Méthodologie d'étude des impacts d'une centrale d'énergie thermique des mers (ETM) en Martinique

L'ETM (énergie thermique des mers) est une énergie marine renouvelable qui utilise la différence de température entre les eaux chaudes de surface et les eaux froides profondes. Dans le cadre d'un projet d'implantation d'une centrale ETM offshore en Martinique, une première étude d'impact environnemental a été réalisée afin d'alimenter le débat public à venir. Compte tenu de la nouveauté introduite par ce type de projet, des méthodes spécifiques ont été mises en œuvre, basées sur un travail bibliographique conséquent, associé à des mesures et des expertises très spécifiques. La méthodologie présentée ici a consisté en une première étape de recensement des données de site et bibliographiques sur les impacts de projets pouvant comporter des similitudes, afin de hiérarchiser le besoin en études complémentaires qui ont été menées par la suite : impacts acoustiques, impacts des remontées d'eau profonde, impacts du biofouling, etc. Certains de ces sujets font à présent l'objet de programmes de recherche scientifique lancés à l'issue de cette étude

How a collaborative integrated taxonomic effort has trained new spongiologists and improved knowledge of Martinique Island (French Antilles, eastern Caribbean Sea) marine biodiversity.

Although sponges are important components of benthic ecosystems of the Caribbean Sea, their diversity remained poorly investigated in the Lesser Antilles. By organizing a training course in Martinique, we wanted both to promote taxonomy and to provide a first inventory of the sponge diversity on this island. The course was like a naturalist expedition, with a field laboratory and a classroom nearby. Early-career scientists and environmental managers were trained in sponge taxonomy. We gathered unpublished data and conducted an inventory at 13 coastal sites. We explored only shallow water habitats (0-30 m), such as mangroves, reefs or rocky bottoms and underwater caves. According to this study, the sponge fauna of Martinique is currently represented by a minimum of 191 species, 134 of which we could assign species names. One third of the remaining non-identified sponge species we consider to be new to science. Martinique appears very remarkable because of its littoral marine fauna harboring sponge aggregations with high biomass and species diversity dominating over coral species. In mangroves, sponges cover about 10% of the surface of subtidal roots. Several submarine caves are true reservoirs of hidden and insufficiently described sponge diversity. Thanks to this new collaborative effort, the Eastern Caribbean has gained a significant increase of knowledge, with sponge diversity of this area potentially representing 40% of the total in the Caribbean Sea. We thus demonstrated the importance of developing exploratory and educational research in areas historically devoid of biodiversity inventories and systematics studies. Finally, we believe in the necessity to consider not only the number of species but their distribution in space to evaluate their putative contribution to ecosystem services and our willingness to preserve them

New sponge species from Martinique which are currently under description.

<p>New sponge species from Martinique which are currently under description.</p

List of the students and young researchers who attended the Sponge Training Course in December 2013.

<p>FR France, BR, Brazil, CO, Colombia, IN, India, ME, Mexico, PE, Peru, PL, Poland, PR, Puerto Rico, RU, Russia, UK, United Kingdom,. PRO = professional, EDU = education, EX = private environmental expertise / consulting, SC = Scientist, AP = Assistant Professor, RA = Research Associate, RC = Researcher, GR = Graduate student, MS = Master’s student, PhD = Phd student, PDoc = Post-doctoral fellow, TECH = technician or engineer, MPA = Marine Protected Area. S+: previous experience with sponges; S-: no experience, beginner working with sponges.</p

Participants of the Sponge Training Course of Martinique, December 2013.

<p>Top, from left to right, S. Griffits, T. Pérez, J. Vacelet, M. Brassy, G. Tollu, E. García, C. Lejeusne, N. Boury-Esnault, M. Klautau, P. Chevaldonné, S. Chenesseau, S. Zea, C. Díaz, J. Chalifour, A. Ereskovsky, E. Tregarot, D. Tokina, E. Hajdu, R.W. Thacker, S. Pomponi, G. Lobo-Hajdu, L. Babarit, A. Pouget-Cuvelier. Bottom, from left to right, B. Cóndor-Luján, H. Fortunato, P. Leocorny, T. Immanuel, C. Ruiz, F. Azevedo, Ph. (Filipo) Thélamon, J. Massei, Z. Hoffman, J. Garcia-Hernandez, M. Łukowiak, A. Sokolova, P-Y. Pascal.</p

<i>In situ</i> photographs of the sponge community growing on mangrove roots in Martinique.

<p>A) <i>Tedania ignis</i> (the fire sponge) and <i>Haliclona caerulea</i> both exposed at low tide. B) Submerged specimen of <i>Haliclona caerulea</i>, above a mussel aggregate, and the air exposed zone of the red-mangrove root. C) Green algae (<i>Caulerpa</i> sp.), <i>Haliclona caerulea</i> and patches of <i>Tedania ignis</i>. D) Large root covered by algae, except areas where <i>Spirastrella mollis</i> and patches of <i>Tedania ignis</i> are seen. Picture A by C. Díaz and pictures B,C,D by T. Pérez.</p

Distribution of the studied sites.

<p>C = Cave (dark, semi-dark caves, tunnels, overhangs), M = Mangrove, R = Reef (hard bottoms in general, including coral reefs).</p

Taxonomic distribution of Martinique sponge diversity.

<p>Taxonomic distribution of Martinique sponge diversity.</p

<i>In situ</i> photographs of reef and rocky bottoms in Martinique.

<p>A) Shallow rocky habitat where tubes of yellow <i>Aplysina fistularis</i>, large solid <i>Agelas</i> species, and patches of <i>Halisarca caerulea</i> mingle between the <i>Sargassum</i> sp. algae and the coral rubble. B) Massive sponge aggregations with at least six large sponge species (one large tube of <i>Callyspongia plicifera</i>, clumps of <i>Iotrochota birotulata</i>, <i>Agelas</i> spp., <i>Aiolochroia crassa</i>, <i>Myrmekioderma rea</i>, <i>Amphimedon compressa</i>), and stalk crinoids. C) The largest reef sponges the barrel sponge <i>Xestospongia muta</i> aggregates a large diversity of erect and repent species of <i>Callyspongia</i>, <i>Niphates</i>, <i>Amphimedon</i> and <i>Iotrochota</i>, massive <i>Aiolochroia</i> and <i>Mycale</i>, and thin crusts of <i>Spirastrella</i>. D) Extremely large tube clumps of <i>Callyspongia plicifera</i> reside among the varied set of tubular, rods, and massive shaped sponges that aggregate with polychaete worms, algae, and crinoids. All pictures by T. Pérez.</p

<i>In situ</i> photographs of cave community in Martinique.

<p>A) A participant of the Sponge Training Course at the entrance of the Diamond Rock Tunnel; B) This semi-dark community dominated by sponges, with the new spherical <i>Aiolochroia</i> (white arrow); C) With reduced light, the species diversity decreases, but sponges, especially Homoscleromorpha (white arrows), are still dominant (Diamond Rock tunnel); D) In dark conditions, most sponge species are encrusting forms, such as the new <i>Plakina arletensis</i> (white arrow), but in some places big specimens of the lithistid <i>Aciculites</i> sp. (yellow arrow) can be found (Grotte Chauve-Souris, Anses d’Arlet). All pictures by T. Pérez.</p