Using a Passive Acoustic Survey to Identify Spotted Seatrout Spawning Sites and Associated Habitat in Tampa Bay, Florida

Abstract

Abstract The spatial distribution of spawning activity can affect the reproductive success of certain fishes, and locating the key areas is critical to accurately assessing and managing their populations. We determined estuarine spawning locations for spotted seatrout Cynoscion nebulosus during the 2004 summer spawning season in Tampa Bay, Florida, using a passive acoustic survey. Sound production was evaluated at each of 754 randomly selected stations for the number of individuals calling and ranged from 1‐2 individuals to large aggregations. Spawning was identified by large aggregation sounds and was detected at 8% of the selected stations. There was seasonal variability in spawning, as spawning areas were inconsistently used throughout the season. Spatially, spawning occurred in all regions of the bay except for the Hillsborough Bay region. Most spawning took place in lower Tampa Bay and the eastern portion of the middle bay. Spawning occurred most frequently near the shoreline in areas of relatively high dissolved oxygen and in association with submerged aquatic vegetation. The variability in spawning habitat, as exhibited by both the disproportionate distribution of spawning sites across Tampa Bay and the inconsistent use of spawning sites, may serve to increase the resilience of the stock. As management directives evolve to encompass habitat‐focused strategies, surveys such as this one can supply data necessary for the creation of meaningful ecosystem‐based management plans.