Recruitment of postlarval spiny lobster, stone crabs, and larval fish to back-reef nursery habitats in the Florida Keys, USA

Back reef areas contain a mosaic of relatively shallow habitats that serve as a key nursery for reef species. Expansive back reef habitats in the lower Florida Keys, USA border the Atlantic Ocean and the Gulf of Mexico. A combination of floating, artificial settlement substrates and plankton nets moored in channels connecting coastal waters and back reef habitats quantified spiny lobster (Panulirus argus) and stone crab (Menippe sp.) settlement, and larval fish ingress, respectively, during 1999 and 2002–2003. The key finding was that channels connecting coastal waters with back reef areas serve as conduits for ingressing larval spiny lobster, stone crabs, and fishes. The results highlight the important role of Atlantic Ocean sources of spiny lobster pueruli and lutjanid fish larvae in this back reef system, and Gulf sources of stone crabs. Spiny lobster settlement generally peaked in August and September and occurred on the Atlantic Ocean side of this back reef system; settlement of stone crabs peaked at the same time as spiny lobster yet occurred predominantly on the Gulf side. Recruitment of larval fish was higher on the Atlantic than Gulf side, with 37% of fish species collected nearly exclusively on the Atlantic side and about 25% collected nearly exclusively on the Gulf side. Channel habitats appear critical to supporting the nursery role of back reef habitats and should receive special consideration in future ecosystem studies, as well as during spatial planning and evaluations of essential fish habitat.