Status and Habitat Characteristics of the Saltmarsh Topminnow, Fundulus jenkinsi (Evermann) in Eastern Mississippi and Western Alabama Coastal Bayous
The saltmarsh topminnow, Fundulus jenkinsi (Evermann, 1892), occurs sporadically along the northern Gulf of Mexico and appears to prefer Spartina habitat. Throughout its range, it is considered rare or threatened and has been placed on the US Federal Register's List of Candidate Species. In order to determine the status and habitat characteristics of this species, we examined collections from 1985-1986, 1996, 1999, and 2001 from eastern Mississippi and western Alabama. We report on 868 F. jenkinsi collected in 82 locations using 414 seine hauls and 420 Breder traps over 40 dates. Results using all collections indicated F. jenkinsi is not as abundant as other fundulids in this area but is more abundant than previously thought. We also documented the first records for this species from the Pascagoula River drainage. For the Breder trap collections only, a stepwise linear regression indicated that water temperature and salinity explained 39.7% of the variance in log10 (mean CPUE + 0.5) over the time of this study and this relationship was significant (ANOVA, F3.59 = 13.95, P < 0.001 ). The equation log10 (mean CPUE + 0.5) = 1.623 - 0.0150 (salinity) + 0.77 (depth) - 0.0584 (water temperature) indicated that mean CPUE of F. jenkinsiwas higher when salinity and water temperature were lower. Using bag seine and Breder trap data, this species was most abundant (90.7% of total) in salinities ≤ 12‰ while being mainly collected in water depths near 0.5 m and water temperatures ≥ 20.0°C. We feel the use of sampling gear designed to collect resident marsh fishes is imperative and use of other gear types and/or variation in annual rainfall and the subsequent extent and patchiness of low salinity salt marsh area from year to year may explain why this species appears rare or absent in most fish studies of the northern Gulf of Mexico. Because of its distribution in low-salinity bayou habitats, this small fundulid will probably be continually placed in situations where the habitat will be impacted due to development.
Peterson, M. S., G. L. Fulling and C. M. Woodley.
Status and Habitat Characteristics of the Saltmarsh Topminnow, Fundulus jenkinsi (Evermann) in Eastern Mississippi and Western Alabama Coastal Bayous.
Gulf and Caribbean Research
Retrieved from http://aquila.usm.edu/gcr/vol15/iss1/7