|Scientific Name:||Etheostoma okaloosae|
|Species Authority:||(Fowler, 1941)|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Reviewer(s):||Smith, K. & Darwall, W.R.T.|
|Facilitator/Compiler(s):||Hammerson, G.A. & Ormes, M.|
Listed as Least Concern because although the extent of occurrence is less than 1,000 km2, area of occupancy is less than 500 km2, and the species occurs in a small number of locations (six stream systems), population size is large, threats have been reduced, and current trend is stable or increasing.
|Range Description:||Range is restricted to six adjacent stream systems (in Boggy and Rocky bayous) draining into Choctawhatchee Bay, Okaloosa and Walton counties, Florida, USA (USFWS 2007, Page and Burr 2011). The species inhabits approximately 46,000 ha of watershed; 90% of total range is within the Eglin Air Force Base.|
Native:United States (Florida)
|Range Map:||Click here to open the map viewer and explore range.|
This species is known from six adjacent stream systems draining into the western end of Choctawhatchee Bay, Florida.
Total adult population size is estimated at 625,000 (USFWS 2007, 2011).
This species has been extirpated from about 9% of former distribution (USFWS 2007, 2011).
Large and increasing populations exist in the majority of the range (USFWS 2007, 2011).
|Habitat and Ecology:||This darter typically occurs along the margins of small to medium (1.5–12.2 meters wide, 0.15–1.2 meters deep) clear creeks fed by groundwater seepage, with slow to swift current and bottom of clean sand and, in areas of reduced current, mud or detritus; usually it is associated with aquatic vegetation, and it tends to avoid open sand stretches without cover and areas where stream flow is negligible (USFWS 1980, 1997; Kuehne and Barbour 1983; Burkhead et al. 1992; Page and Burr 2011). Vegetation, woody debris, and root mats are used as spawning substrate (USFWS 1997). Associated upland habitat is mostly pine-oak sandhills. Natural processes (e.g., fire, flooding, sediment transport, and vegetative succession) maintain headwater stream sections with characteristics that foster healthy populations (USFWS 1997).|
Local declines within and outside Eglin AFB have been associated with erosion and stream sedimentation (Burkhead et al. 1992). Improved resource stewardship on Eglin AFB has reduced threats to Okaloosa darter habitat (USFWS 2007, 2011). USFWS continues to work with Eglin AFB, the City of Niceville, and Okaloosa and Walton counties to restore additional habitat through the removal and replacement of road crossings and impoundments throughout the darter's range (USFWS 2011).
Competitive interactions with introduced Etheostoma edwini may affect the distribution and abundance of E. okaloosae in some areas while in other areas habitat degradation may be more influential in the distributions of the two species (Burkhead et al. 1992); however, available evidence indicates that E. edwini is not negatively affecting E. okaloosae in most areas (USFWS 2007).
Conduct controlled removal of E. edwini from Rocky and Swift creeks; monitor and control siltation and eutrophication. Establish a public education program and evaluate its success (USFWS 1997).
Water quality and quantity in all occupied habitats and their watersheds should be carefully protected.
Populations in and around Eglin Air Force Base need to be constantly monitored.
Investigate interactions with E. edwini, range expansion of E. edwini, and dependence on water quality.
|Citation:||NatureServe 2014. Etheostoma okaloosae. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 27 November 2014.|