COMPONENT 2A - Project 2A1 PCC development February 2009 TRAINING COURSE REPORT CCapture,apture, iidentidentifi ccationation aandnd ccultureulture ttechniquesechniques ooff ccoraloral rreefeef fi sshh llarvaearvae ((FrenchFrench PPolynesia)olynesia) AAuthor:uthor: VViliameiliame PitaPita WaqalevuWaqalevu Photo credit: Eric CLUA 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 for a contribution to conservation and sustainable development of coral reefs in the Pacifi c he Initiative for the Protection and Management The CRISP Programme comprises three major compo- T of Coral Reefs in the Pacifi c (CRISP), sponsored nents, which are: by France and prepared by the French Development Agency (AFD) as part of an inter-ministerial project Component 1A: Integrated Coastal Management and from 2002 onwards, aims to develop a vision for the Watershed Management future of these unique ecosystems and the communi- - 1A1: Marine biodiversity conservation planning ties that depend on them and to introduce strategies - 1A2: Marine Protected Areas and projects to conserve their biodiversity, while de- - 1A3: Institutional strengthening and networking veloping the economic and environmental services - 1A4: Integrated coastal reef zone and watershed that they provide both locally and globally. Also, it is management designed as a factor for integration between deve- Component 2: Development of Coral Ecosystems loped countries (Australia, New Zealand, Japan and - 2A: Knowledge, benefi cial use and management USA), French overseas territories and Pacifi c Island de- of coral ecosytems veloping countries. - 2B: Reef rehabilitation - 2C: Development of active marine substances The initiative follows a specifi c approach designed to: - 2D: Development of regional data base (ReefBase - associate network activities and fi eldwork projects; Pacifi c) - bring together research, management and develop- Component 3: Programme Coordination and Deve- ment endeavours; lopment - combine the contributions of a range of scientifi c - 3A: Capitalisation, value-adding and dissemina- disciplines, including biology, ecology, economics, law tion of CRISP results and social sciences; - 3B: Coordination, promotion and development - address the various land and marine factors aff ecting of CRISP activities coral reefs (including watershed rehabilitation and - 3C: Support to alternative livelihoods management); - 3D: Vulnerability of ecosystems and species - avoid setting up any new body but supply fi nancial - 3E: Economic task force resources to already operational partners wishing to develop their activities in a spirit of regional coo- peration. This is why the initiative was prepared on CRISP Coordination Unit (CCU) the basis of a call for proposals to all institutions and Programme Manager: Eric CLUA networks. SPC - PO Box D5 - 98848 Noumea Cedex New Caledonia Tel./Fax: (687) 26 54 71 E-mail: [email protected] www.crisponline.net CRISP is funded by the following partners : Photos credit: Eric Clua (if no specifi c mention). Printed at SPC • Copyright : CRISP Ambassade de France à Fidji UNIVERSITY OF THE SOUTH PACIFIC School of Marine Studies, Laucala Campus, Fiji Capture, Identification and Culture techniques of coral reef fish larvae (French Polynesia) By Viliame Pita Waqalevu Training course conducted from the 10th January to 15th February 2009 Supervisors: David LECCHINI (IRD - UR 128 CoReUs) Christophe BRIE (Tropical Fish Tahiti) Pascal DAYEZ-BURGEON (French Embassy at Fiji Islands) Institut de recherche pour le développement Page | 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. Je désire aussi remercier Mr. Pascal Dayez-Burgeon, 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 : Eric, Loic, Cécile, Jennifer, Elisabeth, … pour avoir mis la bonne ambiance au centre de recherche. Page | 2 FINANCEMENT DE L'ETUDE * Financement par l'ANR (Agence Nationale de la Recherche) : L'étude a été financée en partie par un financement ANR Jeunes Chercheurs (ANR-06-JCJC-0012-01; D. Lecchini; Coral Reefs; novembre 2006 / octobre 2009). * Financement par l’Ambassade de France à Fidji : Mr. Pascal Dayez-Burgeon a financé le voyage de l’étudiant Viliame Pita Waqalevu de Fidji à Tahiti. * Financement par le programme CRISP (Coral Reef Initiative in the South Pacific) : L'étude a été financée aussi en partie par un financement CRISP (Composante C2A, R. Galzin & D. Lecchini; janvier 2007 / décembre 2009). 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. Page | 3 ABSTRACT Fish larvae were sampled daily over 4 weeks using the crest net method on the Island of Moorea in the Society Archipelago, French Polynesia. A total of 71 species were identified with a total abundance of 1204 larvae. Handpicked larvae were then cultured to juvenile stage in an aquarium and 67 fish larvae photographed during larval stage and 16 larvae during juvenile stages, in order to observe the metamorphosis between these two stages in the larvae’s life cycle. Larvae were fed three times a day with artemia and artificial pellet feed during the duration of culture and mortality was minimized to <5%. Light traps were also trialed on three different sites on two nights around the new moon on the North Coast of Moorea in order to compare methods of larval capture and to observe which method yielded the higher species richness and abundance. Upon completion of this study all larvae and juveniles were released back into the lagoon. Page | 4 1) INTRODUCTION In coral reef ecosystems, the life cycle of most fish species includes a planktonic larval phase (in the open ocean), which usually lasts from three to six weeks, followed by a sedentary reef phase (in the lagoon) for the juveniles and adults (for review, see Werner 1988 – Fig. 1). During the oceanic phase, the larvae may move far from their native island due to currents and/or their swimming abilities. Then larvae return to the reef (natal or not) to continue their development into juveniles, then to adults. Generally larvae enter the lagoon across the reef crest by night (colonisation phase, Dufour and Galzin 1993). In the hours following this colonisation, larvae undergo metamorphosis and choose suitable habitats (settlement phase) based mainly on the characteristics of coral habitat and the presence or absence of conspecifics (individuals of same species) as well as other species (for review, see Doherty 2002). Life cycle of coral reef fish Ocean Lagoon Larvae Colonisation Settlement Oceanic Juveniles dispersion Recruitment Genital products Reproduction & eggs Adults Figure 1: Description of life cycle of coral reef fish Page | 5 Thus, most coral reef fishes have a larval oceanic pelagic phase that ultimately ends with settlement onto suitable benthic habitats on the reef. The success of the transition between the two different environments determines the fish’s settlement levels (Dufour and Galzin 1993). There is a great need to understand the complexity with which coral reef fish larvae choose an appropriate habitat. Studies of similar scope need to be undertaken with greater enthusiasm as its ramifications greatly affect Pacific Islanders and the natural stock of reef fish. As shown by the study undertaken by the University of the South Pacific and University of Perpignan (PhD student, Julien Grignon), fish larval capture, culture and release can be used as a tool for reef restocking, ornamental and aquarium trade or for food fish, local or live fish exportation. Colonization of fish involves the settlement of post-flexion larvae upon completion of pelagic phase and the transition into juvenile involves some nature of habitat association within the lagoon. The colonization process was observed to usually occur at night and in higher numbers during new moon periods than in full moon periods (Lecchini et al. 2004). This process concerns mainly post-flexion larval stage and juvenile stage (Dufour and Galzin 1993) as these are the larvae that are able to drift easily and passively over the reef crest (Sale 1991). Therefore, the most suitable method that can be utilized to capture these larvae is the crest net which actively filter larvae that are swimming in the water flowing from the ocean into the lagoon.