results of this project will inform the State's ability to use the data as it presently exists, and make recommendations about ways to improve the collection and analysis of these data in the future, thus improving the State's ability to more effectively manage non-commercial fisheries.
Water Quality Thresholds to Improve Coral Restoration Outcomes and Ridge-to-Reef Management at Olowalu Reef, Maui	January 2026	Successful reef restoration requires detailed, site-specific information on the tolerances of local reef builders to prevailing environmental threats. Across Hawai‘i – and especially in southwest Maui – sedimentation is a major threat to coral-reef health. Proposed and ongoing watershed management projects focus on erosion reduction, but lack thresholds for sediment pollution and specific, measurable targets for upland sediment reduction. To address this need, the project PIs will work with local organizations and agencies to develop place- and species-specific thresholds of sediment stress to inform both makai (coral outplanting) and mauka (land-management) restoration efforts at Olowalu Reef, a critically important site in the region that is poised to receive millions of dollars for restoration and infrastructure improvements. The PIs and their partners are co-developing the project, the results of which will directly contribute to reef conservation and restoration success. Specifically, the proposed work will produce a map of the predicted success of coral restoration outplants across a sedimentation gradient at Olowalu and generate detailed sediment thresholds for local reef builders that can serve as targets for sediment reduction efforts. Importantly, the proposed approach can be replicated in other locations where establishing water quality targets for coral restoration is a critical management need.	Successful reef restoration requires detailed, site-specific information on the tolerances of local reef builders to prevailing environmental threats. Across Hawai‘i – and especially in southwest Maui – sedimentation is a major threat to coral-reef health. Proposed and ongoing watershed management projects focus on erosion reduction, but lack thresholds for sediment pollution and specific, measurable targets for upland sediment reduction. To address this need, the project PIs will work with local organizations and agencies to develop place- and species-specific thresholds of sediment stress to inform both makai (coral outplanting) and mauka (land-management) restoration efforts at Olowalu Reef, a critically important site in the region that is poised to receive millions of dollars for restoration and infrastructure improvements. The PIs and their partners are co-developing the project, the results of which will directly contribute to reef conservation and restoration success. Specifically, the proposed work will produce a map of the predicted success of coral restoration outplants across a sedimentation gradient at Olowalu and generate detailed sediment thresholds for local reef builders that can serve as targets for sediment reduction efforts. Importantly, the proposed approach can be replicated in other locations where establishing water quality targets for coral restoration is a critical management need.
Impact of extreme events on native and nonnative fauna on Hawaii stream ecosystem	November 2020	Freshwater is a critical driver for island ecosystems. Climate change has fundamentally altered the water cycle in these tropical islands. The changes in dynamic patterns of streamflow could result in the temporal and spatial difference in the fluvial, estuarine, and coastal habitats. In particular, these habitats support the nine native aquatic species in Hawaii at different stages of their amphidromous life cycle. To examine how changes in streamflow regime has impacted habitat quality for native migratory aquatic species, an ongoing project has examined statewide long-term stream records. We are in the process of building hydrological models and connecting the stream dynamics with existing biological data to address the climate impact on stream habitats. In this study we will examine the historical daily flow and rainfall records to describe the hydrological patterns of stream habitats in Hawaii and we will empirically evaluate the swimming performance of various non-native species in order to better predict the effect of extreme high flow events on non-native fish populations in various stream reaches. With similar concept, we will connect with like-minded researchers in Puerto Rico to explore and develop a comparative study to address the changing aquatic ecosystems due to the extreme flood. This research project has arisen explicitly from existing research and discussions with local stakeholders (e.g., Commission on Water Resource Management, Hawaii Fish Habitat Partnership, National Fish Habitat Partnership, Pacific Island Fisheries and Wildlife Services) and researchers from different regions. Intermediate results will be presented to stakeholders to determine the most useful format for final dissemination to user groups.	Freshwater is a critical driver for island ecosystems. Climate change has fundamentally altered the water cycle in these tropical islands. The changes in dynamic patterns of streamflow could result in the temporal and spatial difference in the fluvial, estuarine, and coastal habitats. In particular, these habitats support the nine native aquatic species in Hawaii at different stages of their amphidromous life cycle. To examine how changes in streamflow regime has impacted habitat quality for native migratory aquatic species, an ongoing project has examined statewide long-term stream records. We are in the process of building hydrological models and connecting the stream dynamics with existing biological data to address the climate impact on stream habitats. In this study we will examine the historical daily flow and rainfall records to describe the hydrological patterns of stream habitats in Hawaii and we will empirically evaluate the swimming performance of various non-native species in order to better predict the effect of extreme high flow events on non-native fish populations in various stream reaches. With similar concept, we will connect with like-minded researchers in Puerto Rico to explore and develop a comparative study to address the changing aquatic ecosystems due to the extreme flood. This research project has arisen explicitly from existing research and discussions with local stakeholders (e.g., Commission on Water Resource Management, Hawaii Fish Habitat Partnership, National Fish Habitat Partnership, Pacific Island Fisheries and Wildlife Services) and researchers from different regions. Intermediate results will be presented to stakeholders to determine the most useful format for final dissemination to user groups.
How will changing reefscapes affect the prevalence of ciguatera on Hawaiian reefs?	August 2022	Ciguatera fish poisoning (CFP) is caused by consumption of reef fishes containing toxins produced by epiphytic dinoflagellates in the genus <i>Gambierdiscus</i>. Anthropogenic climate change and alteration of reef fish assemblages have the potential to increase the abundance and range of <i>Gambierdiscus</i> spp. However, it is not clear how the resulting changes to reef ecosystems may interact to influence the prevalence of ciguatoxic fishes and thus the risk of CFP posed to local communities dependent upon these fisheries. Therefore, the overall goal of the proposed study is to begin to disentangle the complex relationship between the effects of anthropogenic climate change, fishing pressure on herbivorous reef fishes, and the prevalence of ciguatoxic fishes. Therefore, the primary objective of this proposed study is to assess the prevalence of ciguatoxins in reef fishes along a disturbance gradient created by a major coral bleaching event that spans sites inside and outside areas protected from fishing pressure along the west coast of Hawai‘i Island. Secondarily, the degree of temporal stability or seasonality in the prevalence of ciguatoxins in reef fishes over the course of the proposed study will be assessed to the extent possible under the proposed sampling regime.	Cigtera fish poisoning (CFP) is caused by consumption of reef fishes containing toxins produced by epiphytic dinoflagellates in the genus <i>Gambierdiscus</i>. Anthropogenic climate change and alteration of reef fish assemblages have the potential to increase the abundance and range of <i>Gambierdiscus</i> spp. However, it is not clear how the resulting changes to reef ecosystems may interact to influence the prevalence of ciguatoxic fishes and thus the risk of CFP posed to local communities dependent upon these fisheries. Therefore, the overall goal of the proposed study is to begin to disentangle the complex relationship between the effects of anthropogenic climate change, fishing pressure on herbivorous reef fishes, and the prevalence of ciguatoxic fishes. Therefore, the primary objective of this proposed study is to assess the prevalence of ciguatoxins in reef fishes along a disturbance gradient created by a major coral bleaching event that spans sites inside and outside areas protected from fishing pressure along the west coast of Hawai‘i Island. Secondarily, the degree of temporal stability or seasonality in the prevalence of ciguatoxins in reef fishes over the course of the proposed study will be assessed to the extent possible under the proposed sampling regime. This project is being conducted in collaboration with Hawaii Division of Aquatic Resources, The Nature Conservancy, Kaupulehu Marine Life Advisory Council, and other community and stakeholder groups.
Estimating detection and occupancy coefficients for the Pacific Islands coral reef fish species	October 2020	Data-limited stock assessment models are used to determine the status of the coral reef fish species in the western Pacific. Estimates of standing stock biomass are based on an expansion of the species biomass density with known hard bottom substrate from 0-30m depth from underwater visual census surveys. The expansion to generate estimates of standing stock biomass includes implicit assumptions of uniform distribution and perfect detection. These assumptions are rarely met as variations in fish behavior, areas surveyed with varying fishing pressure, habitat type, diver survey experience affect the ability to detect species and individuals and have repercussions to the population estimators. Therefore, quantifying the detectability and occupancy coefficients of each coral reef fish species can refine the standing stock biomass estimates and reduce bias. The overall aim of this project is to analyze the National Marine Fisheries Service Coral Reef Ecosystem Program Reef Fish Dataset to estimate detection and occupancy coefficients for species listed in the Western Pacific Regional Fishery Management Council’s Fishery Ecosystem Plans to refine the standing stock biomass estimates used in stock assessment.	Data-limited stock assessment models are used to determine the status of the coral reef fish species in the western Pacific. Estimates of standing stock biomass are based on an expansion of the species biomass density with known hard bottom substrate from 0-30m depth from underwater visual census surveys. The expansion to generate estimates of standing stock biomass includes implicit assumptions of uniform distribution and perfect detection. These assumptions are rarely met as variations in fish behavior, areas surveyed with varying fishing pressure, habitat type, diver survey experience affect the ability to detect species and individuals and have repercussions to the population estimators. Therefore, quantifying the detectability and occupancy coefficients of each coral reef fish species can refine the standing stock biomass estimates and reduce bias. The overall aim of this project is to analyze the National Marine Fisheries Service Coral Reef Ecosystem Program Reef Fish Dataset to estimate detection and occupancy coefficients for species listed in the Western Pacific Regional Fishery Management Council’s Fishery Ecosystem Plans to refine the standing stock biomass estimates used in stock assessment.
Assessing fish habitat and population dynamics of fisheries resources at Kaloko Fishpond	September 2021	Throughout Hawaiʻi, fishponds are considered by their local communities as important cultural touchstones, a source of local, sustainably produced food, and an important component to the development of community-based management for nearshore fisheries. Within Kaloko Honokōhau National Historic Park (KAHO) the restoration of Kaloko Fishpond for traditional aquaculture management is an immediate goal of both the National Park Service (NPS) and an eager, dedicated community group. However, existing data on the demographics and condition of the fish populations within the pond, and the fish-habitat quality are poor to non-existent. Furthermore, the combination of gaps in traditional knowledge and Hawaiʻi’s significantly altered environmental conditions have made initiating sustainable fishpond management based on the traditional methods established prior to European contact challenging. Therefore, an understanding of the ecology of Kaloko Fishpond, particularly as it pertains to the population dynamics of its fish species, is critical to adapting traditional pond management practices to respond to already altered and continually changing environmental conditions. Grounding these practices in defensible science and traditional knowledge is necessary to move forward with the restoration and traditional management of Kaloko Fishpond.	Throughout Hawaiʻi, fishponds are considered by their local communities as important cultural touchstones, a source of local, sustainably produced food, and an important component to the development of community-based management for nearshore fisheries. Within Kaloko Honokōhau National Historic Park (KAHO) the restoration of Kaloko Fishpond for traditional aquaculture management is an immediate goal of both the National Park Service (NPS) and an eager, dedicated community group. However, existing data on the demographics and condition of the fish populations within the pond, and the fish-habitat quality are poor to non-existent. Furthermore, the combination of gaps in traditional knowledge and Hawaiʻi’s significantly altered environmental conditions have made initiating sustainable fishpond management based on the traditional methods established prior to European contact challenging. Therefore, an understanding of the ecology of Kaloko Fishpond, particularly as it pertains to the population dynamics of its fish species, is critical to adapting traditional pond management practices to respond to already altered and continually changing environmental conditions. Grounding these practices in defensible science and traditional knowledge is necessary to move forward with the restoration and traditional management of Kaloko Fishpond.
Assessing the functional equivalency of Hawaiian fishponds r...	May 2019	Hawaiian fishponds were important cultural and economic resources for native Hawaiians as they were an important component of a sophisticated, integrated food production system. Prior to European contact in 1778, an estimated 360-450 fishponds encompassing over 2,700 ha were in active production across the islands, contributing an estimated minimum annual yield in excess of 900,000 kg. However, changing demographics and systems of land ownership resulted in a decline in the use and upkeep of Hawaiian fishponds throughout the 19<sup>th</sup> Century. The cultural value of Hawaiian fishponds has not diminished and there has been a concerted effort from numerous community groups to restore fishponds in Hawaii since the early 1990s. Despite these efforts, only 21 ponds are currently in production with others in various stages of planning or restoration. However even in their various stages of disrepair, Hawaiian fishponds potentially may be an important component of the productivity of nearshore fisheries. The Hawaiian Islands have a relatively small amount of estuarine habitat, i.e., ≤ 200 km<sup>2</sup> depending on the definition of estuary used, relative to the amount of shoreline. Even though Hawaiian estuaries tend to be relatively small in size (1-2 km<sup>2</sup>) and unevenly distributed amongst the islands, they are productive for their size and represent critical nursery habitats for a number of species important to subsistence and recreational fisheries. Understanding the interaction between actively managed fishponds; inactive, abandoned, or otherwise unmanaged fishponds, and natural estuaries is important to better manage nearshore fisheries resources and monitor the distribution of coastal and marine invasive species, such as red mangrove <i>Rhizophora mangle</i> or the introduced mullet, Kanda <i>Osteomugil</i><i> engeli</i>. The goal of the proposed study is to evaluate the role of fishponds on the productivity of nearshore fisheries in Hawaii to inform permitting decisions and best management practices.	Hawaiian fishponds were important cultural and economic resources for native Hawaiians as they were an important component of a sophisticated, integrated food production system. Prior to European contact in 1778, an estimated 360-450 fishponds encompassing over 2,700 ha were in active production across the islands, contributing an estimated minimum annual yield in excess of 900,000 kg. However, changing demographics and systems of land ownership resulted in a decline in the use and upkeep of Hawaiian fishponds throughout the 19<sup>th</sup> Century. The cultural value of Hawaiian fishponds has not diminished and there has been a concerted effort from numerous community groups to restore fishponds in Hawaii since the early 1990s. Despite these efforts, only 21 ponds are currently in production with others in various stages of planning or restoration. However even in their various stages of disrepair, Hawaiian fishponds potentially may be an important component of the productivity of nearshore fisheries. The Hawaiian Islands have a relatively small amount of estuarine habitat, i.e., ≤ 200 km<sup>2</sup> depending on the definition of estuary used, relative to the amount of shoreline. Even though Hawaiian estuaries tend to be relatively small in size (1-2 km<sup>2</sup>) and unevenly distributed amongst the islands, they are productive for their size and represent critical nursery habitats for a number of species important to subsistence and recreational fisheries. Understanding the interaction between actively managed fishponds; inactive, abandoned, or otherwise unmanaged fishponds, and natural estuaries is important to better manage nearshore fisheries resources and monitor the distribution of coastal and marine invasive species, such as red mangrove <i>Rhizophora mangle</i> or the introduced mullet, Kanda <i>Osteomugil</i><i> engeli</i>. The goal of the proposed study is to evaluate the role of fishponds on the productivity of nearshore fisheries in Hawaii to inform permitting decisions and best management practices.
Towards a better understanding of Blue Suckers: validation of age determination methods & estimating the influence of temperature on aerobic scope & swimming performance	August 2019	This study will provide information on two critical aspects of the biology of Blue Sucker Cycleptus elongatus [state threatened] and Rio Grande Blue Sucker Cycleptus c.f. elongatus [SGCN] necessary for developing effective conservation and management plans for the species. First, the study will validate age estimation methods used for blue suckers throughout Texas and the rest of the United States and provide a means of assessing the accuracy and precision of age estimates. In addition, this study will use swim tunnel respirometry to evaluate the influence of temperature and dissolved oxygen on the swimming performance of blue suckers. This information will allow for an assessment of how stream discharges influence the fish' ability to migrate and utilize spawning habitat.	Blue suckers are listed as species of greatest conservation need or threatened by most states throughout their range. Proper management of these riverine, migratory species requires knowledge of their life-history, which is at present poorly understood. More specifically, knowledge of the association between cohort (year class) strength and hydrology is needed for proper instream flow recommendations. This study will provide data that addresses two critical needs: (1) validation of age estimation techniques, and (2) characterization of swimming performance under various environmental simulations. The project is a collaboration of researchers across multiple agencies and includes the USGS Texas and Hawaii Cooperative Fish and Wildlife Research Units, Texas Parks and Wildlife Department, and Texas Tech University. Validation of yearly annulus formation and evaluation of the accuracy of various structures used for aging blue suckers will provide a greater level of confidence in age estimates generated from wild-caught blue suckers. Assessments of swimming performance under various environmental conditions will improve habitat suitability models for blue suckers, particularly as they relate to discharge, current velocity, and temperature.

Research Publications

Research Publications	Publication Date
Wedding LM, CA Lepczyk, SJ Pittman, AM Friedlander, S Jorgensen. 2011. Quantifying seascape structure: extending terrestrial spatial pattern metrics to the marine realm. Mar. Ecol. Prog. Ser. 427:219-232.	April 2011
Suarez B & TB Grabowski. 2021. Estimating detection and occupancy coefficients for the Pacific Islands coral reef fish species. Hawaii Cooperative Fishery Research Unit Technical Report Series HCFRU-001. University of Hawaii at Hilo. Available online at: hdl.handle.net/10790/5553 \| Abstract \| Download \| Publisher Website	January 2021	The data-limited stock assessment models used to monitor the status of coral reef fish species in the Western Pacific region are dependent upon accurate estimates of standing stock biomass generated from underwater visual surveys of reefs. However, the imperfect detection of and variable occupancy of habitat by reef fishes are not currently accounted for in these estimates. Therefore, the objective of this project was to estimate detection and occupancy coefficients for the species listed in the Western Pacific Regional Fishery Management Council’s Fishery Ecosystem Plans by analyzing the Pacific Island Fishery Science Center-Coral Reef Ecosystem Program Reef Fish Dataset. These detection and occupancy coefficients would then be applied to refine standing stock biomass estimates. In general, species with higher detection probabilities and/or lower occupancy rates tended to exhibit the greatest differences in the estimates of standing stock biomass calculated with and without accounting for detection and occupancy. The standing stock biomass of most reef fish species seem to be underestimated when detection and occupancy are not accounted for. However, the standing stock biomass of larger-bodied targeted species, such as jacks, snappers, and groupers, seem to be over-estimated relative to the estimates generated when accounting for occupancy and detection. Based on the re-estimated standing stock biomass. While there are still issues to resolve regarding how well the current data collection methods meet the underlying assumptions of the detection and occupancy modeling approach, the inclusion of detection and occupancy coefficients seems likely to improve estimates of standing stock biomass of coral reef fish species.
Smith, L.W., D. Barshis, and C. Birkeland. 2007. Phenotypic plasticity for skeletal growth, density and calcification of Porites lobata in response to habitat type. Coral Reefs 26: 559-667.	April 2007
Smith, L.W, and C. Birkeland. 2007. .Effects of intermittent flow and irradiance level on back reef Porites corals corals at elevated seawater temperatures. Journal of Experimental Marine Biology and Ecology 341: 282-294	March 2007
Smith, L., H. Wirshing, A. C. Baker, C. Birkeland. Environmental versus genetic influences on growth rates of the corals Pocillopora eydouxi and Porites lobata. Pacific Science 62: 57-69.	January 2008
Sala E, Ballesteros E, Dendrinos P, Di Franco A, Ferretti F, Foley D, Fraschetti S, Friedlander A, and 19 others. 2012. The structure of Mediterranean rocky reef ecosystems across environmental and human gradients, and conservation implications. PLoS ONE 7(2): e32742. doi:10.1371/journal.pone.0032742	March 2012
Ruttenberg BI, Hamilton SL, Walsh SM, Donovan MK, Friedlander A, E DeMartini, E Sala, SA Sandin. 2011 Predator-induced demographic shifts in coral reef fish assemblages. PLoS ONE 6(6): e21062. doi:10.1371/journal.pone.0021062	June 2011
Roesler EL, & TB Grabowski. 2018. Estimating factors influencing the detection probability of semi-aquatic freshwater snails using quadrat survey methods. Hydrobiologia 808:153-161. doi: 10.1007/s10750-017-3415-9 \| Abstract	February 2018	Developing effective monitoring methods for elusive, rare, or patchily distributed species requires extra considerations, such as imperfect detection. Although detection is frequently modeled, the opportunity to assess it empirically is rare, particularly for imperiled species. We used Pecos assiminea (Assiminea pecos), an endangered semi-aquatic snail, as a case study to test detection and accuracy issues surrounding quadrat searches. Quadrats (9 x 20 cm; n = 12) were placed in suitable Pecos assiminea habitat and randomly assigned a treatment, defined as the number of empty snail shells (0, 3, 6, or 9). Ten observers rotated through each quadrat, conducting 5-minute visual searches for shells. The probability of detecting a shell when present was 67.4% ± 3.0, but decreased with increasing litter depth and fewer shells present. The mean (± SE) observer accuracy was 25.5% ± 4.3%. Accuracy was positively correlated to number of shells in the quadrat and negatively correlated to number of times a quadrat was searched. The results indicate quadrat surveys likely underrepresent true abundance, but accurately determine presence or absence. Understanding detection and accuracy of elusive, rare, or imperiled species improves density estimates and aids in monitoring and conservation efforts.
Raffaelli, D.G., Friedlander, A.M. 2012. Biodiversity and ecosystem functioning: an ecosystem-level approach. In Marine Biodiversity Futures and Ecosystem Functioning: frameworks, methodologies and integration (Paterson, D.M., Aspden, R.J., Solan, M., editors). Oxford Univ. Press. Pp 149-163.	July 2012
Pease JE, TB Grabowski, AP Pease, & PT Bean. 2018. Changing environmental gradients over forty years alter ecomorphological variation in Guadalupe Bass Micropterus treculii throughout a river basin. Ecology and Evolution 8:8508-8522. doi: 10.1002/ece3.4349. \| Abstract \| Publisher Website	July 2018	Understanding the degree of intraspecific variation within and among populations is a key aspect of predicting the capacity of a species to respond to anthropogenic disturbances. However, intraspecific variation is usually assessed at either limited temporal, but broad spatial scales or vice versa, which can make assessing changes in response to long-term disturbances challenging. We evaluated the relationship between the longitudinal gradient of changing flow regimes and land use/land cover patterns since 1980 and morphological variation of Guadalupe Bass Micropterus treculii throughout the Colorado River Basin of central Texas. The Colorado River Basin in Texas has experienced major alterations to the hydrologic regime due to changing land and water-use patterns. Historical collections of Guadalupe Bass prior to rapid human-induced change present the unique opportunity to study the response of populations to varying environmental conditions through space and time. Morphological differentiation of Guadalupe Bass associated with temporal changes in flow regimes and land use/land cover patterns suggests that they are exhibiting intraspecific trait variability, with contemporary individuals showing increased body depth, in response to environmental alteration through time (specifically related to an increase in herbaceous land cover, maximum flows, and the number of low pulses and high pulses). Additionally, individuals from tributaries with increased hydrologic alteration associated with urbanization or agricultural withdrawals tended to have a greater distance between the anal and caudal fin. These results reveal trait variation that may help to buffer populations under conditions of increased urbanization and sprawl, human population growth, and climate risk, all of which impose novel selective pressures, especially on endemic species like Guadalupe Bass. Our results contribute an understanding of the adaptability and capacity of an endemic population to respond to future changes expected based on demographic or climatic projection.
Pease JE, TB Grabowski, & AA Pease. 2017. Variation and plasticity and their interaction with urbanization in Guadalupe Bass populations on and off the Edwards Plateau. U.S. Department of Interior, Fish and Wildlife Service, Cooperator Science Series FWS/CSS-125-2017, Washington, D.C. \| Abstract \| Download	August 2017	The Colorado River Basin in Texas has experienced major alterations to its hydrologic regime due to changing land and water use patterns. These anthropogenic influences on hydrologic variability have had major implications for riparian and aquatic ecosystems and the species dependent upon them. However, impacts are often assessed at a limited temporal and spatial scale, tending to focus on relatively short and discrete periods or portions of a river basin. It is not clear how basin-wide alterations occurring over decades affect species. Guadalupe Bass Micropterus treculii are endemic to central Texas and are typically associated with shallow runs and riffles in small streams. However, Guadalupe Bass are found throughout the Colorado River Basin, including the mainstem portion of the lower river downstream of the city of Austin where they support a popular fishery. Because Guadalupe Bass exist across a wide range of stream orders within the basin, it is unclear whether populations respond similarly to anthropogenic disturbances or to conservation and restoration activities. Therefore, our objectives were to: 1. Assess the effects of urbanization and hydrology on the population structure and dynamics of Guadalupe Bass. 2. Evaluate the effects of environmental gradients on ecomorphological variation in Guadalupe Bass populations across multiple spatial scales. 3. Describe the life history, habitat use, and behavior of the Guadalupe Bass population in the lower Colorado River and compare it to populations in more “typical” habitats. Results contribute to an understanding of the response of Guadalupe Bass to anthropogenic disturbances, including increased urbanization in central Texas and further assist in the conservation of the species. The ability of the population to not only persist, but flourish downstream of a heavily populated urban area presented a unique opportunity to investigate a native species response to anthropogenic disturbance. This research revealed differences in Guadalupe Bass habitat associations and movements, contrasts in age and growth, and morphological variation across a gradient of disturbance throughout the Colorado River Basin. Results of this work provide information on the potential effects of human population growth and increased water withdrawals on Guadalupe Bass populations. Additionally, this work adds to an understanding of the unique Guadalupe Bass population found in the lower Colorado River and how it differs from upstream tributary populations. Gathering additional population-level information facilitates conservation actions critical to preserving preferred habitat and promoting growth rates for Guadalupe Bass in streams of different sizes and flow conditions while highlighting interpopulation differences that may warrant consideration for stocking programs and other management strategies. Key findings of this study were: • The similarity in response of growth rates to streamflow throughout the Colorado Basin suggests phenotypic plasticity in this trait rather than population-specific adaptations. • Reductions in streamflows in the Colorado River Basin, whether due to increased frequency of drought or increased anthropogenic water withdrawal, will likely result in lower Guadalupe Bass growth rates with the potential to impact the structure of populations. • Growth and recruitment showed a positive correlation with increased baseflows and mean monthly flows; however, continued assessment is necessary to determine a true relationship. • We documented morphological divergence among Guadalupe Bass populations in response to spatial and temporal environmental variation. These ecomorphological differences among populations provide insight into the ability of Guadalupe Bass to respond to the differing in-stream habitat and flow conditions between small ‘typical’ tributary systems and the mainstem Colorado River. • Morphological variation may be a population-level adaptation that potentially needs to be taken into consideration when choosing broodstock to maximize stocking success within a system. Understanding the morphological differences between Guadalupe Bass populations in response to local conditions could improve the success of restoration and supplemental stocking programs, especially in the ever-changing landscape of central Texas. • We established a baseline for understanding the morphological response of Guadalupe Bass to increased population growth and the threats posed by increased water withdrawals and impervious surface. • The mainstem population of Guadalupe Bass was generally more mobile, and more responsive to changes in streamflow, than tributary populations. The observed differences could influence the response of Guadalupe Bass populations to conservation and management actions, such as habitat restoration efforts. • Continued monitoring of recruitment and angler exploitation may be beneficial to identify any changes that could negatively impact the population. Conservation initiatives solely focused on physical instream or riparian habitat are unlikely to be as beneficial to Guadalupe Bass as those focused on restoring or maintaining adequate streamflow.
Pease AA, JE Pease, PT Bean, & TB Grabowski. 2022. Endemic Guadalupe Bass (Micropterus treculii) are supported by isotopically distinct resources in tributary versus mainstem river food webs. River Research and Applications. doi: 10.1002/rra.4015 \| Abstract	June 2022	We used stable isotope analysis to investigate differences in Guadalupe bass<i> Micropterus treculii</i> resource use that might be associated with population-level variation in main-stem river versus tributary stream habitats. <i>Micropterus treculii</i> from main-stem sites had more enriched δ<sup>13</sup>C and δ<sup>15</sup>N signatures compared to those collected in tributaries, likely reflecting greater importance of algae as a basal resource and influences of urban wastewater in main-stem habitats. Documenting ecological variation across ecosystem types is important to inform fish conservation efforts, especially for species that occupy a range of stream sizes.
Papastamatiou, Y.P., Caselle, J.E., Lowe, C.G., AM Friedlander. 2009. Scale dependent effects of habitat on movements and foraging strategies of blacktip reef sharks, Carcharhinus melanopterus, at Palmyra atoll: a predator dominated ecosystem. Ecology 90:996-1008	April 2009
Papastamatiou YP, JE Caselle, AM Friedlander, CG Lowe. 2009. Distribution, size frequency, and sex ratios of blacktip reef sharks, Carcharhinus melanopterus, at Palmyra Atoll: a predator-dominated ecosystem. J. Fish Biology 75:647-654.	February 2009
Papastamatiou YP, AM Friedlander, JE Caselle, CG Lowe. 2010. Longterm movement patterns and trophic ecology of blacktip reef sharks (Carcharhinus melanopterus) at Palmyra Atoll. Journal of Experimental Marine Biology and Ecology 386:94-102	February 2009
Paddack, MJ, J D Reynolds, C Aguilar, R S Appeldoorn, J Beets, E W Burkett, P M Chittaro, K Clarke, R Esteves, A C Fonseca, G E Forrester, A M Friedlander, and 23 others. 2009. Recent region-wide declines in Caribbean reef fish abundance. Current Biology 19:590-595	April 2009
Nalley, EM, LJ Tuttle, AL Barkman, EE Conklin, DM Wulstein, M Schmidbauer, and MJ Donahue. 2023. A systematic review and meta-analysis of the direct effects of nutrients on corals. *Science of the Total Environment*. 856(1): 159093. https://doi.org/10.1016/j.scitotenv.2022.159093	January 2023
Mueller JS, TB Grabowski, SK Brewer, & TA Worthington. 2017. Effects of temperature, dissolved solids, and suspended solids on the survival and development of larval Arkansas River Shiner. Journal of Fish and Wildlife Management 8:79-88. \| Abstract	June 2017	Decreases in the abundance and diversity of stream fishes in the North American Great Plains have been attributed to habitat fragmentation, altered hydrological and temperature regimes, and elevated levels of total dissolved solids and total suspended solids. Pelagic-broadcast spawning cyprinids, such as the Arkansas River Shiner Notropis girardi, may be particularly vulnerable to these changing conditions due to their reproductive strategy. Our objectives were to assess the effects of temperature, total dissolved solids, and total suspended solids on the developmental and survival rates of Arkansas River Shiner larvae. Results suggest temperature had the greatest influence on the developmental rate of Arkansas River Shiner larvae. However, embryos exposed to the higher levels of total dissolved solids and total suspended solids reached developmental stages earlier than counterparts at equivalent temperatures. Although this rapid development may be beneficial in fragmented waters, our data suggest it may be associated with lower survival rates. Furthermore, those embryos incubating at high temperatures, or in high levels of total dissolved solids and total suspended solids resulted in less viable embryos and larvae than those incubating in all other temperature, total dissolved solid, and total suspended solid treatment groups. As the Great Plains ecoregion continues to change, these results may assist in understanding reasons for past extirpations and future extirpation threats as well as predict stream reaches capable of sustaining Arkansas River Shiners and other species with similar early life-history strategies.
Mora C, OAburto-Oropeza, A Ayala Bocos, PM Ayotte, S Banks, AG Bauman, M Beger, S Bessudo, DJ Booth, E Brokovich, A Brooks, P Chabanet, J Cinner, J Cortés, JJ Cruz-Motta, A Cupul Magaña, E DeMartini, GJ Edgar, DA Feary, SCA. Ferse, A Friedlander, and 34 others. 2011. Global human footprint on the linkage between biodiversity and ecosystem functioning in reef fishes. PLoS Biol 9(4): e1000606. doi:10.1371/journal.pbio.1000606	April 2011
Monaco, ME, AM Friedlander, C Caldow, SD Hile, C Menza, RH Boulon. 2009. Long-term monitoring of habitats and reef fish found inside and outside the US Virgin Islands Coral Reef. Carib. J. Sci. 45:338-347.	July 2009
Monaco ME, AM Friedlander, SD Hile, SJ Pittman, RH Boulon. 2009. The coupling of St. John, US Virgin Islands marine protected areas based on reef fish habitat affinities and movements across management boundaries. Proceedings of the 11th International Coral Reef Symposium: 1022-1025.	July 2009
Miyazono S, AA Pease, TB Grabowski, & SR Fritts. 2019. Recruitment dynamics and reproductive ecology of Blue Sucker in Texas, with a focus on the Big Bend region of the Rio Grande. U.S. Department of Interior, Fish and Wildlife Service, Cooperator Science Series XXX-XXX. Washington, D.C. \| Abstract	June 2019	Blue Sucker (Cycleptus elongatus) is a state-listed threatened species in Texas and is considered vulnerable throughout its range. Once considered a single, wide-ranging species, blue suckers are now recognized as a complex of closely related, but genetically and morphologically distinct species within the genus Cycleptus, including an undescribed species within the Rio Grande Basin. Numerous factors likely are driving the decline of blue suckers in Texas, including flow alteration, water quality, habitat fragmentation, and changing land-use patterns, but it is not clear how these factors interact to influence the abundance and distribution of the species. Our research integrates a variety of methodologies to provide information critical to the conservation and management of Blue Sucker in the Sabine River (Texas and Louisiana) and Colorado River (Texas) and Rio Grande Blue Sucker (Cycleptus sp. cf. elongatus) in the Rio Grande. The objectives of this report are to 1) determine the habitat associations of the young-of-the-year (YOY) Rio Grande Blue Sucker; 2) assess the effects of flow regime on growth and recruitment of Blue Sucker in the lower Sabine River; and 3) examine differences in life-history traits of Blue Suckers and flow regime across river basins in Texas. This study is the first to quantitatively address the sequence of YOY blue sucker mesohabitat use and increases our understanding of early life history of blue suckers, and the results of this work will help to develop conservation and management strategies (e.g., prioritizing conservation areas, developing flow recommendation, etc.) for blue suckers throughout their geographic distribution. Key findings of this study were: 1) The body size of YOY Rio Grande Blue Sucker in pool habitats were significantly lower than that in other mesohabitats, suggesting that YOY Rio Grande Blue Sucker undergo onotogenetic habitat shifts into higher current velocity habitats as they grow. 2) Slow current areas, such as pools, could be important nursery habitats for small YOY Rio Grande Blue Sucker (total length ≤ 45 mm). 3) YOY Rio Grande Blue Sucker move into riffles and runs as they grow from April to June, suggesting that extreme low flow conditions during early summer may negatively affect the habitat quality or availability for YOY Rio Grande Blue Sucker. 4) The growth and recruitment of Blue Sucker in the lower Sabine River increased with increasing the river discharge from early summer to fall in our study areas. 5) The life-history traits of Blue Sucker differed between the lower Sabine River and the lower Colorado River: the total length and age of Blue Sucker in the lower Colorado River were larger than those of Blue Sucker in the lower Sabine River, and the growth and mortality rates of Blue Sucker of the lower Sabine River tended to be higher than those of the lower Colorado River. 6) Our results suggest that mesohabitat area and flow regime could be important factors determining the growth and recruitment of blue suckers, and the importance of these environmental factors could change according to the life-history stage (larval stage, juvenile stage, and adult stage). 7) Important areas for future research efforts include a) quantifying the differences in the mesohabitat area/quality/density among the three river basins; b) examining interactions between the spatial distributions of potential spawning habitat relative to suitable YOY mesohabitat and how variations in river flow influence their quality and connectivity to each other; and c) continuing to monitor the effects of flow regime on blue suckers for longer time periods.
Miyazono S, AA Pease, S Fritts, & TB Grabowski. 2020. Ontogenetic shifts in mesohabitat use of young-of-year Rio Grande Blue Sucker in the Big Bend region of the Rio Grande. Environmental Biology of Fishes 103:1471-1480. doi: 10.1007/s10641-020-01038-8 \| Abstract \| Publisher Website	December 2020	Changes in flow regime by anthropogenic activities is one of the primary environmental problems in riverine systems. It is important to understand how hydrologic conditions can affect ontogenetic habitat shifts of imperiled fishes in order to develop conservation and management strategies for each life-history stage. To better understand the factors affecting ontogenetic habitat shifts of an imperiled aridland river fish, we examined relationships between the abundance of young-of-the-year (YOY) Rio Grande Blue Sucker and various abiotic variables in the Trans-Pecos region of the Rio Grande in Texas, USA using open <i>N</i>-mixture modeling. In addition, we examined differences in Rio Grande Blue Sucker total length among three mesohabitat types (pool, riffle, and run). The results of open <i>N</i>-mixture modeling suggested that as pool area increased, the recruitment of Rio Grande Blue Sucker increased. Total length of YOY Rio Grande Blue Sucker also significantly differed among the three mesohabitat types. The total lengths of YOY Rio Grande Blue Sucker in pool habitats were lower than in other mesohabitats, suggesting that YOY Rio Grande Blue Sucker undergo ontogenetic habitat shifts into greater current velocity habitats as they grow. The habitat associations we documented support the growing body of research emphasizing the importance of maintaining sufficient and appropriately timed flows to avoid prolonged low flows that limit habitat availability for native fish species during sensitive life stages in the Rio Grande and other aridland rivers.
Long, J.M. and T.B. Grabowski. 2017. Otoliths. Pages 189-219 in M.C. Quist and D. Isermann, editors. Age and growth of fishes: principles and techniques. American Fisheries Society, Bethesda, Maryland.	November 2017
Kelly LW, Barott KL, Dinsdale E, Friedlander AM, Nosrat B, Obura D, Sala E, Sandin SA, Smith JE, Vermeij MJA, Williams GJ, Willner D, Rohwer F. 2011. Black reefs: iron-induced phase shifts on coral reefs. International Society for Microbial Ecology Journal.	October 2011
Keller, BD, Gleason DF, McLeod E, Woodley CM, Airame S, Causey BD, Friedlander AM, Grober-Dunsmore R, Johnson JE, Miller SL, Steneck R. 2009 Climate change, coral reef ecosystems, and management options for marine protected areas. Environmental Management. 44:1069-1088	July 2009
Jayewardene, D., and C. Birkeland. 2006. Fish predation on Hawaiian corals. Coral Reef 25: 328	March 2006
Jayewardene, D., M.J. Donahue, C. Birkeland. 2009. Effects of frequent fish predation on corals in Hawaii. 28(2) 499-506.	February 2009
Groeschel JR, S Miyazono, TB Grabowski, BD Cheek, & GP Garrett. 2020. Growth and habitat Use of Guadalupe Bass in the South Llano River, Texas. Journal of Fish and Wildlife Management 11:33-45. doi: 10.3996/022018-JFWM-015 \| Abstract \| Publisher Website	January 2020	Predicting how stream fishes may respond to habitat restoration efforts is difficult due, in part, to an incomplete understanding of how basic biological parameters such as growth and ontogenetic habitat shifts interact with flow regime and riverscape ecology. We assessed age-specific Guadalupe bass habitat associations at three different spatial scales in the South Llano River, a spring-fed stream on the Edwards Plateau of central Texas, and the influence of habitat and flow regime on growth. Substrates were classified using a low-cost side-scan sonar system. Scale microstructure was used to determine age and back-calculated size at age. Over 65% of captured Guadalupe bass were age-2 or age-3, but individuals ranged from 0-7 years of age. There was considerable overlap in habitat associations among age classes 1-3+, but age-0 Guadalupe bass tended to associate with greater proportions of pool and run mesohabitats with submerged aquatic substrates. While habitat metrics across multiple scales did not have a large effect on growth, discharge was negatively correlated with growth rates. Understanding age-specific Guadalupe bass habitat associations at multiple scales will increase the effectiveness of restoration efforts directed at the species and the use of low-cost side scan sonar seemed to provide an effective means of generating these data that can be adapted for other stream fishes.
Grabowski TB, SP Young, & P Cott. 2019. Looking for love under the ice: Using passive acoustics to detect burbot (Lota lota: Gadidae) spawning activity. Freshwater Biology. 65:37-44. doi: 10.1111/fwb.13314 \| Abstract \| Publisher Website	April 2019	The objective of this study was to assess the feasibility of collecting and using acoustic data to characterize the spawning activity and locations of Burbot under field conditions. Audio and video recordings of Burbot spawning aggregations were made through holes drilled into the ice at known spawning grounds at Moyie Lake in British Columbia, Canada. Acoustic behavior was related to video data to determine how acoustic activity correlated to any observed spawning behavior. Burbot vocalizations were difficult to identify with only about 6% of the recordings containing calls being successfully identified as such in the field. Burbot vocalized more often between sundown and sunrise than during daylight hours. Calls recorded at night tended to be lower frequency, longer duration and have lower bandwidth than those made during the day. Further, Burbot vocalizations were not recorded in conjunction with video recordings of spawning activity. These results suggest that while it may be feasible to use passive acoustic monitoring to locate Burbot spawning grounds and identify periods of activity, it does not seem to hold much promise for monitoring activity in real time.
Grabowski TB, JE Pease, & JR Groeschel-Taylor. 2018. Intraspecific differences in morphology correspond to differential spawning habitat use in two riverine catostomid species. Environmental Biology of Fishes 101:1249-1260. DOI: 10.1007/s10641-018-0772-9 \| Abstract \| Publisher Website	July 2018	Maintaining intraspecific diversity is an important goal for fisheries conservation and recovery actions. While ecomorphological studies have demonstrated intraspecific diversity related to feeding or flow regime, there has been little assessment of such variation in regards to spawning. We evaluated the relationship between individual morphology of Robust Redhorse and Notchlip Redhorse and variables describing the spawning habitat from which they were captured, such as current velocity, slope, and substrate particle size.. Robust Redhorse (n = 58) and Notchlip Redhorse (n = 43) were captured from the lower Savannah River, South Carolina-Georgia using prepositioned grid electrofishers, they were then measured, and photographed before being released. We constructed a truss network using digitized landmarks on each of the photographs. Relationships between the morphological and environmental datasets were assessed using canonical correlation analysis. In both species, these morphological predictors were correlated primarily to depth, though current velocity also contributed to the environmental canonical variable for Robust Redhorse. Robust Redhorse captured from the deeper locations with higher current velocities had lower aspect ratio heads than those of individuals captured from shallower areas. Notchlip Redhorse from shallower areas were deeper-bodied and had shorter trunks than counterparts from deeper areas. These differences suggest that ensuring spawning habitat heterogeneity may be an important component to conserving intraspecific diversity, particularly in systems where such habitat is limiting.
Grabowski TB, HM Williams, R Verble, A Pease, & JE Pease. 2019. Guadalupe Bass flow-ecology relationships; with emphasis on the impact of flow on recruitment. U.S. Department of Interior, Fish and Wildlife Service, Cooperator Science Series XXX-XXX. Washington, D.C. \| Abstract	December 2019	Guadalupe Bass Micropterus treculii is an economically and ecologically important black bass species endemic to the Edwards Plateau ecoregion and the lower portions of the Colorado River in central Texas. It is considered a fluvial specialist and as such, there are concerns that the increasing demands being placed upon the water resources of central Texas by growing human populations have the potential to negatively impact Guadalupe Bass populations. As such, this study assessed the relationship between Guadalupe Bass growth, feeding ecology, and streamflow. Sagittal otoliths were removed from Guadalupe Bass collected from throughout their range during 2015-2017 and used to estimate the age and back-calculate the growth trajectory of each individual. Additionally, young-of-year (YOY) Guadalupe Bass were collected every 10-14 days from two second-order streams, the North Llano River and South Llano River, in the Colorado Basin on the Edwards Plateau. Stomach contents of these individuals were identified and the effect of streamflow on the occurrence of the taxa comprising the stomach contents assessed. <br>Guadalupe Bass growth was greater in the Colorado and Guadalupe River basins, independent of stream order, and tended increase with increasing stream order within a basin. Growth was higher in streams and during years with lower spring and summer monthly median flows, lower minimum and maximum flows, slower rise and fall rates, and higher baseflows. Growth was not influenced by years with higher monthly median flows in winter. These results would seem to contradict previous research, but seem to be influenced by the fact that previous studies were conducted during a period of extensive drought, while the current study was conducted during relatively wet conditions. Taken together with previous studies, the current study suggests that Guadalupe Bass growth is sensitive to flow conditions and is lower in years with flow conditions that fall outside a basin- and stream order-specific optimal range for the species.<br>A total of 21 unique taxonomic groups were recovered from the stomachs of YOY Guadalupe Bass collected from the North Llano River and South Llano River. Aquatic insects, especially larval mayflies (Ephemeroptera), damselflies (Odanata: Zygoptera), and caddisflies (Trichoptera), were the most frequently encountered taxa. While there was no difference between the two rivers in stomach content composition, there was a strong longitudinal gradient in both systems with aquatic insects predominating at upstream sample sites and fishes being more common at downstream sites. Stream discharge during the 24 hours prior to collection did not have any influence on the probability of a taxa being found in Guadalupe Bass stomachs. <br>The results of this study support efforts to manage Guadalupe Bass populations at a sub-watershed basis and suggests that populations occupying the same stream order within a basin are likely to have similar responses to annual flow conditions. In addition, these results indicate that the lower Colorado River population may inhabit a unique set of conditions that has supported the development of a trophy Guadalupe Bass fishery. Further, this study highlights the need to incorporate a sufficient range of annual flow conditions to ensure that the influence of stream flow on fish growth is adequately assessed. While interannual variation in growth rates are seem to be capable of serving as a proxy for recruitment and year-class strength, long-term monitoring of recruitment paired with assessment of growth is necessary to further clarify the relationship between population density, flow regime, recruitment and growth and allow the construction of predictive models.
Grabowski TB, Benedum ME, Curley A, Dill De-Sa C, & Shuey ML. 2023. Pandemic-driven changes in the Hawaiian nearshore noncommercial fishery: analysis of catch photos posted to social media captures changing fisher behavior in response to disruptive events. PeerJ 11:e14994. https://doi.org/10.7717/peerj.14994 . \| Abstract \| Download \| Publisher Website	December 2023	How does a global pandemic alter fishing behaviors in Hawaiian nearshore fisheries? Using social media, we collect evidence for how nearshore fisheries are impacted by the global pandemic in Hawai’i. We later confirm our social media findings and obtain a more complete understanding of the changes in nearshore non-commercial fisheries in Hawaiʻi through a more conventional approach - speaking directly with fishers. We find that resource users posted nearly three times as often during the pandemic with nearly double the number of fishes pictured per post. We also find that individuals who fished for subsistence were more likely to increase the amount of time spent fishing and relied more on their catch for food security. Furthermore, we find that individuals fishing exclusively for subsistence were more likely to fish for different species during the pandemic than individuals fishing recreationally. Traditional data collection methods are resource-intensive and this study shows that social media data can be used to rapidly collect data and predict changes in nearshore fisheries due to large scale disturbances. As climate change threatens additional disturbances, it will be necessary for resource managers to collect reliable data efficiently to prevent species collapse and to better target monitoring and management efforts.
Grabowski TB and EC Franklin. 2017. What can volunteer angler tagging data tell us about the status of the Giant Trevally (ulua akuea) Caranx ignobilis fishery in Hawaii: revisiting data collected during Hawaiʻi’s Ulua and Papio Tagging Project 2000-2016. Report provided by the Cooperative Fish and Wildlife Research Unit Program under agreement with the U.S. Fish and Wildlife Service. U.S. Department of Interior, Fish and Wildlife Service, Cooperator Science Series FWS/CSS-126-2017, National Conservation Training Center. \| Abstract \| Download \| Publisher Website	September 2017	Giant Trevally (ulua aukea) Caranx ignobilis is one of the most highly prized and frequently targeted nearshore species. However, there is very little information on its current status in Hawaiian waters. This study uses mark-recapture data collected as part of recreational angler tagging program conducted by the Hawaii Department of Land and Natural Resources-Division of Aquatic Resources during 2000-2012. Mark-recapture data were used to estimate von Bertalanffy growth curve parameters and survivorship. Growth curves generated from the mark-recapture data suggested that Giant Trevally from the main Hawaiian Islands may be growing faster and reach a smaller maximum size than individuals in the Northwest Hawaiian Islands, but there are a number of issues rendering this conclusion uncertain. The survivorship of Giant Trevally was positively associated with age, in part due to ontogenetic habitat shifts that result in older fish moving to offshore habitats where they are less vulnerable to anglers. When compared to stock assessments performed using commercial landings data and fisheries-independent visual surveys, the mark-recapture data produced similar estimates for the average length of exploited fish, a metric highly negatively correlated to fishing mortality. These results emphasize the need for additional information on the biology of Giant Trevally in Hawaiian waters and suggest that the data collected from this recreational angler tagging program may be useful to generate reliable estimates of mortality for stock assessment purposes.
Grabowski TB & JH Grabowski. 2019. Early life history. Pages 133-168 in GA Rose (ed.). Atlantic Cod: the bio-ecology of the fish. John Wiley and Sons, New York. \| Abstract	January 2019	Like all marine fishes that undergo a planktonic life history stage, Atlantic cod must overcome a daunting set of challenges as part of their early life history. Atlantic cod must develop the morphological and physiological characteristics that will enable them to transition to a demersal, predatory existence as juveniles and adults, while retaining the ability to deal with the immediate and pressing challenges of a planktonic existence, e.g., avoiding predators while finding and subduing prey. At fertilization, an individual Atlantic cod embryo is cast adrift simultaneously with potentially millions of its siblings and half-siblings. Each embryo will take with it all of the parental investment it will ever receive in the form of energy reserves in its yolk sac provided by its mother and genetic material with a proven record of success from both parents. The parents of each embryo have themselves successfully completed the journey that this new generation of cod is about to undertake. The parents may have traveled hundreds of kilometers to release their offspring at the time and place where the most favorable conditions possible exist for success. Even so, the odds of any individual possessing the “winning” combination of pure luck and genetic fitness to overcome the specific hazards faced are infinitesimally small. Only the sheer number of embryos set adrift guarantees that there will be individuals capable of running the gauntlet. The truly amazing thing about cod is not the tremendous amount of mortality that occurs during this stage, but the fact that so many individuals survive. From a management perspective, understanding the factors influencing the high levels of mortality that occur during the early life history of cod is a critical component of predicting the future population size of cod stocks. This chapter details the early life history of the Atlantic cod starting at fertilization through larval development and continues with the descent of a juvenile cod from the plankton to suitable nursery habitat on the seafloor. This chapter also covers the early years, from habitat use to growth, diet, mortality and behavior, and ends as the juvenile cod begins to shift to adult habitats and behaviors.
Golbuu Y, A Friedlander. 2010. Spatial and temporal characteristics of grouper aggregations in marine protected areas in Palau, western Micronesia. Estuarine, Coastal, and Shelf Science. 92:223-231.	February 2011
Friedlander, A.M., L.M. Wedding, J. E. Caselle, B. M. Costa. 2011. Integration of remote sensing and in situ ecology for the design and evaluation of marine protected areas: examples from tropical and temperate ecosystems. Pages 245-279 In: Remote sensing of protected lands (Y.Q. Wang, ed.). CRC Press, Boca Raton, Florida.	November 2011
Friedlander, A.M. 2009. Marine protected areas. In: Encyclopedia of Islands (R. Gillespie and D.A. Clague, eds.). University of California Press. Pages 607-610.	August 2009
Friedlander AM, SA Sandin, EE DeMartini, E Sala. 2010. Habitat-specific characterization of the fish assemblage at a piscivore-dominated, pristine atoll in the central Pacific. Marine Ecology Progress Series 410: 219–231.	July 2010
Fagre, D.B., C.W. Charles, C.D. Allen, C. Birkeland, F.S. Chapin III, P.M. Groffman, G.R. Gunternspergen, A.K. Knapp, A.D. McGuire, P.J. Mulholland, D.P.C. Peters, D.D. Roby, and G. Sugihara. 2009. Thresholds of climate change in ecosystems. A report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research. U.S. Geological Survey, Reston VA, USA. 170 pages.	January 2009
DeMartini EE, Zgliczynski BJ, Boland RC, Friedlander AM. 2009. Influences of wind-wave exposure on the distribution and density of recruit reef fishes at Kure and Pearl & Hermes atolls, Northwestern Hawaiian Islands. Environmental Biology of Fishes 85:319-332	July 2009
DeMartini EE, TW Anderson, JC Kenyon, JP Beets, AM Friedlander. 2010. Management implications of juvenile reef fish habitat preferences and coral susceptibility to stressors. Marine and Freshwater Research. 61:532-540.	April 2010
DeMartini EE, TW Anderson, AM Friedlander, JP Beets. 2011. Predator biomass, prey density, and species composition effects on group size in recruit coral reef fishes. Marine Biology. 158: 2437-2447.	July 2011
Craig, P., C. Birkeland and S. A. Belliveau. 2001. High temperatures tolerated by a diverse assemblage of shallow water corals. Coral Reefs 20:185-189.	October 2001
Coastal salwater econsystems. Pages 133-151. D. Mueller-Dombois, K. W. Bridges, C. C. Daehler (eds. ). Biodiversity assessment of tropical ecosystems. PABITRA manual for interactive ecology and management. Bishop Museum Press. 255 p.	October 2008
Boulon RH, ME Monaco, AM Friedlander, C Caldow, J Christensen, C Rogers, J Beets, W Miller, SD Hile. 2009. An Ecological Correction to Marine Reserve Boundaries in the US Virgin Islands. Proceedings of the 11th International Coral Reef Symposium: 1074-1077.	July 2009
Birkeland, C., and P. K. Dayton. 2005. The importance in fishery management of leaving the big ones. Trends in Ecology and Evolution 20: 356-358	April 2005
Birkeland, C., A. Edward, Y. Golbuu, J. Guiterrez, N. Idechong, J. Maragos, G. paulay, R. Richmond, A. Tafileichig, and N. V. Valde. 2002. Freely Associated States. Pages 205-223 In D. D. Turgeon and R. G. Asch (eds. ), The state of coral reef ecosystems of the united States and Pacific Freely Associated States. 265 p.	July 2002
Birkeland, C., P. Craig, D. Fenner, L. Smith, W.E. Kleine, and B. Riegl. Geologic setting and ecological functioning of coral reefs in American Samora. Pp. 737-761. In B. Riegl and R. E. Dodge (eds. ) Coral Reefs of the U. S. A.	January 2008
Birkeland, C. 2004. Ratcheting down the coral reefs. BioScience 54: 1021-1027	October 2004
Birkeland, C. 2001. Implications for coral reef management and policy: relevant findings from the 9th International Coral Reef Symposium, Bali. Pages 55-56 In B. A. Best, R. S. Pomeroy, and C. M. Balboa (eds. ). U. S. Agency for International Development, the World resources Institute, Conservation international, and the International Society for Reef Studies. 113 p.	October 2001
Birkeland, C. 2001. Can ecosystem management of coral reefs be achieved? pp. 21-25 In: Best, B. A., and A. H. Bornbusch (Eds. ) Global trade and consumer choices: coral reefs in crisis. AAAS Publications, Washinton, D. C. 39 pp.	October 2001
Birkeland, C. 2000. The future of coral reefs. Galaxea (Japanese Coral Reef Society) 2:13-16.	October 2000
Barott KL, JE Caselle, EA Dinsdale, AM Friedlander, JE Maragos, D Obura, FL Rohwer, SA Sandin, JE Smith, B Zgliczynski. 2010. Natural History of the Lagoon at Caroline/Millennium Atoll, Republic of Kiribati. PLoS ONE 5(6):e10950	June 2010
Acre MR, TB Grabowski, DJ Leavitt, NG Smith, AA Pease, & JE Pease. 2021. Blue Sucker movement and habitat use in a regulated Texas River: implications for conservation and restoration. Environmental Biology of Fishes 104:501-516. doi: 10.1007/s10641-021-01093-9 \| Abstract	April 2021	Species conservation requires a clear understanding of the availability of suitable habitat and the subsequent use of those habitats. In cases where species declines have occurred and gone undetected to conservation managers, habitat alteration, fragmentation and loss are often the largest contributors. River fragmentation often results in altered flow regimes, which is considered the primary variable determining riverine habitat availability. Blue Suckers <i>Cycleptus elongatus</i> are associated with riffle and run habitat, a habitat type that is especially impacted when river flows are altered. The objective of this research was to identify the extent of suitable habitat and mobility for Blue Sucker in the Colorado River, Texas. To understand habitat selection and use, Blue Suckers (N = 49) were surgically implanted with combined acoustic radio transmitter tags. During 2015-2017, thirty-eight attempts were completed to relocate individuals using mobile tracking. Optimized hotspot analysis identified three river reaches critical for Blue Sucker that accounted for 20% of the study area. Blue Sucker used these locations year-round including during spawning. Habitats used by Blue Sucker were composed of gravel, cobble, boulder, and bedrock typically in riffle and run habitat. Additionally, mobility, as measured by home range size, increased as riffle density decreased. The larger home ranges were presumably to find suitable habitat to complete aspects of their life history. The results of this study suggest that suitable habitats are limited throughout the fragmented riverscape. Conservation action in the form of habitat construction or increased stream connectivity through barrier mitigation could have positive impacts on the future of Blue Sucker in the lower Colorado River, Texas.
Acre MR, C Alejandrez, J East, WA Massure, S Miyazono, JE Pease, EL Roesler, HM Williams, & TB Grabowski. 2017. Comparison of the precision of age estimates generated from fin rays, scales, and otoliths of Blue Sucker. Southeastern Naturalist 16:215-224. \| Abstract	July 2017	Evaluating the precision of age estimates generated by different readers and different calcified structures is an important part of generating reliable estimations of growth, recruitment, and mortality for fish populations. Understanding the potential loss of precision associated with using structures harvested without sacrificing individuals, such as scales or fin rays, is particularly important when working with imperiled species, such as Blue Sucker Cycleptus elongatus. We collected otoliths (lapilli), scales, and the first fin rays of the dorsal, anal, pelvic, and pectoral fins of nine Blue Sucker. Age estimates were generated from each structure by both experienced (n=5) and novice (n=4) readers. We found that independent of the structure used to generate the age estimates, the mean coefficient of variation (CV) of experienced readers was approximately 29% lower than that of novice readers. Further, the mean CV of age estimates generated from pectoral fin rays, pelvic fin rays, and scales were statistically indistinguishable and less than those of dorsal fin rays, anal fin rays, and otoliths. Anal, dorsal, and pelvic fin rays and scales underestimated age compared to otoliths, but age estimates from pectoral fin rays were comparable to those from otoliths. Skill level, structure, and fish total length were factors influencing reader precision between subsequent reads of the same aging structure from a particular fish. Using structures that can be harvested non-lethally to estimate the age of Blue Sucker can provide reliable and reproducible results, similar to those that would be expected from using of otoliths. Therefore, we recommend the use of pectoral fin rays as a non-lethal method to obtain age estimates for Blue Suckers.

Presentations

Presentations	Presentation Date
Wolff JP, LC Elkins, JS Perkin, JE Pease, TB Grabowski, PT Bean, NG Smith, & KM Metizen. Multiple tracking methods reveal Guadalupe Bass dispersal is consistent with the restricted movement paradigm. Annumal Meeting of the Southern Division of the American Fisheries Society. Norfolk, Virginia. 1-5 February 2023.	February 2023	We assembled Guadalupe Bass radio telemetry data from three rivers in the Colorado River Basin of Texas as well as mark-recapture data from fish fitted with passive integrated transponder (PIT) tags from three rivers in the Guadalupe River Basin of Texas and found a consistent pattern of leptokurtic movement distances, a telltale sign of heterogeneous movements by stationary and mobile fish. Our results provide information that will ultimately improve management and conservation by informing ha
Wolff JP, LC Elkins, JS Perkin, JE Pease, TB Grabowski, PT Bean, NG Smith, & KM Metizen. Guadalupe Bass (Micropterus treculii) movement is predictable: implications for conservation. Annumal Meeting of the Texas Chapter of the American Fisheries Society. Hunt, Texas. 3-5 February 2022.	February 2022	Fish movement and dispersal are critical for individual survival, (meta)population regulation, and community dynamics. We developed and validated a model to predict dispersal of Guadalupe Bass in the San Saba, Llano, and Pedernales as a method for estimating how far stocked fish might move to create an “area of influence” for stocking efforts to inform future conservation and management of the species.
Wolff JP, LC Elkins, JS Perkin, JE Pease, TB Grabowski, & PT Bean. Guadalupe Bass (Micropterus treculii) movement is predictable: implications for conservation. 151st Annual Meeting of the American Fisheries Society. Baltimore, Maryland. 6-10 November 2021.	August 2021	We developed models for movement using fish size, caudal fin aspect ratio, stream size, and time since tagging, then compared these expectations with observed field data. Our model matched field data and can serve as a method for estimating how far stocked fish might move to create an “area of influence” for stocking efforts to inform future conservation and management of the species.
Wedding, L. and A. Friedlander. 2009. A biogeographic assessment of the Hawaiian Islands Humpback Whale National Marine Sanctuary. Annual Meeting of the Hawaii Conservation Conference, Honolulu, Hawaii, 29 July, 2009.	July 2009
Tuttle Raz, L. J., D. Bartz, T. B. Grabowski, A. Larson, R. Masse, and D. McSwain. 2023. Exploring the life history and ecology of a threatened surgeonfish in Hawai‘i. Indo-Pacific Fish Conference, Auckland, NZ, 20-24 November 2023.	November 2023	This study characterized the basic life-history parameters of a culturally important surgeonfish (<i>Acanthurus achilles</i>) in Hawai'i that has recently experienced sharp declines in biomass, density, and average length in part of its range along west Hawai'i Island. Our results highlight that this species' biology (i.e., patterns of growth and reproduction) poses unique challenges to fisheries managers looking to ensure its sustainable harvest.
Tan E & TB Grabowski. Characterizing the fish assemblage at the Waiʻōpae tide pools: Do video and snorkeler surveys yield comparable results? Tropical Conservation Biology and Environmental Science Annual Research Symposium. Hilo, Hawaii. 5-6 April 2018.	April 2018	Our objectives were to determine whether similar results are produced by these two survey methods, camera-based and stationary point count (SPC) diver-based surveys, and if not, assess how they can be related to each other. The preliminary data suggest the two survey methods generate comparable estimates of species presence-absence, but may yield different estimates of assemblage structure.
Tabendera R & TB Grabowski. Comparison of fish assemblages and habitat use of native and introduced estuarine species in a fishpond complex in Hilo Hawaii. 11th Annual Tropical Conservation Biology and Environmental Science Research Symposium. Hilo, HI. 11-12 April 2019.	April 2019	In terms of their hydrology and geomorphology, Hawaiian fishponds are essentially artificial estuaries, but their ecology remains largely unexamined. Community composition differences were primarily driven by differences in salinity and locations with salinity <5 ppt contained lower overall richness and higher proportion of invasive species
Suarez B & TB Grabowski. Incorporating detection and occupancy coefficients of Pacific Islands coral reef fishes into biomass estimation procedures indicates biases of current methodologies. Kūlia i ka huliau—Striving for change: 2021 Hawaii Conservation Alliance Conference. 27-29 July 2021. Honolulu, HI [virtual].	July 2021	The biomass estimates generated from underwater visual surveys make two assumptions: reef fishes are perfectly detected, and all suitable habitat is occupied. These assumptions are unlikely to be met, and failing to account for them can result in biased biomass estimates. Our results represent the first effort to apply frequentist models to multiple reef fish species and estimate biomass over large regional scales; while this approach has assumptions requiring validation, it highlights several
Suarez B & TB Grabowski. Incorporating detection and occupancy coefficients of Pacific Islands coral reef fishes into biomass estimation procedures indicates biases of current methodologies. 11th Annual TCBES Research Symposium. Hilo, HI [virtual].	April 2021	The biomass estimates generated from underwater visual surveys make two assumptions: reef fishes are perfectly detected, and all suitable habitat is occupied. These assumptions are unlikely to be met, and failing to account for them can result in biased biomass estimates. Our results represent the first effort to apply frequentist models to multiple reef fish species and estimate biomass over large regional scales; while this approach has assumptions requiring validation, it highlights several
Suarez B & TB Grabowski. Estimating detection and occupation coefficients for reef fish in the western Pacific. 11th Annual Tropical Conservation Biology and Environmental Science Research Symposium. Hilo, HI. 11-12 April 2019.	April 2019	Accurate detection of size, abundance, and distribution during underwater surveys is vital for population estimation and occupancy modeling in fisheries management. Species level detectability and occupancy can be assessed using this robust data set due to the method utilized during the data collection was stationary point count with two adjacent divers collecting independent survey data.
Suarez B & TB Grabowski. Estimating detection and occupation coefficients for reef fish in the western Pacific Ocean to improve stock assessment. 2019 Joint Annual Conference of the American Fisheries Society and The Wildlife Society. Reno, NV. 29 September - 03 October 2019.	October 2019	Accurate detection of size, abundance, and distribution during underwater surveys is vital for population estimation and occupancy modeling in fisheries management. Species level detectability and occupancy can be assessed using this robust data set due to the method utilized during the data collection was stationary point count with two adjacent divers collecting independent survey data.
Stamoulis K, A Friedlander. 2012. Investigating Spillover for a Marine Protected Area in Hawaii. 12th International Coral Reef Symposium. Cairns, Australia, 8-13 July, 2012	July 2012
Smith N, MR Acre, D Buckmeier, & TB Grabowski. Can a river-reservoir interface serve as nursery habitat for riverine fishes? 151st Annual Meeting of the American Fisheries Society. Baltimore, Maryland. 6-10 November 2021.	November 2021	We sampled larval and juvenile fish assemblages in off-channel and main channel habitats of the Lake Livingston RRI and middle Trinity River, Texas to: 1) compare species composition and abundance, and 2) evaluate the influence of connectivity on larval and juvenile fish assemblages. Sites with frequent connectivity to the main channel, in particular the RRI off-channel habitats, had higher taxonomic richness, diversity, and overall abundance than similar habitats lacking this connectivity, sug
Roesler ER, MA Barnes, TB Grabowski, F Martinez-Andrade, & R Bittner. Influence of climate change, freshwater inflows, and changing land use on the distribution of Dwarf Seahorse on the Texas coast. 8th Texas Tech Annual Biological Sciences Symposium. Lubbock, Texas. 7-8 April 2017.	April 2017	Even though Dwarf Seahorse Hippocampus zosterae is considered a candidate for federal protection, virtually nothing is known of its distribution, population status, or habitat requirements. Understanding the factors influencing the current and future distribution of Dwarf Seahorse is an important first step towards determining the viability of the species in Texas waters.
Roesler ER, MA Barnes, TB Grabowski, F Martinez-Andrade, & R Bittner. Influence of climate change, freshwater inflows, and changing land use on the distribution of Dwarf Seahorse on the Texas coast. 16th Annual Texas Tech Graduate Student Poster Competition. Lubbock, Texas. 24 March 2017.	March 2017	Even though Dwarf Seahorse Hippocampus zosterae is considered a candidate for federal protection, virtually nothing is known of its distribution, population status, or habitat requirements. Understanding the factors influencing the current and future distribution of Dwarf Seahorse is an important first step towards determining the viability of the species in Texas waters.
Roesler EL, TB Grabowski, & MA Barnes. Data collection methods and species traits influence species distribution model predictions. 122nd Annual Meeting of the Texas Academy of Science. Brownwood, Texas. 1-2 March 2019.	March 2019	Overall, our research demonstrated the impact of data collection method and species traits on species distribution model (SDM) performance. Thus, consideration of these factors will improve the effectiveness of predictions from SDMs for conservation, management, and research.
Roesler EL, RE Bittner, TB Grabowski, and MA Barnes. Data collection methods and species traits influence species distribution model predictions. 103rd Annual Meeting of the Ecological Society of America. New Orleans, LA. 5-10 August 2018.	August 2018	We conducted a study to assess the influence of data collection methods on species distribution model (SDM) performance and determined whether SDM performance differs between taxa with different life history and physical traits in coastal habitats. Our results demonstrated an impact of data collection method and species traits on SDM performance and thus, these factors warrant consideration when using SDMs.
Rodriguez N & TB Grabowski. How will mass bleaching events affect the prevalence of ciguatera on Hawaiian reefs? 11th Annual TCBES Research Symposium. 15-16 April 2021. Hilo, HI [virtual].	April 2021	Ciguatera fish poisoning (CFP) is caused by consuming reef fishes containing toxins produced by dinoflagellates in the genus <i>Gambierdiscus</i>. The objectives of this study are to evaluate the relationship between coral cover loss, herbivorous fish biomass, and the probability of the high-level predator, Roi (<i>Cephalopholis argus</i>), and an herbivore targeted by anglers, Kole (<i>Ctenochaetus strigosus</i>), of being ciguatoxic using a commercially available fluorescent receptor binding
Perkin JS, JE Pease, & TB Grabowski. Loiterers, leavers, and leptokurtosis: Synthesizing movement ecology of Guadalupe Bass (Micropterus treculii). 2018 Annual Meeting of the Texas Chapter of the American Fisheries Society. College Station, Texas. 25-26 January 2018.	January 2018	Guadalupe Bass radio telemetry data synthesized from the Pedernales, South Llano, and Colorado Rivers of Texas indicated a consistent pattern of leptokurtosis, i.e., a distribution of movement distances characterized by a high peak representing loiterers and long tails representing leavers. Our findings have implications to Guadalupe Bass conservation and management, particularly in predicting the movement of stocked fish, assessing the potential for interactions with congeners, and evaluating
Pease JE, TB Grabowski, A Pease, & PT Bean. Movements and habitat use of Guadalupe Bass using radio telemetry in the lower Colorado River, Texas. 146th Annual Meeting of the American Fisheries Society. Kansas City, KS. 22-25 August 2016.	August 2016	revise this to reflect bass not suckers
Miyazono, S, S Fritts, TB Grabowski, B Grisham, K Mayes, & PT Bean. N-mixture modeling for juvenile Rio Grande Blue Sucker in the Trans-Pecos region of the Rio Grande. 2016 Annual Meeting of the Desert Fishes Council. Albuquerque, NM. 15-19 November 2016.	November 2016	Numerous factors are likely driving the decline of Blue Suckers in Texas, including flow alteration, water quality, habitat fragmentation, and changing land use patterns, but it is not clear how these factors interact to influence the abundance and distribution of blue suckers. Our results suggest that slow current areas could be important nursery habitat for juvenile Rio Grande Blue Sucker in the Trans-Pecos region of the Rio Grande, and that changes in flow regime that affects the availabilit
Miyazono, S, S Fritts, TB Grabowski, B Grisham, K Mayes, & PT Bean. Habitat associations of juvenile Rio Grande Blue Sucker in the Trans-Pecos region of the Rio Grande. 2017 Annual Meeting of the Texas Chapter of the American Fisheries Society. Corpus Christi, Texas. 19-21 January 2017.	January 2017	Blue Sucker Cycleptus elongatus is a state-listed threatened species in Texas and is considered vulnerable throughout its range. Once considered a single, wide-ranging species, blue suckers are now recognized as a complex of closely related, but genetically and morphologically distinct species within the genus Cycleptus, including an undescribed species within the Rio Grande Basin. Numerous factors are likely driving the decline of Blue Suckers in Texas, including flow alteration, water quality
Miyazono S, A Pease, S Fritts, TB Grabowski, B Grisham, K Mayes, S Magnelia, & PT Bean. Habitat associations of young-of-the-year Rio Grande Blue Sucker in the Trans-Pecos region of the Rio Grande. 2018 Annual Meeting of the Texas Chapter of the American Fisheries Society. College Station, Texas. 25-26 January 2018.	January 2018	Numerous factors are likely driving the decline of Blue Suckers in Texas, including flow alteration, water quality degradation, habitat fragmentation, and changing land use patterns; but it is not clear how these factors interact to influence the abundance and distribution of blue suckers. While the initial abundance and recruitment of Rio Grande Blue Sucker was positively correlated with pool area, our results suggested that apparent survival probability was not correlated with habitat.
Mikkelsen AB & TB Grabowski. All available science: Combining volunteer fish survey data and scientific monitoring to track long-term shifts in the reef fish assemblage structure on Hawaiian reefs. Tropical Conservation Biology and Environmental Science Annual Research Symposium. Hilo, Hawaii. 5-6 April 2018.	April 2018	Our objective is to evaluate changes in fish assemblages at windward and leeward sites off Hawaii, Maui, Oahu, and Kauai during 2000-2017 using fish survey data (n=15,159 surveys) collected by both agency biologists and citizen scientists and maintained by the Reef Environmental Education Foundation (R.E.E.F.). Our results demonstrate how citizen science and traditional monitoring can help track the complex changes across broad spatial and temporal scales that coral reef fish assemblages are un
Mikkelsen AB & TB Grabowski. All available science: Combining volunteer fish survey data and scientific monitoring to track long-term shifts in the reef fish assemblage structure on Hawaiian reefs. 25th Annual Hawaiʻi Conservation Conference. Honolulu, Hawaii. 24-26 July 2018.	July 2018	Our objective is to evaluate changes in fish assemblages at windward and leeward sites off Hawaii, Maui, Oahu, and Kauai during 2000-2017 using fish survey data (n=15,159 surveys) collected by both agency biologists and citizen scientists and maintained by the Reef Environmental Education Foundation (R.E.E.F.). Our results demonstrate how citizen science and traditional monitoring can help track the complex changes across broad spatial and temporal scales that coral reef fish assemblages are un
Massure WA, TB Grabowski, & T Arsuffi. Evaluating effects of drought and anthropogenic influences on the growth of stream fishes on the Edwards Plateau, Central Texas. 71st Annual Conference of the Southeastern Association of Fish and Wildlife Agencies. Louisville, KY. 29 October-01 November 2017.	October 2017	Drought and flow regime alteration have the potential to affect fish growth through numerous mechanisms and in so doing, can greatly influence demographic processes, such as recruitment and mortality. Our results will provide a better understanding of how drought coupled with anthropogenic alterations affect the overall growth rate of stream fishes and will help improve decisions made for the management and conservation of stream fishes, particularly those related to water management and instre
Life history and fishery for Hawaii's bonefish. 2011. 4th International Bonefish and Tarpon Symposium. Bonefish and Tarpon Trust. Dania Beach, Florida. November 11-12, 2011.	November 2011
Lessons and recommendations in the site-based manual removal of an invasive coral reef fish. Int. Marine Conservation Congress. Victoria, Canada, May 2011	May 2011
Kulbicki M, Arias-Gonzales E, Bellwood D, Chabanet P, Floeter S, Friedlander A, McClanahan T, McPherson J, Mouillot D, Parravicini V, Tittensor D, Vigliola L, Worm B. 2012. Connectivity, species size and the functioning of reef fish assemblages. 12th International Coral Reef Symposium, Cairns, Australia, 8-13 July, 2012	July 2012
Jayewardene, D. and C. Birkeland. June 04. Larval supply is not always key to coral recruitment. 10th International Coral Reef Symposium. Okinawa, Japan.	June 2004
Is ecosystem management achievable under constraints of the Magnuson-Stevens Act? University of Guam Marine Laboratory.	January 2002
Invited as the only scientist to testify as an “expert” for the Interagency Ocean Policy Task Force Pacific islands Public Meeting on September 29. Testimony on Preservation and conservation of marine resources in the tropical Pacific	September 2009
Honea J & TB Grabowski. Patterns of morphological variation in an introduced population of Peacock Grouper Cephalopholis argus around Hawai'i Island. 11th Annual TCBES Research Symposium. 15-16 April 2021. Hilo, HI [virtual].	April 2021	Morphological plasticity is an important attribute in defining the niche space of a species and can be predictive of the ability of an introduced species to establish itself. However, morphological plasticity in reef fishes, be they native or introduced, has not been extensively examined. Our results suggest that the plasticity of Peacock Grouper morphology potentially allows the species to occupy a broad range of habitats, particularly in the absence of other serranids and similar predatory sp
Hill SA, HM Williams, TB Grabowski, & R Verble. Population estimation of Guadalupe Bass in the North Llano River. 2018 Annual Meeting of the Texas Chapter of the American Fisheries Society. College Station, Texas. 25-26 January 2018.	January 2018	The habitat associations and population dynamics of Guadalupe Bass has been evaluated in the relatively undisturbed system, but there has been little work conducted in more disturbed systems, such as the North Llano River. Our results suggest that maintaining streamflow and habitat connectivity will be important to supporting healthy Guadalupe Bass populations throughout the NLR and other streams in central Texas.
Grabowski TB. #The_fish_was_HOW_big_really?: Overcoming biases and applying unconventional data sources to support coral reef fishery management. NOAA Coral Collaboration [online monthly seminar series]. 10 August 2023.	August 2023	Unconventional data sources, particularly social media platforms and citizen science, offer a potential treasure of timely fisheries-dependent and independent data available at a range of spatial scales that can be gathered with minimal resources. However, understanding the biases inherent with these data and identifying appropriate ways to analyze the data to account for these biases remains a major impediment to their application to management questions.
Grabowski TB & AB Mikkelsen. Using citizen science to evaluate the influence of marine ornamental fishery on Hawaiian reef fish occurrence and abundance. 2019 Joint Annual Conference of the American Fisheries Society and The Wildlife Society. Reno, NV. 29 September - 03 October 2019.	October 2019	The impact of the marine ornamental fishery on the populations of targeted reef fishes is a contentious issue in Hawaii, in large part because the data necessary to assess impact do not exist on sufficient spatial or temporal scales. For most of the top species, there was no evidence that being targeted in the marine ornamental fishery influenced their occurrence or reported abundance in volunteer citizen diver surveys.
Grabowski TB & AB Mikkelsen. Using citizen science to evaluate the influence of marine ornamental fishery on Hawaiian reef fish occurrence and abundance. 11th Annual Tropical Conservation Biology and Environmental Science Research Symposium. Hilo, HI. 11-12 April 2019.	April 2019	The impact of the marine ornamental fishery on the populations of targeted reef fishes is a contentious issue in Hawaii, in large part because the data necessary to assess impact do not exist on sufficient spatial or temporal scales. For most of the top species, there was no evidence that being targeted in the marine ornamental fishery influenced their occurrence or reported abundance in volunteer citizen diver surveys.
Friedlander, A.M., 2012. Understanding coral reef ecosystems using a seascape approach. First Joint Institute of Marine and Atmospheric Research/Pacific Island Fisheries Science Center Symposium. Honolulu, Hawaii, February 29, 2012	February 2012
Friedlander, A.M. 2012. Kahekili fisheries creel surveys: what we have learned. Hawaii Coral Program-Sharing Session. Honolulu, Hawaii. February 14, 2012.	February 2012
Friedlander, A.M. 2011. Motu Motiru Hui Marine National Park, Chile: high biodiversity in a remote coral reef ecosystem. 25th International Congress for Conservation Biology, University of Auckland, New Zealand. December 2-4, 2011	December 2011
Friedlander, A.M. 2011. Marine protected areas and community-based management in Hawaii: sustainability for the future. Maui Nui Marine Resource Council. Kihei, Maui. February, 11, 2011.	February 2011
Friedlander AM, Williams I, Donovan M. 2012. Meta-analysis of reef fish data in Hawaii to examine natural and anthropogenic processes. Hawaii Coral Program-Sharing Session. Honolulu, Hawaii. November 2, 2012.	November 2012
Friedlander AM, EE DeMartini, E Brown, J Beets, J Miller. 2012. How top-down control by predatory fishes and humans influence reefs. 12th Int. Coral Reef Symposium, Cairns, Australia, 8-13 July 2012.	July 2012
Efficacy of marine protected areas in the Hawaiian Archipelago: importance of size, habitat, and protection. 1st Int. Marine Conservation Congress. Fairfax, Virginia. May 18-24 2009	May 2009
Edwards C, A Friedlander, A Green, S Sandin, J Smith. 2012. Systematic effects of fishing on global coral reef herbivore populations. 12th International Coral Reef Symposium. Cairns, Australia, July 8-13, 2012.	July 2012
East J, TB Grabowski, & T Birdsong. Assessment and monitoring of newly established public river access and conservation areas. 146th Annual Meeting of the American Fisheries Society. Kansas City, KS. 22-25 August 2016.	August 2016	Understanding the potential impacts to the newly accessible river segments and how to manage them sustainably requires precise estimates of how the public is using these sites. These results will be used to develop protocols for conducting baseline assessments and monitoring of riparian and instream habitats, biological resources, and public use at newly acquired public access lease sites, and to determine the best management practices to apply at these sites to both ensure healthy rivers and s
Donovan MK, ID Williams, J Dierking, AM Friedlander. 2012. Multi-scale demographic trends in an introduced Hawaiian reef fish. 12th International Coral Reef Symposium, Cairns, Australia, 8-13 July, 2012.	July 2012
Conklin E, C Birkeland, A Friedlander, J Giddens, K Stamoulis, C Wiggins. 2012. Effects of Introduced Predatory Grouper Roi on Hawaiian Fish Assemblage. 12th International Coral Reef Symposium, Cairns, Australia, July8-13 2012	July 2012
Coastal and marine spatial planning for Hawaii and the Pacific Islands. USGS Coastal and Marine Spatial Planning workshop for the western US. Sausalito, CA. Dec. 2010	December 2010
Closing talk at the Smithsonian Institution Research and Discoveries: the revolution of science through scuba	May 2010
Byers MN & TB Grabowski. Habitat use by Green Sea Turtle (Chelonia mydas) at Onekahakaha Beach Park, Hawaii Island. 25th Annual Hawaiʻi Conservation Conference. Honolulu, Hawaii. 24-26 July 2018.	July 2018	Our objectives are to categorize the habitat use patterns of Green Sea Turtles at Onekahakaha Beach Park in Hilo, Hawaii and evaluate whether human activity influences habitat selection. This effort to better understand how human activities influence habitat use of Green Sea Turtles is necessary to better model habitat suitability and predict carrying capacity.
Birkeland, C., R.H. Randall, and G. Paulay. Oct 00. Changes over 23 years in a coral community at a sewer outfall in a fast-current area of Palau. 9th International Coral Reef Symposium. Bali, Indonesia.	October 2000
Birkeland, C. Jun 01. Can coral reef resources be managed under constraints of the Magnuson-Stevens Act? Pacific Science Congress, Guam.	June 2001
Birkeland, C. Feb 01. Can ecosystem management of coral reef resources be achieved? Symposium on Global Trade and Consumer Choices: Coral Reefs in Crisis at the AAAS Annual Meeting. San Francisco, CA.	February 2001
Bartz DE & TB Grabowski. Troubled waters: Assessment of changing patterns in juvenile shark abundance using local ecological knowledge. 2023 Hawaii Conservation Alliance. 27-30 June 2023. Honolulu, Hawaii.	June 2023	The local ecological knowledge contributed by fishers suggests that fishing pressure, climate change, and changing land use patterns in the Hilo Bay watershed have altered the suitability of the bay as a nursery habitat for at least two species of coastal-pelagic sharks, and has identified potential options for restoration or management strategies.
Bartz D & TB Grabowski. The history of Hilo’s hammerheads: Reconstructing changes in the distribution and abundance of juvenile Scalloped Hammerhead Sharks in Hilo Bay, Hawai’i through the use of traditional ecological knowledge and indigenous knowledge. 11th Annual TCBES Research Symposium. 15-16 April 2021. Hilo, HI [virtual].	April 2021	This work will use traditional ecological knowledge to develop an baseline for the population of Scalloped Hammerheads in Hilo Bay, Hawai'i in order to inform management decisions regarding the species there.
Aggregating species level data at the functional level: what do we gain or loose? 1st Int. Marine Conservation Congress. Fairfax, Virginia. May 18-24 2009	May 2009
Acre, MR, TB Grabowski, D Geeslin, A Pease, & N Smith. Streamflow effects on recruitment and migration of Blue Sucker in the lower Colorado River, Texas. 2018 Annual Meeting of the Texas Chapter of the American Fisheries Society. College Station, Texas. 25-26 January 2018.	January 2018	The relationships between river discharge, migratory behavior, and Blue Sucker recruitment have not been thoroughly examined, particularly in southern portions of its range. Our results suggest that large-scale movements are related to seasonal changes in temperature and river discharge prior to relocation and that the population in the lower Colorado River has had limited recruitment, and stronger cohorts appear to be associated with years with higher discharge.
Acre, MR, TB Grabowski, D Geeslin, A Pease, & N Smith. Streamflow effects on recruitment and migration of Blue Sucker in the lower Colorado River, Texas. 2018 Annual Meeting of the Southern Division of the American Fisheries Society. San Juan, Puerto Rico. 7-11 March 2018.	March 2018	The relationships between river discharge, migratory behavior, and Blue Sucker recruitment have not been thoroughly examined, particularly in southern portions of its range. Our results suggest that large-scale movements are related to seasonal changes in temperature and river discharge prior to relocation and that the population in the lower Colorado River has had limited recruitment, and stronger cohorts appear to be associated with years with higher discharge.
Acre MR, TB Grabowski, D Geeslin, & A Pease. Movements and demography of Blue Sucker in the lower Colorado River, TX. 2017 2017 Spring Meeting of the Southern Division of the American Fisheries Society. Oklahoma City, Oklahoma. 02-05 February 2017.	February 2017	The primary objectives of this research were to assess effects of varied streamflow levels, regulated by water releases from upstream reservoirs, on Blue Sucker movement, habitat use, and recruitment in the lower Colorado River downstream of Austin, Texas. Preliminary results suggest the population in the lower Colorado River has had limited recruitment, and stronger cohorts appear to be associated with years with higher discharge.
Acre MR, TB Grabowski, D Geeslin, & A Pease. Movements and Demography of Blue Sucker in the lower Colorado River, TX. 2017 Annual Meeting of the Texas Chapter of the American Fisheries Society. Corpus Christi, Texas. 19-21 January 2017.	January 2017	The primary objectives of this research were to assess effects of varied streamflow levels, regulated by water releases from upstream reservoirs, on Blue Sucker movement, habitat use, and recruitment in the lower Colorado River downstream of Austin, Texas. Preliminary results suggest the population in the lower Colorado River has had limited recruitment, and stronger cohorts appear to be associated with years with higher discharge.
Acre MR, TB Grabowski, D Geeslin, & A Pease. Movements and Demography of Blue Sucker in the lower Colorado River, TX. 2017 Annual Meeting of the American Society of Ichthyologists and Herpetologists. Austin, Texas. 12-16 July 2017.	July 2017	The primary objectives of this research were to assess effects of varied streamflow levels, regulated by water releases from upstream reservoirs, on Blue Sucker movement, habitat use, and recruitment in the lower Colorado River downstream of Austin, Texas. Preliminary results suggest the population in the lower Colorado River has had limited recruitment, and stronger cohorts appear to be associated with years with higher discharge.
"Fish predation on coral reefs" Hanauma Bay Education Program, UH Sea Grant College program	July 2009

Theses and Dissertations

Theses and Dissertations	Publication Date
Tabandera RK. 2019. Comparison of fish assemblages and habitat use of native and non-native estuarine species a fishpond complex in Hilo, Hawai'i. MS thesis. University of Hawai'i at Hilo, Hilo, Hawai'i, USA.	December 2019
Smith, L. 2008. Fluctuating Reef Environments Maintain Coral Resilience. Department of Zoology, University of Hawaii. 144 pp.	May 2008
Pease JE. 2018. Variation and plasticity and their interaction with urbanization in Guadalupe Bass populations on and off the Edwards Plateau. Ph.D. dissertation. Texas Tech University, Lubbcok, Texas.	August 2018
Nakachi K. 2021. Heeding the history of Kahu Manō: developing and validating a pono photo-identification methodology for Tiger Sharks (Galeocerdo cuvier) in Hawaiʻi. M.S. thesis, University of Hawai'i at Hilo. HIlo, Hawaii.	December 2021
Meyer, A. 2008. An Ecological Comparison Of Cephlopholis Argus Between Native and Introduced Populations. Department of Zoology, University of Hawaii. 131 pp.	August 2008
Massure WA. 2016. Evaluating effects of drought and anthropogenic influences on the growth of stream fishes on the Edwards Plateau, Central Texas. MS thesis. Texas Tech University, Lubbock, Texas.	August 2016
Jayewardene, D. 2009. Effects Of Marine Protected Areas On Benthic Community Structure and Ecological Processes on Coral Reefs In Hawaii. Department of Zoology, University of Hawaii. 131 pp.	May 2009
Howard, K.G. 2008. Community structure, life history, and movement patterns of parrotfishes: large protogynous hermaphrodite fishery species.	March 2008
Dierking, J. 2007. Effects Of The Introduced Predatory Fish Cephalopholis Argus On Native Reef Fish Populations In Hawaii. Department of Zoology, University of Hawaii. 115 pp.	May 2007
Claisse, J.T. 2009. Life history and evolutionary ecology of yellow tang, Zebrasoma flavescens, with implications for fisheries management using a MPA network.	March 2009
Barshis, D. J. 2009. Plastic Versus Fixed Influences On Coral Response To Fluctuating Environmental Conditions: Sources Of Coral Resilience and Stress Tolerance In A Changing Climate. Department of Zoology, University of Hawaii. 200 pp.	August 2009

Technical Publications

Technical Publications	Publication Date
Wenger, AS, EA Gómez Juárez, J Thomas, T Amaya, C Corbin, J Edmond, K Falinski, J Hill, A Jenkins, SD Jupiter, CD Kuempel, JB Lamb, EM Nalley, S Omwenga, T Oza, EN Perez, LJ Tuttle Raz, and A Wakwella. In press. A guide for integrated conservation and sanitation programs and approaches. Wildlife Conservation Society. Pp. 1-119.	October 2023
Smith, L.W. and C. Birkeland. 2003. Managing NPSA's coral reefs in the face of global warming: Research Project Report for Year 1. Report submitted to the National park of American Samoa. 54 pp.	May 2003
Nalley, EM, LJ Tuttle, EE Conklin, AL Barkman, DM Wulstein, MC Schmidbauer, and MJ Donahue. A systematic review and meta-analysis of the direct effects of nutrients on corals. *NOAA Technical Report*, September 2022. 72 p.	September 2022
Friedlander, A.M., L.M. Wedding, E. Brown, M.E. Monaco. 2010. Monitoring Hawaii’s marine protected areas: examining spatial and temporal trends using a seascape approach. NOAA Technical Memorandum NOS NCCOS 117.	August 2010
Friedlander, A., K. Keller, L. Wedding, A. Clarke, M. Monaco (eds.). 2009. A Marine Biogeographic Assessment of the Northwestern Hawaiian Islands. NOAA Technical Memorandum NOS NCCOS 84. Prepared by NCCOS’s Biogeography Branch in cooperation with the Office of National Marine Sanctuaries Papahanaumokuakea Marine National Monument. Silver Spring, MD. 363 pp.	June 2009
Fisk, D., and C. Birkeland. Status of coral communities in American Samoa: a re-survey of long-term monitoring sites. A report prepared for Department of Marine and Wildlife Resources, American Samoa Government. 11 =+ 135 pp.	August 2002
Fenner, D., A. Green, C. Birkeland, C. Squair, and B. Carroll. 2008. Long term monitoring of Fagatele Bay National Marine Sanctuary, Tutuila Island, American Samoa: results of surveys conducted in 2001/8, including a re-survey of the historic Aua Transect. 47 pp.	March 2008
Birkeland, C., and S.A. Belliveau. 2000. Resurvey of the Aua Transect after ship removal. Report to the Government of American Samoa and NOAA, U.S. Department of Commerce. 5 p.	July 2000
Birkeland, C., A.L. Green, C. Mundy, and K. Miller. 2004. Long term monitoring of Fagatele Bay National Marine Sanctuary and Tutuila Island (American Samoa) 1985 to 2001: summary of surveys conducted in 1998 and 2001. Report to the National Oceanic and Atmospheric Administration, U.S. Department of Commerce. 158 pp.	June 2004

Cooperative Fish and Wildlife Research Units Program: Hawaii Education, Research and Technical Assistance for Managing Our Natural Resources

Hawaii Research Activities

Cooperative Fish and Wildlife Research Units Program: Hawaii
Education, Research and Technical Assistance for Managing Our Natural Resources