Abstract
Southwest Florida has experienced a significant increase in population since the 1960's. The increase in population has resulted in significant changes to the natural landscape and local watersheds. This study represents a long term evaluation of the fish community structure within local estuary waters between 1970 and 2013. The study takes place in the waters of Rookery Bay National Estuarine Research Reserve. The reserve was established in 1977, but prior to that a 2 year trawl study was conducted in the waters that would eventually become part of the research reserve. The original study conducted between 1970-1972 provided the methodology to support replicate studies in 20 year increments 1990-1991 and again in 2011-2013. Since the original study a water control structure was constructed immediately upstream from the study location. This manuscript analyzes the fish community data in all three studies to identify potential changes that have occurred over a forty year time period that may be related to the anthropogenic alteration of the local watershed. Non-Parametric and parametric analyses were used to to compare the community structure of the three study periods. Results indicate that changes in community structure are most pronounced in the wet season and have a higher potential difference in community structure in sample sites closest to the upstream alteration of the watershed. Efforts to identify potential factors that contributed to the change in community structure centered around salinity, temperature, and changes in available habitat. Changes in the salinity profile of the estuarine system over time, increased water temperature and potential differences in habitat availability may have contributed to the overall changes of the community structure over the last forty years.