Volume 63
High Larval Settlement of the Long-spined Black Sea Urchin, Diadema antillarum, in the United States Virgin Islands.
Authors
McCauley, S., E. Parish, T. Turner, and L. Walters Download PDF Open PDF in BrowserOther Information
Date: November, 2010
Pages: 512
Event: Proceedings of the Sixty-Third Annual Gulf and Caribbean Fisheries Institute
City: San Juan
Country: Puerto Rico
Abstract
Larval abundance is suggested to be a limiting factor for populations of the long black spiny sea urchin Diadema antillarum recovering from the 1983 - 1984 Caribbean-wide die-off, yet such data are scarce. Coral reef recovery may well depend on this keystone herbivore as well. Using methods comparable to similar previous studies in the Caribbean, this study is the first to quantify larval settlement rates on shallow water (< 7 m) coral reefs within the United States Virgin Islands. In January 2010, larval traps were deployed in two areas of low (0.21/m2 ± 0.09 SE) and high (2.75/m2 ± 0.44 SE) densities of adults in Brewers Bay, St. Thomas. Monthly settlement rates of juvenile Diadema to date are high (max. ~17/m2) compared to previous studies of settlement in nearshore reefs in Puerto Rico (max. ~0.3/m2) and the Florida Keys (max. 1.9/m2). Larval settlement appears to be seasonal, with all of the juveniles appearing between May - July 2010. Surprisingly, fewer juveniles settled in the area with the highest adult density, suggesting that post-settlement mortality is important. Quantifying larval settlement patterns allows managers to better understand factors affecting coral reef recovery.