Seasonal patterns of habitat suitability and spatiotemporal overlap within an assemblage of estuarine predators and prey

Abstract

Subtropical estuaries often experience seasonal climatic shifts, which influence environmental conditions such as water temperature and salinity. The distribution of estuarine organisms depends on the availability of suitable environmental conditions, the extent of which may differ across seasons. Furthermore, ecological interactions among organisms, such as predation and competition, often occur when multiple species overlap spatiotemporally and can influence their distributions and abundances. Determining the habitat associations and overlap patterns among predator and prey species across seasons can thus enhance our understanding of ecosystem function. This study used a long-term monitoring data set to examine the habitat suitability and overlap patterns between 4 predator and 4 prey species in a northwestern Gulf of Mexico estuary. Seasonal (fall and spring) habitat suitability models and maps were created, which allowed for delineation of spatiotemporal overlap between predators and prey. Environmental drivers of habitat suitability differed among species, but temperature and salinity were frequently the most important variables. Seasonal differences in habitat suitability were observed for all species, but these differences were more notable for prey than for predators. Seasonality in habitat suitability was likely driven primarily by seasonal changes in environmental conditions and movements related to reproductive activities. Spatiotemporal overlap between predators and prey was observed primarily in whichever season each prey species was more abundant and in regions where highly suitable habitat was most ubiquitous for each predator. These results suggest that overlap between these predators and prey is highly seasonal, implying seasonality in the diets of predators and predation pressure on prey.