Science and Innovation to monitor and preserve the services of the marine ecosystems
To promote, build and foster sustainable use of Seychelles natural marine resources, through implementing resilience-based management with multi-scale impacts both at local and regional levels.
Contributing to the conservation of Seychelles’ natural marine ecosystem and surrounding ocean through targeted innovative primary and applied research projects, monitoring, development of baseline datasets; advocacy, publications, education and awareness
Working in partnership with government, NGOs, parastatals and private sector to promote sustainable utilization of Seychelles natural marine resources and increasing sustainable livelihood through empowerment of Seychellois
Undertaking environmental and socio-economic research that promotes the acquisition of new knowledge about Seychelles marine environment, its usage and use the research results to improve natural resource management
Promoting reproducible and robust standard protocols and promote data sharing and open source access to information.
Gilberte graduated with a Master’s degree in Oceanography from the University of Rimouski in Québec, Canada where her research focused on the impact of anthropogenic noise on the feeding behaviour of fish larvae. She has over 14 years of experience in biodiversity conservation working for the Seychelles government, whereby she has worked both at a technical and decision making levels. She is presently a Senior Research Scientist at the Seychelles National Parks Authority. Her work focuses mainly on coral reefs and associated habitats as well as marine protected area management. Gilberte cofounded SOS in October 2019.
Nathalie graduated from the University of Western Brittany with a PhD on the contamination of decapod crustaceans and now has more than 15 years’ experience in applied marine ecology, ecosystems and food web monitoring. She worked at the French Research Institute for Development on small pelagic and large migratory fisheries (billfish, tuna) before joining the Seychelles Fishing Authority where her research focused on the biology, trophodynamics and nutritional value of reef and coastal resources. Nathalie cofounded SOS in October 2019 to take a more active part in the restoration and conservation of the marine habitats and resources of the Seychelles Archipelago.
Léo completed a Master’s degree in Oceanography in 2015 in Rimouski, Québec, Canada where he worked on the development and behaviour of American Lobster. As a project leader for Marine Conservation Society Seychelles, he worked on two main projects: 1) the Cerf Island Conservation Program where the goal is to improve the biodiversity around Cerf Island through a participatory partnership with the private sector; 2) a science-based project aimed at restoring commercially important spiny lobster habitat, to help develop a sustainable fishery in collaboration with the University of Seychelles and the Seychelles Fishing Authority. Léo cofounded SOS in October 2019.
ALLEN CORAL ATLAS
Coral reefs are under threat worldwide from numerous environmental and anthropogenic stresses, and effective management and policy formation requires monitoring across all scales from local to global. Remote sensing provides a valuable complementary monitoring approach to manual (visual) survey, in particular at large scales (>10's km2) where manual surveys would be prohibitively expensive and impractical.
The Allen Coral Atlas project is using 2.6 m resolution satellite images to create a global map of coral reefs. Key mapping objectives are the abundance, distribution and health of living flora and fauna, also known as the benthos, and include benthic type (e.g. coral and algae), benthic change detection and coral bleaching.
SOS participates in the project by collecting ground-truth data, i.e. georeferenced-photos of different Seychelles reef habitats, to enable calibration of remote-sensing data and aid in the interpretation and analysis of what is being sensed
KORAY - SEYCHELLES MARINE BENTHIC MONITORING PROGRAM
The Seychelles Marine Benthic Monitoring Program’s main objectives are to produce evidence against which to evaluate the cause and direction of change in the Seychelles marine coastal environment, and to inform which management measures are appropriate and successful. Initiated in 2020 by SOS, the KORAY program relies on annual and seasonal georeferenced-photo surveys of the different benthic habitats around the Seychelles Islands. The spatio-temporal analysis of the benthic cover data through machine learning helps then building Seychelles marine benthic habitat mapping.
TIPTOP - PERSISTENT ORGANIC POLLUTANTS AND MICROPLASTICS IN TUNA
An important and emerging issue for fisheries is the increasing prevalence of Persistent Organic Pollutants (POPs) and microplastics in the global ocean which present increasing physical and toxicological risks to marine organisms with the potential for compromising food security and trade initiatives. TIPTOP project aims to determine the occurrence of POPs and microplastics in South Pacific tunas and assess the risks associated with tuna consumption for the concerned populations. SOS brings its expertise and experience gained from past projects on POP contamination of large pelagic fish conducted in the western Indian Ocean. Results will contribute to a better understanding of the distribution of POPs and microplastics at regional and ocean scales and the bioaccumulation in high order marine predators.
Munschy C, Bély N, Héas-Moisan K, Olivier N, Pollono C, Hollanda S, Bodin N 2020. Tissue-specific bioaccumulation of a wide range of legacy and emerging persistent organic contaminants in swordfish (Xiphias gladius) from Seychelles, Western Indian Ocean. Mar. Pollut. Bull., 158:111436.
Summary: Swordfish (Xiphias gladius) is a major marine resource of high economic value to industrial and artisanal fisheries. As a top predator with a long lifespan, it is prone to accumulate high levels of contaminants. The bioaccumulation of a wide range of both legacy and emerging persistent organic contaminants was investigated in the muscle, liver and gonads of swordfish collected from the Seychelles, western Indian Ocean. The detection of all target contaminants, some at frequencies above 80%, highlights their widespread occurrence, albeit at low levels. Mean concentrations in muscle were 5637, 491 and 331 pg g-1 ww for organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and perfluoroalkyl substances (PFASs), respectively. ∑BFR mean concentrations were far below, i.e. 47 pg g-1 ww. The data are among the first obtained for such a high diversity of contaminants in an oceanic top predator worldwide and constitute a benchmark of the contamination of Indian Ocean ecosystems.
Munschy C, Vigneau E, Bély N, Héas-Moisan K, Olivier N, Pollono C, Hollanda S, Bodin N 2020. Legacy and emerging Persistent Organic Pollutant (POP) levels and profiles in top predator fish from the western Indian Ocean in relation to their trophic ecology. Environ. Res. 188:109761.
Summary: Tuna and billfish are large pelagic fish of ecological importance in open oceans. As top predators with a long lifespan, they are prone to exposure to various contaminants such as persistent organic pollutants (POPs) and contaminants of emerging concern. In this study, three pollutant families were investigated, including polychlorinated biphenyls (PCBs), organochlorinated pesticides (OCPs) and perfluoroalkyl substances (PFASs), including perfluorooctane sulfonate (PFOS) and perfluorocarboxylic acids (PFCAs). Contamination was investigated in individuals from three tropical tuna species, namely bigeye (Thunnus obesus), skipjack (Katsuwonus pelamis) and yellowfin (Thunnus albacares) tunas and the billfish swordfish (Xiphias gladius), collected from various areas of the western Indian Ocean (WIO) in 2013-2014. Contamination levels and profiles were examined in fish muscle, together with biological parameters (fish length / age, sex, lipid content) and ecological tracers (carbon and nitrogen stable isotopes). POP levels were low in all species in comparison to other locations worldwide, revealing a low impact of anthropogenic organic contaminants in the WIO. A predominance of OCPs (especially DDTs) versus PCBs was highlighted in all species; PFASs were predominant over chlorinated POPs in tunas. Among the studied PFASs, long-chain PFCAs were found to prevail over PFOS in all species. Organic contaminant profiles differed across species according to their foraging habitat; swordfish and bigeye tuna, which both feed in deep oceanic layers, showed similarities in their contaminant profiles. Geographically, the distinct DDT profiles of fish from the Mozambique Channel suggested an exposure to different DDT sources, in line with regional use of this insecticide and coupled with an extended residence time of fish in the Channel. To our knowledge, the data presented here are among the first obtained for legacy and emerging organic contaminants in various species of large pelagic predators from the WIO.
Summary: Coral reef ecosystems are among the first to fundamentally change in structure due to climate change, which leads to questioning of whether decades of knowledge regarding reef management is still applicable. Here we assess ecological responses to no-take marine reserves over two decades, spanning a major climate-driven coral bleaching event. Prebleaching reserve responses were consistent with a large literature, with higher coral cover, more species of fish, and greater fish biomass, particularly of upper trophic levels. However, in the 16 years following coral mortality, reserve effects were absent for the reef benthos, and greatly diminished for fish species richness. Positive fish biomass effects persisted, but the groups of fish benefiting from marine reserves profoundly changed, with low trophic level herbivores dominating the responses. These findings highlight that while marine reserves still have important roles on coral reefs in the face of climate change, the species and functional groups they benefit will be substantially altered.
Romanov, E.V., Nikolic, N., Dhurmeea, Z., Bodin, N., Puech, A., Norman, S., Hollanda, S., Bourjea, J., West, W., Potier, M., 2020. Trophic ecology of albacore tuna (Thunnus alalunga) in the western tropical Indian Ocean and adjacent waters. Mar. Freshw. Res.
Summary: In this study we investigated the trophic ecology of albacore tuna in the western Indian Ocean and adjacent Atlantic waters based on stomach content analysis using a reconstituted length and weight of prey approach. From 686 non-empty stomachs collected between 2001 and 2015 across three biogeographic provinces, we describe the diet composition of albacore tuna, analyse its feeding habits and investigate the structure and diversity of mid-trophic-level communities. Epipelagic fish were found to be the principal prey by number and reconstituted weight; cephalopods were the second important prey group. Small organisms prevailed in the diet of albacore tuna, with predation on juvenile fish commonplace. Albacore tuna exhibits a flexible, opportunistic feeding strategy, from ram filter feeding on abundant schooling prey to visual predation on large individuals. Prey species richness varied highly across the region. Oligotrophic conditions within the subtropical gyre of the Indian Ocean generated the most diverse mid-trophic-level communities, with less diverse communities occurring in productive areas. Albacore tuna occupies a similar trophic niche throughout the global ocean, foraging on the same prey families and even species. This study indicates overall temporal stability of the Indian Ocean and south-east Atlantic ecosystems where principal prey species remain unchanged over decades.
Summary: Fatty acids (FAs) are a common tool to investigate trophic ecology due to the transfer of several FAs across trophic levels. However, some dietary FAs are modified to maintain homeostasis. Therefore, for trophic purposes, there is the question of whether to separate lipid fractions into fatty acids that are physiologically regulated (structural, polar lipids) and those which are not (reserve, neutral lipids). This study compared the effect of lipid separation prior to FA analysis (total lipid versus neutral lipid fraction) on the ecological interpretations for several pelagic and benthic marine consumers. A tissue with high total lipid content, the hepatopancreas (total lipid content >17% dry weight), had similar FA proportions (in relative abundance) in both total and neutral lipid fractions. For lean muscle (total lipid content <10% dry weight), differences in FA proportions between lipid fractions were species-specific. Proportions of some FAs can be converted from one fraction to the other using simple linear models (e.g., 22:6n-3 and 18:1n-9 for pelagic consumers) but most differences in FA proportions cannot be corrected which should be considered when comparing data from the literature. The present study should be extended to other species and tissues to urther elucidate the importance of tissue total lipid content and neutral to total lipid ratio on the difference of dietary interpretations between total and neutral FA proportions. In particular, it would be useful for marine trophodynamic studies to define a guideline of the tissue total lipid content above which lipid separation is not required.