Mapping the stress exposure acting on the world’s coral has identified the reefs most at risk of bleaching due to climate change and also the human communities that might be reinforcing their decline.
A large team of researchers led by experts at the World Conservation Society has grouped coral reef systems into clusters based on their stress exposure. The study worked on a clear recognition of two separate types of stress: one global radiation stress from human induced climate change and the other reinforcing stress exterted by complimentary local activities.
Coral thrive best in ocean environments low in plant life and rich in oxygen- a condition termed as oligotrophy. Dominating human presence and activity on coastlands often entails rising levels of land runoffs that make it impossible for such an environment to exist. Such human intervention combined with more direct disturbances like fishing speed-up the damaging impact of overall global warming. These disturbances, seen mainly in areas with high river runoff and sedimentation, however, are controllable by mitigating human impacts through conservation management.
The authors of the new study reason: “Because coral bleaching and mortality is driven by factors such as temperature and their interactions with other stressors like pollution and sedimentation, it may be possible to prevent some damage by reducing the impact of stressors that are not related to climate change.”
Local factors like these are exerting “high” level of reinforcing stress in the waters of the Gulf of Kutch and northern Gujarat, where moderate levels of uncontrollable radiation stress are already in play. Coral in the central parts of the Indian Ocean are exposed to high radiation stress but low reinforcing stress “with the exception of reefs in Sri Lanka and India.” Western regions of the Indian Ocean are exposed to high overall stress but also include some reefs that are least exposed to the overall stress.