Dr Anjani Ganase,

Coral Reef Ecologist,

Institute of Marine Affairs.

The pandemic gives us time to pause, to reconsider relationships with people but more importantly, the relationship with the earth and ocean. What should we be doing while our livelihoods, our economies are on pause? How can we make sure our islands can bounce back?

Our history of disturbance

As we celebrate World Oceans Day –June 8 – very little of the marine world remains unaffected by human activities, and this small fraction is rapidly shrinking as climate change becomes more apparent in the most remote areas of the world. Forty-one percent of our marine ecosystems are severely impacted; these consist mostly of nearshore habitats such as coral reefs, mangrove forests, rocky reefs and seagrass beds. The regions of the world where most severe human impacts are observed include the Eastern Caribbean, the North Sea, and the South and East China Sea, all of which have been affected by over-fishing and land-based sources of pollution.

While land-based agricultural runoff is significant in nearshore environment, climate change has the larger geographic span of influence followed closely by commercial fishing. These activities have accelerated over the last fifty to hundred years, and researchers also note that there are cumulative effects. While marine ecosystems go through natural cycles of environmental disturbances (hurricanes, earthquakes etc), the combined constant pressures of human disturbances on top of the natural disturbance events result in many marine ecosystems being pushed beyond a threshold for recovery, as conditions are no longer conducive for survival. These consequences come full circle as the ecosystem losses result in a loss of well-being to the dependent communities.

Ecological resilience

A healthy and resilient ocean is one that is readily able to return to a healthy state following disturbance events or even resist the impact of the disturbance depending on its severity. For example, healthy mangrove forests can effectively reduce the damages of severe storm surge because the thick interconnected root systems stabilise the shore and reduce wave and wind forces. The same root systems create a well-protected refuge for nurseries. Real estate, homes and properties inland are protected by mangrove forests. When healthy forests are damaged, their density might still sustain the habitat and its hydrodynamics as well as provide for regrowth. However, as mangrove forests become more degraded and fragmented, while they may still provide some services, they are less likely to recover from disturbances. Trinidad and Tobago is home to over 93 square-kilometres (just over the size of Anguilla) of mangrove forests that protect and sustain a number of coastal communities and infrastructure.

Similarly, coral reefs can be resilient to disturbances such as global warming and mass bleaching events. Reefs with high biodiversity and functional redundancy of organisms do a better job at recovering from a mass coral die off; but