Species-Specific Distribution and Habitat Characteristics of Shark Nurseries in Gulf of Mexico Waters off Peninsular Florida and Texas

摘要

At least 16 species of coastal sharks from four families (Carcharhinidae, Sphyrnidae, Ginglymostomidae, Triakidae) utilize Gulf of Mexico waters off Florida and Texas as primary and/ or secondary nursery areas. From 1991 to 2004, data were collected on 12,879 neonates, young of the year, and older juveniles of these 16 species in the U.S. Gulf of Mexico, primarily in coastal waters of the Florida peninsula and secondarily along the Texas coast. Five main areas of Florida (Yankeetown, Tampa Bay, Charlotte Harbor, Ten Thousand Islands, and Florida Keys) and three areas of Texas (Sabine Pass, Matagorda Bay, and Corpus Christi) were studied as shark nurseries. In general, most pupping activity in these gulf nurseries occurs in the late spring and earlysummer and the neonate and young-of-the-year animals inhabit the primary nurseries throughout the summer and into the fall. Declining water temperatures in the fall typically are associated with the exit of sharks from these natal inshore waters. In somecases, annual cycles of philopatric behavior are indicated whereby juveniles of both large and small coastal species migrate back to the nurseries in spring and summer. In these cases, primary nurseries for neonates and young of the year may function additionally as secondary nurseries for older juveniles. The importance of Florida and Texas coastal habitats in the early life history of Gulf of Mexico sharks underscores the need for conservation of these areas to help rebuild depleted shark populations.