Alabama Cave Shrimp ('Palaemonias alabamae') 5-Year Review: Summary and Evaluation

摘要

The Alabama cave shrimp is a rare, troglobitic cave shrimp that survives in only two of its three known locations. The population in its type locality, Shelta Cave, has not been seen since the early 1970s. Population levels in Bobcat Cave and the HGB (R. Blackwood, pers. comm. 2006) Cave system appear to be low but stable. The status of the newly identified population in Muddy Cave is unknown. The sighting in western Jackson County (Limrock Blowing Cave), by McGregor et al. (1994), should be further evaluated. Results from survey data throughout the range indicate that population levels remain low where the species exists. Specific life history and habitat needs have not been well documented. Water quality and suitable cave habitat continue to be chronically plagued by polluted surface runoff. Recent water quality data from Bobcat Cave indicates that polluted deep groundwater may also pose a potential impact and should be further evaluated. Many of the studies conducted over the past 13 years have advanced our understanding of surface/groundwater interactions, as well as how precipitation relates to the timing and magnitude of waters being delivered to caves. However, the cave environment is extremely dynamic and more research is needed to better understand the quality of water in caves and how and when it is delivered. This is a critical concept, not only for the cave shrimp, but for all karst dependent species. The Alabama cave shrimp, despite numerous surveys over the past fifteen years, remains extremely rare throughout its range and is in danger of extinction. According to recovery criteria (FWS 1997), a total of five viable populations in five distinct groundwater systems needs to be identified, protected, and documented as viable prior to downlisting the species. At the time of this review, there are only two confirmed populations in two separate groundwater basins.