UWI lecturer warns Caribbean fisheries highly vulnerable to climate change

A senior lecturer at the Centre for Resource Management and Environmental Studies at the University of the West Indies is predicting severe negative impacts, including loss and alteration of habitats, smaller and less-diverse fish stocks, and coral bleaching, and urged prompt action to help the region’s fishers prepare.

These views are contained in a recent analysis in the Stockholm Environment Journal by Leonard Nurse, PhD, senior lecturer at the Centre for Resource Management and Environmental Studies at the University of the West Indies and a member of the scientific team of the Inter-governmental Panel on Climate Change.

Fisheries employ nearly 200,000 people in the Caribbean community alone, Nurse noted, earning US$5 billion to US$6 billion per year in foreign exchange and providing about 10 percent of the region’s protein intake.

Recreational fishing and dive tourism are also major revenue sources; in 2000, one study estimated, dive tourism based on coral reefs brought in about US$ 2.1 billion. For Tobago alone, coral reefs drew US$ 43.5 million in 2006, or 15 percent of GDP. Nurse, whose specialty is gauging climate impacts on small island states, said that although there is a ‘dearth of research’ on specific effects of climate change on Caribbean fisheries, broader studies and observations in other regions provide plenty of grounds for concern.

Expected changes

Global climate models suggest that average temperatures in the Caribbean will rise by 0.5– 1.0 ° C by 2039, 0.8– 2.5 ° C from 2040 to 2069, and 0.94– 4.8 ° C between 2070 and 2099, Nurse wrote, and similar trends in sea surface temperatures are expected.

Warming waters are a primary cause of coral bleaching, Nurse noted.

Many Caribbean islands have reported ‘significant’ bleaching, and the problem is expected to become more severe, with negative impacts on the diversity and size of fish communities.

There is also evidence that worldwide, species are moving poleward as sea temperatures rise. Plankton mass has declined in many areas, leaving fish without the food they need. Warming waters and changing ocean circulation patterns may also alter the length and timing of spawning seasons, and could lead to higher fish mortality.

In addition, there is evidence that climate-related changes in ocean chemistry, including acidification, threaten fish. The world’s oceans have become roughly 30 percent more acidic since 1750, Nurse noted, and this makes it harder for organisms to form shells; with global CO2 increasing, this is a grave threat to reef habitats and associated fauna.

Lastly, the severity of tropical storms is increasing, with eight Category Five hurricanes in 2001– 2010, compared with a total of 23 between 1928 and 2000.

Storms are also reaching high intensity more quickly, suggesting that fishers will have less time to secure their boats and gear. More severe storms could also accelerate coastal erosion and put critical infrastructure such as wharves at risk. ‘Thus, apart from having to adapt to altered conditions such as changes in fish stock distribution and abundance, stakeholders will also be confronted by the possibility of increased storminess at sea and on land, and higher risk to the safety of fishers as well as vessels,’ Nurse wrote .

Adaptation is the only option

Since stopping climate change is beyond Caribbean fisheries’ power, and negative effects are already being felt, ‘‘adaptation is the only option’’, Nurse said. Actions must be taken to improve the resilience of habitats and key species, eg, strict enforcement of marine control protocols; reduced contamination from land-based sources; reviving and expanding habitat protection programmes and control of overharvesting and damaging methods of harvest.

Good governance and co-management principles, especially those based on principles of ecosystem health, partnership, equity and sustainable livelihoods, would also be crucial to adaptation planning. Nurse also suggested targeting new or non-traditional species to allow fishers to maintain their livelihoods while relieving pressure on heavily exploited stocks.