COMPONENT 3C - Project 3C8 New techniques of reef fi sh postlarvae capture Mars 2010 MASTER INTERNSHIP REPORT Seensorynsory aabilitiesbilities aandnd bbrainrain aanatomynatomy ooff ccoraloral rreefeef fi sshh aatt llarvalarval sstagetage ((FFrrenchench Poolynesialynesia) AAuthor:uthor: RRynaeynae GGretareta LLanyonanyon The CRISP Coordinating Unit (CCU) was integrated into the Secretariat of the Pacifi c Community in April 2008 to insure maximum coordination and synergy in work relating to coral reef management in the region. The CRISP Programme is implemented as part of the policy developed by the Secretariat of the Pacifi c Regional Environment Programme to contribute to the conservation and sustainable development of coral reefs in the Pacifi c. he Initiative for the Protection and Management of This approach is articulated through a series of thematic T Coral Reefs in the Pacifi c (CRISP), sponsored by France objectives: and established by the French Development Agency Objective 1: Improved knowledge of the biodiversity, (AFD), is part of an inter-ministerial project that began in status and functioning of coral ecosystems. 2002. CRISP aims to develop a vision for the future of these Objective 2: Protection and management of coral unique ecosystems and the communities that depend on ecosystems on a signifi cant scale. Objective 3: Development of the economic potential them and to introduce strategies and projects to conserve represented by the use values and biodiversity of coral their biodiversity, while developing the economic and en- ecosystems. vironmental services that they provide both locally and Objective 4: Dissemination of information and know-le- globally. CRISP also, has a role in fostering greater integra- dge; and capacitybuilding and leadership with local, na- tion in this area between developed countries (Australia, tional and international networks. New Zealand, Japan, USA), French overseas territories and Pacifi c Island developing countries. The CRISP Programme comprises three major components: Component 1A: Integrated coastal management and The initiative follows a specifi c approach designed to: watershed management – associate networking activities and fi eldwork pro- – 1A1: Marine biodiversity conservation planning jects; – 1A2: Marine Protected Areas – bring together research, management and develop- – 1A3: Institutional strengthening and networking ment endeavours; – 1A4: Integrated coastal reef zone and watershed – combine the contributions of a range of scientifi c dis- management ciplines, including biology, ecology, economics, law Component 2: Development of coral ecosystems and social sciences; – 2A: Knowledge, benefi cial use and management – address the various land and marine factors aff ecting of coral ecosytems coral reefs (including watershed rehabilitation and – 2B: Reef rehabilitation management); – 2C: Development of active marine substances – avoid setting up any new body but supply fi nancial re- – 2D: Development of regional data base (ReefBase sources to already operational partners wishing to de- Pacifi c) velop their activities in a spirit of regional cooperation. Component 3: Programme coordination and development This is why the initiative was established on the basis – 3A: Capitalisation, value-adding and extension of of a call for proposals to all institutions and networks. CRISP programme activities – 3B: Coordination, promotion and development CRISP Coordinating Unit (CCU) of the CRISP programme Programme Manager: Eric CLUA – 3C: Support to alternative livelihoods SPC - PO Box D5 – 3D: Vulnerability of ecosystems and species 98848 Noumea Cedex – 3E: Economic task force New Caledonia Tel./Fax: (687) 26 54 71 E-mail: [email protected] www.crisponline.net CRISP is funded by the following partners: Ambassade de France à Fidji UNIVERSITY OF THE SOUTH PACIFIC School of Marine Studies, Laucala Campus, Fiji Sensory abilities and brain anatomy of coral reef fish at larval stage (French Polynesia) By Rynae Greta Lanyon Training course conducted from the 24th January to 27th February 2010 Supervisors: David LECCHINI (IRD - UR 227 CoReUs) Milika SOBEY, Joeli VEITAYAKI & Edward LOVELL (USP) Bernard MAIZERET (French Embassy at Fiji Islands) Institut de recherche pour le développement 1 REMERCIEMENTS Au terme de ces deux mois de recherche, je tiens à remercier toutes les personnes qui, de près ou de loin, scientifiquement, financièrement ou moralement, ont contribué à l'aboutissement de ce rapport. Je désire remercier David Lecchini, Chargé de recherche à l'Institut de Recherche pour le Développement (UR 128 Coreus) et Christophe Brié (Tropical Fish Tahiti) qui m'ont permis de réaliser ce stage. Je leur sais gré de m'avoir fait confiance tout au long de ce travail. I would like to thank the Professors Milika Sobey,Edward Lovell and Joeli Veitayaki to select me to participe at this training course. Vinaka… Je désire aussi remercier Mr. Bernard Maizeret, Conseiller de coopération et d’action culturelle à l’Ambassade de France à Fidji. Sans son aide, ce stage n’aura jamais vu le jour. Vinaka… Ce travail a été réalisé au Centre de Recherche Insulaire et Observatoire de l’Environnement à Moorea. Je tiens à remercier très chaleureusement Serge Planes, Yannick Chancerelle et René Galzin d'avoir entrepris de nombreuses démarches pour le bon déroulement du stage et m'avoir permis de loger au Centre de Recherche. Un immense merci aussi à Pascal, Benoit et Franck pour leur aide de tous les jours. Je tiens enfin à remercier mes collègues de Moorea : Viliame, Lindon, Cécile, Kevin, Moana … pour avoir mis la bonne ambiance au centre de recherche. 2 FINANCEMENT DE L'ETUDE * Financement par le programme CRISP (Coral Reef Initiative in the South Pacific) : L'étude a été financée par le programme CRISP : "Amélioration des techniques de capture des post-larves de poissons et de crustacés" (Composante C2A, R. Galzin & D. Lecchini; janvier 2010 / décembre 2010). L’initiative pour la protection et la gestion des récifs coralliens dans le Pacifique, engagée par la France et ouverte à toutes les contributions, a pour but de développer pour l’avenir une vision de ces milieux uniques et des peuples qui en dépendent ; elle se propose de mettre en place des stratégies et des projets visant à préserver leur biodiversité et à développer les services économiques et environnementaux qu’ils rendent, tant au niveau local que global. Elle est conçue en outre comme un vecteur d’intégration régionale entre états développés et pays en voie de développement du Pacifique. Le CRISP est un programme mis en œuvre dans le cadre de la politique développée par le Programme Régional Océanien pour l’Environnement afin de contribuer à la protection et la gestion durable des récifs coralliens des pays du Pacifique. * Financement par l’Ambassade de France à Fidji : Mr. Bernard Maizeret a facilité grandement l’obtention de mon Visa. 3 ABSTRACT Over a period of four weeks samples of larvae were collected using crest nets. A total of 2313 larvae were collected consisting of 32 families and 75 species. Following identification the seven selected species were put into aquaria’s to be used for visual cue experiments. Three of each species were put into ten percent formal for twenty fours for fixation before the brain was dissected, thirty nine species were dissected and photographs of their brain taken. After the pictures were taken the fish, fish with open cranium and the brain were again put into ten percent formol foe preservation. 4 1) INTRODUCTION The biodiversity is declining, and habitat destruction and degradation are now commonplace. Examples of degradation can be found throughout marine ecosystems, including estuaries, saltmarshes, soft-bottoms, hard-bottoms, and coral reefs (Hughes et al. 2003). The degradation in coral ecosystems is usually characterized by coral mortality from natural and anthropogenic stressors (e.g., disease, hurricane damage, pollution, temperature-induced bleaching). This decrease of coral cover opens space on most reefs and causes substantial increases in cover and biomass of rapidly growing fleshy and filamentous macroalgae which, in turn, limits the recovery of coral populations and then modify fish and invertebrates communities (Edmunds & Carpenter 2001). Thus, areas experiencing perturbance often exhibit declines in adult populations, leading to a higher rate of extirpation than in pristine habitat, and the persistence of species in the area becomes reliant on the "rescue" effect of recruitment (Hanski & Gilpin 1997). The potential of the areas population to be supplemented by recruits, however, depends on whether pelagic larvae detect an appropriate habitat in that area and then settle and persist in that habitat (Sale 2002). Thus, the abundance and diversity of coral reef fish depend mainly on the recruitment success (Sale 2002), which is characterized by important seasonal and inter-annual variations (Doherty & Williams 1998). Recruitment success depends, for a large part, on the number of survivors among pelagic larvae in the water column (Boehlert 1996). The life cycle of coral reef fishes includes two major phases - a planktonic phase and a demersal or benthic phase. Coral reef fish spawn to produce eggs and larvae that disperse into the open ocean. After development as plankton, larvae recruit back to reefs. Most coral reef fishes have complex life cycles, involving the broadcast of eggs or larvae into the water column (Fontes et al. 2009), fertilized eggs disperse into the open ocean. Other species