Captive-Reared Dusky Grouper (Mycteroperca marginata) As an Alternative to Repopulation of Degraded Reef Habitats

Abstract

1. Abstract Captive fish have been extensively used for stock enhancement and conservation of coastal and marine habitats. Evaluation of the effectiveness of this practice, however, has not been as extensively demonstrated. Here we assessed acclimation of captive-reared dusky grouper to reef habitats as an indication of introduction success. Fish were reared in laboratory from eggs obtained from wild local stocks to early juvenile stage (approximately 5 cm total length). Early juvenile fish were transported to fish pens for grow out to approximately 20 cm total length. Fish were individually tagged with acoustic transmitters and released after the grow out phase. Tagged fish were released at three reef habitat stations. Two stations received five fish each and one received 15 fish. Tagged fish were monitored for 7 months. We observed high mortality at the station receiving 15 fish and low mortality at the other stations. Behavior of fish demonstrated a pattern of refuge use according to time-of-day following approximately 5 days of release. Tagged fish behavior indicated adaptation to new habitat, demonstrating that captive groupers are a viable option in population recovery of degraded reef habitats. 2. Keywords: <span style=font-size:10.0pt;font-family: times= new= roman,serif=> Conservation; Dusky Grouper; Mari Culture; Recovery; Reef Restoration; Telemetry 3. Abbreviations: IUCN : International Union for Conservation of Nature <span lang=PT-BR style=font-size:10.0pt; font-family: times= new= roman,serif;mso-ansi-language:pt-br=>GnRHa : Gonadotropin-Releasing Hormone Agonist IBAMA : <span style=font-size:10.0pt; font-family: times= new= roman,serif=>Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renov a veis (Brazilian Environment and Renewable Natural Resources Institute) <span lang=PT-BR style=font-size:10.0pt; font-family: times= new= roman,serif;mso-ansi-language:pt-br=> <span lang=PT-BR style=font-size:10.0pt; font-family: times= new= roman,serif;mso-ansi-language:pt-br=>Vemco : Acoustic Telemetry Company <span lang=PT-BR style=font-size:10.0pt; font-family: times= new= roman,serif;mso-ansi-language:pt-br=>V9 : Vemco 9 mm transmitter <span lang=PT-BR style=font-size:10.0pt; font-family: times= new= roman,serif;mso-ansi-language:pt-br=>VR2W : Vemco 69 kHz receiver