Threats, flows, and ecology: modelling and decision tools to support recovery of listed and at-risk species in the Apalachicola-Chattahoochee-Flint (ACF) River Basin.
March 2020 - September 2021
We will provide expertise to ongoing USFWS efforts in the ACF Basin to recover listed species, conserve at-risk species, and implement an adaptive management process to minimize incidental take of listed species from water management operations. We will synthesize existing information to create an updated threats analysis and employ hydrologic modeling and spatial analyses to quantitatively assess the primary threats to recovery of the six listed freshwater mussels species in the ACF Basin: Purple Bankclimber (Elliptoideus sloatianus, T), Chipola Slabshell (Elliptio chipolaensis, T), Fat Threeridge (Amblema neislerii, E), Oval Pigtoe (Pluerobema pyriforme, E), Shinyrayed pocketbook (Hamiota subangulata, E), and Gulf Moccasinshell (Medionidus penicillatus, E). All species have five year reviews in process, and two are also in process for having full Species Status Assessments completed in the next year. Threats include water quantity and quality in the rivers of the basin, which are impacted by drought frequency and severity. Additionally, historical river dredging is hypothesized to have contributed to mussel decline in the Basin, and population increases have been observed for some species since dredging ceased in the early 2000s. However, navigation is an authorized purpose of the US Army Corps of Engineers (USACE), so future dredging is possible and analyzing how dredging areas may intersect with contemporary mussel distribution must be considered in understanding future scenarios for securing subpopulations of the ACF mussels. We will apply hydrologic modeling to evaluate alternative water management operations to investigate effects to at-risk species and assist in upcoming reanalysis of the ACF Biological Opinion. We will also engage with the ongoing Adaptive Management process with USFWS, USACE, and scientific experts to help develop decision endpoints. This project has multiple high value, decision-relevant deliverables to the Service.