CLIMATE CHANGE AND THE FISHERIES IN THE SEYCHELLES
A contribution to enable the Seychelles National Climate Change Committee to prepare its first National Communication to the United Nations Framework Convention for Climate Change (UNFCCC).
Prepared by Rondolph Payet, Jean-Luc le Blanc and Francis Marsac
The Republic of Seychelles comprises of some 100 widely scattered islands extending between 3° to 10° S and 45° to 58° E in the Western Indian Ocean (Figure 1). Total land mass area is approximately 443 Km2. The Exclusive Economic Zone encompasses 1,374,000 km2 of which only 3.5% (48,019 km2) of ocean cover are depths of less than 200 m, the rest is over depths of 1,000-1,500 m. The shallow areas makes up the plateaux and banks.
Fishing is the second most important industry after tourism, contributing towards 4% of the GDP. Around 4,500 tonnes of fish is landed annually by the artisanal fishery which supplies all fish required for domestic consumption whilst around 370 tonnes is exported (value = US $ 2M). The industrial fishery of the Western Indian Ocean landed approximately 270,000 tonnes in 1996. The tuna processing industry generated approximately US$ 35M in 1996. The consumption of fish per capita is one of the highest in the world standing at 80 kg/year. Therefore, the vulnerability of this sector to climate change should be monitored and studied in order to prevent any drastic effects on the economy and social aspects of Seychelles.
Although the effects of environmental variability on fisheries are increasingly being recognised, the contribution of climate change to such variability is not yet clear. Research has been undertaken to study the impact of climate on the tuna fisheries in the Seychelles (Marsac and Le Blanc, 1996), and show some effects of interannual variability on catches of yellowfin tuna that can be linked to the El Niņo/Southern Oscillation (ENSO). This climatic event results from anomalies of sea-level pressure, wind field and sea surface temperature. Currents in the Indian Ocean are influenced to a certain extent by such anomalies, hence variations in the marine biological productivity.
Climate change however, deals with a longer time scale than interannual variations (decades to centuries versus two to five years (figure 2). Though global climate changes are identified with a diminishing uncertainty (global warming, sea-level rise, etc.), regional and local changes in the climate system are not yet predictable through the use of numerical models (GCM). Therefore, most of what can be said on the vulnerability of the fisheries sector towards climate change effects, is still speculative and no quantification of sensitivity will be made here.
Global climatic changes and their associated ocean response will be considered. A review of the fisheries (artisanal, semi- industrial and industrial with more emphasis on artisanal) and regional changes over the Seychelles will be presented and their possible impact on fisheries proposed. Finally, recommendation on future monitoring and observation work is suggested to address the possible adverse effects of climate change on the fisheries sector.