Coral Reefs (2008) 27:311–319 DOI 10.1007/s00338-007-0329-4 123 REPORT Historical and contemporary evidence of a mutton snapper (Lutjanus analis Cuvier, 1828) spawning aggregation Wshery in decline R. T. Graham · R. Carcamo · K. L. Rhodes · C. M. Roberts · N. Requena Received: 15 July 2007 / Accepted: 4 October 2007 / Published online: 24 October 2007  Springer-Verlag 2007 Abstract ScientiWc information on reef Wsh spawning aggregation Wsheries is sparse in light of numerous regional declines and extirpations from overexploitation. Fisher interviews of the small-scale commercial mutton snapper (Lutjanus analis) spawning aggregation Wshery at Gladden Spit, Belize, suggests a historic decadal decline. The reported trend is supported by analysis of inter-seasonal catch and eVort and yield (2000–2002) that reveals a 59% decline in catch per unit eVort (CPUE) and a 22% decrease in mean landings per boat. Declining population-level trends are also supported by a signiWcant decrease in inter- annual median lengths of mutton snappers (2000–2006). These Wndings demonstrate the need for additional life history information that includes length-associated age and details on growth to provide clearer support of the eVects on, and responses by, populations following Wshing. In view of the historical changes to mutton snapper CPUE and landings at Gladden Spit and the Wshery-associated declines in Wsh spawning aggregations observed globally, a precau- tionary approach to spawning aggregation management is warranted that provides full protection from Wshing to enhance population persistence. The Wndings also highlight the need for substantially greater enforcement and long- term Wsheries monitoring under a comprehensive regional management strategy. Keywords Lutjanidae · OverWshing · Spawning aggregation · Belize · Marine protected area Introduction Fish that aggregate to reproduce at predictable times and sites are particularly vulnerable to capture (Sadovy and Domeier 2005). Indeed, historical and documented evi- dence from several tropical locales points to a local, regional and global pattern of over-exploitation, including the extirpation of reef Wsh spawning aggregations (FSA) (e.g., Sadovy and Eklund 1999; Sadovy et al. 2003). Responses by FSA to Wshing include changes to the repro- ductive population structure, such as decreases in mean Wsh size (e.g., Sadovy 1994), abundance (e.g., Claro et al. 2001), genetic diversity (Chapman et al. 1999) and altera- tions in aggregation sex ratio (Koenig et al. 1996). Within the Wshery, increasing eVort and declines in catch are often noted following intense Wshing of FSA (Beets and Fried- lander 1998; Matos-Caraballo et al. 2006). Consequently, interest is turning towards FSA conservation, with several Communicated by Biology Editor M.I. McCormick. R. T. Graham (&) Wildlife Conservation Society, c/o PO Box 37, Punta Gorda, Belize e-mail: rgraham@wcs.org R. Carcamo Belize Fisheries Department, Princess Margaret Drive, Belize City, Belize K. L. Rhodes College of Agriculture, Forestry and Natural Resource Management, University of Hawaii at Hilo, Hilo, HI, USA C. M. Roberts Environment Department, University of York, York YO10 5DD, UK N. Requena The Nature Conservancy, Meso-American Reef Program, Guatemala City, Guatemala