Impacts of climate variability on the tuna economy of Seychelles

Many small island states have developed economies that are strongly dependent on tuna fisheries. Consequently, they are vulnerable to the socio-economic effects of climate change and variability, processes that are known to impact upon tuna fisheries distribution and productivity. The aim of this study was to assess the impacts of climate oscillations on the tuna-dependent economy of Seychelles. Using a multiplier approach, the direct, indirect and induced economic effects of the tuna industry declined by 58%, 34% and 60%, respectively, in 1998, the year of a strong warming event in the western Indian Ocean. Patterns in tuna purse seine vessel expenditures in port were substantially modified by strong climate oscillations. A cointegration time-series model predicted that a 40% decline in tuna landings and transhipment in Port Victoria, a value commensurate with that observed in 1998, would result in a 34% loss for the local economy. Of several indices tested, the Indian Oscillation Index was the best at predicting the probability of entering a regime of low landings and transhipment. In 2007, a moderate climate anomaly was compounded by prior overfishing to produce a stronger that expected impact on the fishery and economy of Seychelles. The effects of fishing and climate variability on tuna stocks are complex and pose significant challenges for fisheries management and the economic development of countries in the Indian Ocean

Impacts of climate variability on the tuna economy of Seychelles

Many small island states have developed economies that are strongly dependent on tuna fisheries. Consequently, they are vulnerable to the socio-economic effects of climate change and variability, processes that are known to impact upon tuna fisheries distribution and productivity. The aim of this study was to assess the impacts of climate oscillations on the tuna-dependent economy of Seychelles. Using a multiplier approach, the direct, indirect and induced economic effects of the tuna industry declined by 58%, 34% and 60%, respectively, in 1998, the year of a strong warming event in the western Indian Ocean. Patterns in tuna purse seine vessel expenditures in port were substantially modified by strong climate oscillations. A cointegration time-series model predicted that a 40% decline in tuna landings and transhipment in Port Victoria, a value commensurate with that observed in 1998, would result in a 34% loss for the local economy. Of several indices tested, the Indian Oscillation Index was the best at predicting the probability of entering a regime of low landings and transhipment. In 2007, a moderate climate anomaly was compounded by prior overfishing to produce a stronger that expected impact on the fishery and economy of Seychelles. The effects of fishing and climate variability on tuna stocks are complex and pose significant challenges for fisheries management and the economic development of countries in the Indian Ocean.

Energy consumption and pollution prevention policy related to marine activities

La thèse porte sur la consommation d'énergie et les politiques de prévention des pollutions liées à cette consommation dans les activités maritimes. Dans le cadre général de la politique Marpol, l’Organisation Maritime Internationale (OMI) a défini une forte réduction de la teneur en soufre des carburants utilisés dans ce secteur, depuis 2015 dans les zones « SECA » et à l’horizon 2020-2025 dans les autres zones maritimes. Pour leurs besoins énergétiques, les flottilles de pêche sont actuellement dépendantes des produits pétroliers dont les prix sont très fluctuants. Nous menons une analyse économétrique sur la transmission des prix entre le pétrole et le poisson. Nous étudions les alternatives énergétiques permettant de réduire la dépendance aux produits pétroliers, biocarburant, GNL et hydrogène. Nous effectuons une analyse technicoéconomique du développement du GNL. Nous construisons un modèle de simulation pour analyser la rentabilité de ce type d’investissement en situation d’incertitude sur les prix du pétrole. Finalement, nous menons une analyse de la dynamique entre débarquements de thonidés et consommation de carburant dans l’Océan Indien avec un modèle de chaîne de Markov à changement de régime. Nous mettons en évidence un effet d’un indice climatique sur cette relation entre débarquements de poisson et consommation d’énergie.The thesis focuses on energy consumption and pollution prevention policies related to this consumption in maritime activities. In the framework of Marpol policy, the International Maritime Organization (IMO ) has established a strong reduction for the sulfur content of fuels used in this sector since 2015 in " SECA " zone and by 2020-2025 in other sea areas. For their energy needs, fishing fleets are currently dependent on petroleum products whose prices are very volatile. We conduct an econometric analysis of price transmission between oil and fish. We study energy alternatives that reduce dependence on petroleum products as biofuel, LNG and hydrogen. We conduct a technical and economic analysis of LNG development. We build a simulation model to analyse the profitability of this type of investment under uncertainty about oil prices. Finally, we conduct an analysis of the dynamics between tuna landings and fuel consumption in the Indian Ocean with a Markov chain model for regime change. We highlight the effect of climate index on the relationship between fish landings and energ

Transmission des prix entre les marchés de l'énergie et du poisson : est-ce que les cours du pétrole représentent de bons prédicteurs des prix du thon ?

International audienceBecause most food processes are fossil fuel-based, many food markets are more or less connected to the oil market. Fishing technology in the high seas being energy-intensive, higher oil prices should affect the fish markets. This research looks at price transmission between Marine Diesel Oil and a global fishery commodity, frozen Skipjack tuna (Katsuwonus pelamis) through a time series analysis combining four different methods to look for possible structural breaks and regime shifts in the relationship (Bai-Perron, Lavielle, Gregory-Hansen, Markov-switching). Our results prove that the long-run equilibrium between both prices is weakening after the turn of the 2010s. Explaining the drivers of change is of great interest for short-term forecast but also to build long-term scenarios where both supply and demand variables are likely to affect tuna markets.Puisque la plupart des filières agro-alimentaires reposent sur des énergies fossiles, de nombreux marchés alimentaires sont plus ou moins connectés au marché du pétrole. La technologie des pêcheries hauturières étant elle-même intensive en énergie, un prix plus élevé du pétrole devrait se refléter dans le prix du poisson. Cette recherche s'intéresse à la transmission des prix entre le diesel marin et un produit de la pêche global, le listao (Katsuwonus pelamis) congelé, via une analyse de séries temporelles croisant quatre méthodes différentes pour repérer des changements structurels et de régime dans la relation de prix (Bai-Perron, Lavielle, Gregory-Hansen, Markov-switching). Nos résultats montrent que l'équilibre de long terme s'atténue au tournant des années 2010. Expliquer les facteurs de ce changement représente certes un enjeu important pour des prévisions de court-terme, mais permet également de bâtir des scénarios de long-terme où les variables d'offre et de demande sont susceptibles de perturber conjointement les marchés thoniers