Vulnérabilité des ressources halieutiques et aquacoles du Pacifique tropical face au changement climatique : résumé à l'intention des Etats et Territoires insulaires océaniens

En complément de l'ouvrage intitulé "Vulnerability of tropical Pacific fisheries and aquaculture to climate change", qui analyse de manière exhaustive les effets possibles du changement climatique sur les plans visant à maximiser les avantages économiques et sociaux tirés de la pêche et de l'aquaculture en Océanie, le présent document fait la synthèse des conclusions de cette évaluation de la vulnérabilité climatique régionale en ce qui concerne les Territoires français du Pacifique. Les mesures d'adaptation, les politiques et les investissements préconisés devraient permettre à chaque Territoire de réduire les menaces que fait peser le changement climatique sur la pêche et l'aquaculture, tout en tirant le meilleur parti des débouchés qui en découlent. Les recommandations formulées répondent directement aux préoccupations de toutes les parties prenantes et de leurs partenaires dans le développement. (Résumé d'auteur

Vulnerability of tropical Pacific fisheries and aquaculture to climate change : summary for Pacific island countries and territories

The purpose of this summary is to present the main results from the regional vulnerability assessment as they apply to each country and territory, making the information easily to use. The practical adaptations, policies and investments described here are needed to maintain the economic and social benefits of fisheries and aquaculture in the face of climate change. They are essential planning tools

Hydrography and Jack mackerel stock in the South Pacific - Final report

This study aims (i) to identify the most likely population structure hypotheses of Jack mackerel, (ii) to identify management objectives for Jack mackerel, and (iii) to evaluate sustainable management strategies to achieve these objectives. These three elements were considered through literature review, statistical and population dynamics modelling. Two different conclusions were drawn: a conclusion towards most likely population structure and a conclusion towards most likely stock structure

KRILLPODYM: a mechanistic, spatially resolved model of Antarctic krill distribution and abundance

Robust prediction of population responses to changing environments requires the integration of factors controlling population dynamics with processes affecting distribution. This is true everywhere but especially in polar pelagic environments. Biological cycles for many polar species are synchronised to extreme seasonality, while their distributions may be influenced by both the prevailing oceanic circulation and sea-ice distribution. Antarctic krill (krill, Euphausia superba) is one such species exhibiting a complex life history that is finely tuned to the extreme seasonality of the Southern Ocean. Dependencies on the timing of optimal seasonal conditions have led to concerns over the effects of future climate on krill’s population status, particularly given the species’ important role within Southern Ocean ecosystems. Under a changing climate, established correlations between environment and species may breakdown. Developing the capacity for predicting krill responses to climate change therefore requires methods that can explicitly consider the interplay between life history, biological conditions, and transport. The Spatial Ecosystem And Population Dynamics Model (SEAPODYM) is one such framework that integrates population and general circulation modelling to simulate the spatial dynamics of key organisms. Here, we describe a modification to SEAPODYM, creating a novel model – KRILLPODYM – that generates spatially resolved estimates of krill biomass and demographics. This new model consists of three major components: (1) an age-structured population consisting of five key life stages, each with multiple age classes, which undergo age-dependent growth and mortality, (2) six key habitats that mediate the production of larvae and life stage survival, and (3) spatial dynamics driven by both the underlying circulation of ocean currents and advection of sea-ice. We present the first results of KRILLPODYM, using published deterministic functions of population processes and habitat suitability rules. Initialising from a non-informative uniform density across the Southern Ocean our model independently develops a circumpolar population distribution of krill that approximates observations. The model framework lends itself to applied experiments aimed at resolving key population parameters, life-stage specific habitat requirements, and dominant transport regimes, ultimately informing sustainable fishery management

Integrated Management and Visualization of Electronic Tag Data with Tagbase

Electronic tags have been used widely for more than a decade in studies of diverse marine species. However, despite significant investment in tagging programs and hardware, data management aspects have received insufficient attention, leaving researchers without a comprehensive toolset to manage their data easily. The growing volume of these data holdings, the large diversity of tag types and data formats, and the general lack of data management resources are not only complicating integration and synthesis of electronic tagging data in support of resource management applications but potentially threatening the integrity and longer-term access to these valuable datasets. To address this critical gap, Tagbase has been developed as a well-rounded, yet accessible data management solution for electronic tagging applications. It is based on a unified relational model that accommodates a suite of manufacturer tag data formats in addition to deployment metadata and reprocessed geopositions. Tagbase includes an integrated set of tools for importing tag datasets into the system effortlessly, and provides reporting utilities to interactively view standard outputs in graphical and tabular form. Data from the system can also be easily exported or dynamically coupled to GIS and other analysis packages. Tagbase is scalable and has been ported to a range of database management systems to support the needs of the tagging community, from individual investigators to large scale tagging programs. Tagbase represents a mature initiative with users at several institutions involved in marine electronic tagging research

Interaction between Coastal and Oceanic Ecosystems of the Western and Central Pacific Ocean through Predator-Prey Relationship Studies

The Western and Central Pacific Ocean sustains the highest tuna production in the world. This province is also characterized by many islands and a complex bathymetry that induces specific current circulation patterns with the potential to create a high degree of interaction between coastal and oceanic ecosystems. Based on a large dataset of oceanic predator stomach contents, our study used generalized linear models to explore the coastal-oceanic system interaction by analyzing predator-prey relationship. We show that reef organisms are a frequent prey of oceanic predators. Predator species such as albacore (Thunnus alalunga) and yellowfin tuna (Thunnus albacares) frequently consume reef prey with higher probability of consumption closer to land and in the western part of the Pacific Ocean. For surface-caught-predators consuming reef prey, this prey type represents about one third of the diet of predators smaller than 50 cm. The proportion decreases with increasing fish size. For predators caught at depth and consuming reef prey, the proportion varies with predator species but generally represents less than 10%. The annual consumption of reef prey by the yellowfin tuna population was estimated at 0.8±0.40CV million tonnes or 2.17×1012±0.40CV individuals. This represents 6.1%±0.17CV in weight of their diet. Our analyses identify some of the patterns of coastal-oceanic ecosystem interactions at a large scale and provides an estimate of annual consumption of reef prey by oceanic predators