Site Fidelity of Oyster Reef Blennies and Gobies in Saltmarsh Tidal Creeks

Abstract

Blennies and gobies are among the most abundant fishes in western Atlantic and Gulf of Mexico estuaries. They establish nests and maintain territories in oyster reefs and around other shallow-water structures during warm months. In this study, site fidelity and movements were determined for adult striped blenny, naked goby, freckled blenny, crested blenny, and feather blenny, in descending order of abundance. Recaptures among 221 tagged fishes at nine intertidal oyster reefs in a southeastern U.S. saltmarsh estuary provided information about fidelity for individual oyster reefs and nest sites as well as the size of territories (areas used) around nest sites. An overall recapture rate of 94% for fishes on reefs where they were tagged indicated high fidelity. Total recapture rates for the four blenny species ranged from 38 to 50%, but the naked goby recapture rate was only 9%. Within a breeding season, fidelity for specific nest sites was 58% for all blennies and 17% for gobies. Movements away from nest sites were limited with 56% of all fishes re-occurring ≤ 1 m from the original tagging site. Territories of 84% of the recaptured fishes. Differences in species composition and abundance between reefs suggested species-specific preferences for habitat features. Crested blenny and freckled blenny were recaptured at nest sites with significantly more oyster cover than nest sites occupied by striped blenny. Blennies occupied nest sites for several months and across annual breeding seasons suggesting continued residency within small areas of individual oyster reefs throughout their lives. Strong fidelity for reefs and nest sites potentially makes blennies more susceptible to disturbances than gobies, but both may be vulnerable to habitat disturbance at scales < 5 m. Thus, blennies and gobies may be useful indicator species for changes within estuarine habitats and ecosystems.