Journal of the Marine Biological Association of India

Impacts of climate change on marine ecosystems and fisheries

Volume 51 Issue 1

Keith Brander

Abstract

Marine ecosystems have always been affected by natural fluctuations in climate at timescales from decades to millions of years, but since the industrial revolution in the 19th century the increase in greenhouse gases has caused an accelerating rise in global temperature whose effects on marine biota can now be detected. Other human activities (fishing, habitat disturbance, pollution etc.) have also affected marine ecosystems for hundreds of years and climate change interacts with these human-induced pressures. The processes can act at all scales from the physiology of individual organisms to the composition and productivity of ecosystems, with effects on all ecosystem goods and services. The impact of anthropogenic climate change on the natural world and on human activity has become an issue of pressing political and social concern, as the rate of global warming, rising sea level, altered rainfall and falling pH becomes more apparent. Some recent scientific studies of past and current impacts of climate change are reviewed and criteria are proposed to evaluate the credibility of such studies. Improved methods are needed in order to make clear, testable and credible predictions of likely future impacts under different possible climate scenarios. Gaps in our knowledge of impacts of climate on marine ecosystems are identified and proposals are put forward to remedy the gaps. Most of the studies of long term changes and climate impact to date have come from temperate parts of the Atlantic and Pacific and there is a great need for matching information from tropical areas, particularly in the Indian Ocean. A brief overview of trends in world and Indian fisheries is followed by an analysis of some of the major threats arising from climate change and of the kinds of prediction which can be made of future fisheries productivity. Identifying vulnerable countries, fish species and ecosystem can help to allocate resources effectively and deal with critical issues. Finally some proposals for robust, adaptive fisheries management are put forward in order to deal with continuing gaps in data and knowledge, but incorporating new information as it becomes available.

Keywords

Climate change, climate impact, marine ecosystems, fisheries, management

Date : 27-08-2009