Print Report
G820 Hawaiian Brackish Aquatic Vegetation Group
Type Concept Sentence: This coastal group is composed of rare, land-locked, variously brackish pools with indirect subterranean connections to the ocean. Vegetation is limited and includes a variety of algae (green, red), blue-green algae, and emergent vegetation, including Carex spp. and Sesuvium portulacastrum with a distinctive fauna.
Common (Translated Scientific) Name: Hawaiian Brackish Aquatic Vegetation Group
Colloquial Name: Hawaiian Brackish Aquatic Vegetation
Hierarchy Level: Group
Type Concept: This group is composed of rare, land-locked, variously brackish pools with indirect subterranean connections to the ocean. They occur on the coasts of Hawai`i, Maui, Moloka`i, O`ahu, and Kaho`olawe with most of the pools occurring on the Big Island. Vegetation is limited and includes a variety of algae (green, red), blue-green algae, and emergent vegetation, including Carex spp. and Sesuvium portulacastrum. The fauna is most distinctive and includes many endemic and native crustaceans, including shrimps (Halocaridina rubra), prawns, amphipods, and isopods, and small fish, and invertebrates such as the orange-black damselfly (Megalagrion xanthomelas), which is a rare, anchialine pool endemic. The pools are found on relatively recent lava flows or on uplifted coral beds (limestone). Fresh surface water and groundwater mix with seawater to create different salinity levels within and among pools. Water levels in pools may fluctuate with tidal changes, although delayed depending on the hydraulic conductivity of the substrates.
Diagnostic Characteristics: This aquatic group is composed of variously brackish (mesohaline) pools with an indirect subterranean connection to the ocean and lack a surface connection to the ocean. Vegetation is characterized by a variety of algae (green, red), blue-green algae, and emergent vegetation, including Carex spp. and Sesuvium portulacastrum.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: Stands occur as small patches below MMU and are restricted to certain shoreline habitats that are well documented. Anchialine pools occur elsewhere in coastal regions, especially on limestone geology such as in the Yucatan and some islands in the Caribbean where they are called cenotes or blue holes.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: The vegetation of this group is very limited and includes a variety of algae (green, red), blue-green algae, and emergent vegetation, including Carex spp. and Sesuvium portulacastrum. Other common pool vegetation may be present such as Bolboschoenus maritimus and Cyperus laevigatus. Non-native, invasive plants may be present but not dominant at the edge of pools, including Batis maritima, Leucaena leucocephala, Pluchea carolinensis, Prosopis pallida, and Schinus terebinthifolius.
Dynamics: The vegetation of this group is very limited; however, the fauna is most distinctive and includes many endemic and native crustaceans, including shrimps (Halocaridina rubra), prawns, amphipods, and isopods, and small fish, and invertebrates such as the orange-black damselfly (Megalagrion xanthomelas), which is a rare, anchialine pool endemic.
This group is highly threatened by both invasive plants and animals such as the introduced shrub Neurolaena lobata and Tahitian prawn (Macrobrachium lar). Other threats include impacts from humans such as diverting water sources, waste disposal and input of soap (Stone and Pratt 1994b).
This group is highly threatened by both invasive plants and animals such as the introduced shrub Neurolaena lobata and Tahitian prawn (Macrobrachium lar). Other threats include impacts from humans such as diverting water sources, waste disposal and input of soap (Stone and Pratt 1994b).
Environmental Description: This group is composed of rare, land-locked, often brackish pools with indirect subterranean connections to the ocean. They occur on the coasts of Hawai`i, Maui, Moloka`i, O`ahu, and Kaho`olawe with most of the pools occurring on the Big Island.
Climate: Climate is variable depending on which coast the pools occur and ranges from arid to moderately wet (Zones 1-6) of the 7 Moisture Zones developed for the Hawaiian Islands by Price et al. (2007). Pools in arid areas tend to be more brackish because of less freshwater dilution from less precipitation.
Soil/substrate/hydrology: The pools are found on relatively recent lava flows or on uplifted coral beds (limestone). Fresh surface water and groundwater mix with seawater to create different salinity levels within and among pools. Water levels in pools may fluctuate with tidal changes, although delayed depending on the hydraulic conductivity of the substrates. Pools in arid areas tend to be more brackish because of less freshwater dilution from less precipitation. On the Big Island, salt content in most Kona coast pools is near 15 parts per thousand (ppt), whereas salt content in pools on the wetter windward side of the island is around 6 ppt (Stone and Pratt 1994b). All anchialine pools have much lower salt content than the ocean which is 35 ppt (Stone and Pratt 1994b). Water levels in anchialine pools may fluctuate with tidal changes due to the coastal location and the connection with the ocean. However, these fluctuations may be delayed depending on distance from the coast and the hydraulic conductivity of the geological materials.
Climate: Climate is variable depending on which coast the pools occur and ranges from arid to moderately wet (Zones 1-6) of the 7 Moisture Zones developed for the Hawaiian Islands by Price et al. (2007). Pools in arid areas tend to be more brackish because of less freshwater dilution from less precipitation.
Soil/substrate/hydrology: The pools are found on relatively recent lava flows or on uplifted coral beds (limestone). Fresh surface water and groundwater mix with seawater to create different salinity levels within and among pools. Water levels in pools may fluctuate with tidal changes, although delayed depending on the hydraulic conductivity of the substrates. Pools in arid areas tend to be more brackish because of less freshwater dilution from less precipitation. On the Big Island, salt content in most Kona coast pools is near 15 parts per thousand (ppt), whereas salt content in pools on the wetter windward side of the island is around 6 ppt (Stone and Pratt 1994b). All anchialine pools have much lower salt content than the ocean which is 35 ppt (Stone and Pratt 1994b). Water levels in anchialine pools may fluctuate with tidal changes due to the coastal location and the connection with the ocean. However, these fluctuations may be delayed depending on distance from the coast and the hydraulic conductivity of the geological materials.
Geographic Range: This group is composed of land-locked, variously brackish pools that occur along the coasts of Hawai`i, Maui, Moloka`i, O`ahu, and Kaho`olawe with most of the pools occurring on the Big Island.
Nations: US
States/Provinces: HI
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.955785
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 5 Aquatic Vegetation Class | C05 | 5 |
| Subclass | 5.A Saltwater Aquatic Vegetation Subclass | S09 | 5.A |
| Formation | 5.A.3 Benthic Vascular Saltwater Vegetation Formation | F054 | 5.A.3 |
| Division | 5.A.3.Xd Tropical Saltwater Vegetation Division | D063 | 5.A.3.Xd |
| Macrogroup | 5.A.3.Xd.4 Polynesian-Eastern Melanesian Saltwater Vegetation Macrogroup | M177 | 5.A.3.Xd.4 |
| Group | 5.A.3.Xd.4.d Hawaiian Brackish Aquatic Vegetation Group | G820 | 5.A.3.Xd.4.d |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: No Data Available
- Brock, R., and J. Bailey-Brock. 1997. An unique anchialine pool in the Hawaiian Islands. International Review of Hydrobiology 83(1):65-75.
- Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
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- USGS and NPS [U.S. Geological Survey and National Park Service]. 2005. Inventory of anchialine pools in Hawai''i''s national parks. U.S. Geological Survey and National Park Service - Our Volcanic Public Lands. November 2005. USGS FS 2005-3129. 2 pp. [http://biology.usgs.gov/pierc/Plants,_Insects_&_Ecosystems/Anchialine_pools.pdf#search=%22anchialine%20pools%22] (accessed 2 March 2009).
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