Dataset for: High Site Fidelity of the Gulf Killifish (Fundulus grandis) in Northern Gulf of Mexico Marshes: An Empirical and Modeling Approach to Help Address Oil Effects

The gulf killifish (Fundulus grandis) has been frequently used as a sentinel species for studying impacts of the Macondo oil spill, largely as a result of its high abundance and widespread distribution in the affected area, intermediate trophic position, and tolerance to a wide range of environmental conditions. Compared to the Atlantic congener (F. heteroclitus), however, comparatively less life history information is available. Notably, the home range and dispersal capabilities remain unclear. Here, we present the results of a field study to determine the site fidelity of gulf killifish (>40mm TL) using four hydrologically separated tidal marsh creeks (<60 m in length) near Cocodrie, LA. Wire tags were injected into the dorsal musculature of at least 89 fish per site before they were released at a central release point in each creek, and recapture efforts were made at 5-10 meter intervals meter intervals along the creek length (30-90m) 1-2x per month initially and at a decreasing frequency up to 1 year post-release. Results indicate that, similar to F. heteroclitus, F. grandis exhibit high site fidelity, with initial recapture rates as high as 49% and some recaptures occurring after 1 year. Given the use of gulf killifish as an ecological indicator during recent evaluations of the Macondo spill, this information is useful to a wide audience seeking to determine the effects of the spill and suggest that observed responses to oil are likely to be local and, as a result, F. grandis likely provide reliable metrics of site-specific oil exposure throughout the region. Additional Data Contributors/ Authors Ken Able (PI), Olaf Jensen (Co-PI) and Joel Fodrie (Co-PI).