Negative impacts that are already obvious in this region include coral bleaching (damaging critical fish habitat), increasing intensity of storms together with increased sea-level rise (damaging fish habitats, fishery access and assets), and sargassum influxes (disrupting fishing operations and communities and impacting the sustainability of the resource).
Of the major wild capture fishery types, those associated with shallow, nearshore environments are probably most vulnerable to climate change. Loss of coral reef habitats, and to a lesser extent, mangrove wetlands and seagrass meadows, coupled with over-exploitation of stocks, are the most important factors.
Fisherfolk and coastal communities are being seriously affected by changes to the fish and shellfish populations they depend upon, and directly by the effects of storms on fishing activities. Recent influxes of sargassum have affected the harvest sector and fishing communities. Whilst some species can benefit from the increased shelter they provide, they can limit access to fishing grounds, blocking vessel movement in ports, interfere with fishing gear, and damage vessel motors.
In Montserrat, tropical storms and hurricanes experienced in recent decades have been shown to have a major impact on fisheries. Hurricane Hugo caused $2M USD damage to the fishery sector in 1989, with similar losses in 1995, 1998, 1999, 2010 and 2017. In Anguilla, major impacts from storms and hurricanes have been reported in recent decades, damaging critical infrastructure and leading to long recovery times for parts of sector (e.g., due to port damage).
Low evidence, medium agreement
In terms of what is already happening, there is medium/high level agreement based on the very few fisheries studies published for this region, supported by impacts reported in other similar, tropical fisheries. There are also significant difficulties separating climate change effects from other human pressures.
Further impacts are predicted from temperature rise, ocean acidification, changing currents and a decrease in oxygen, most notably in near shore environments.
A rise in sea surface temperature (SST) is expected to cause more frequent and severe coral bleaching events in the region, damaging and reducing habitats for reef fish. Increase in SST is also expected to affect fish and shellfish directly, by impacting growth, reproduction, and survival, and causing geographical shifts in species at their thermal limits. Changes in pH (ocean acidification) are projected to affect shellfish in particular, impacting yields of the most valuable species. Coral reefs will be impacted further by reduced pH, with major knock-on effects for the biodiversity and fisheries they support.
Many of the OTs rely on shallow reef-associated fisheries, which are already severely degraded and likely to be hit hardest in the future. Effects on high-value species (e.g., spiny lobster, conch, and snapper) could mean that catch rates decrease, in turn affecting export trade and local markets. Deeper-living oceanic species are likely to remain less vulnerable to climate change impacts at present, although, changes in productivity and distribution could force fishers to retool, fish for longer hours, or travel further to maintain catch rates.
The impact of elevated temperatures is clearly demonstrated in the Cayman Islands, home to some of the largest remaining spawning aggregations for the culturally and economically important Nassau Grouper. Preliminary research suggests that rising water temperature will impact larval success and potentially lead to recruitment failure. Projected increases in sea temperatures over the next 20-50 years may have devastating consequences for fisheries in the Cayman Islands.
An increase in high-intensity hurricanes in the region will impact safety at sea and cause more frequent damage to coastal communities as well as to gear, vessels, and infrastructure, causing long recovery times for the fishing sector.
In the future, aquaculture is expected to become more important in the region. Whilst there is little information on climate change effects, higher future temperatures may initially result in higher growth rates. However, if temperatures increase beyond species’ tolerance limits, some current sites or species used in this region for aquaculture may become less suitable in the future.
Low evidence, low agreement
In terms of what could happen in the future, there is a low level of agreement, based on the absence of research and tangible evidence for these territories. Future projections are complicated by an absence of knowledge regarding synergistic effects of multiple climate change (and other) stressors and external market forces and demographic changes.