In the early 1990s, Thureya Mohamed would smile all the way to her house in Wasini island, Kwale county. She was always assured of enough fish for her family. Those days, the coral reefs were healthy.

 

Then things changed. Mass bleaching occurred in 1998, 2010 and 2016. This occurs when corals are stressed by changes in conditions such as temperature, light or nutrients. They expel the symbiotic algae living in their tissues, causing them to turn completely white.

Experts blame this on climate change and human activities, such as dumping of waste, mangrove cutting and sedimentation.

Healthy corals provide shelter for many species of tropical animals that rely on the structure provided by corals for their homes, and others find food that shelters in the crevices of stony corals. Coral degradation, therefore, has consequences for those like Thureya who rely on fishing.

Before the bleaching, corals along the coastal waters occurred in shades of olive green, brown, tan and pale yellow. The more they bleached, the more fish stocks dwindled.

Thureya, the treasurer of Wasini Beach Management Unit, said while poor fishing methods and gears also hurt supply, destruction of corals was the biggest problem. "We had to move in and reverse the trend," she said, referring to a community initiative in conjunction with the Coast Development Authority.

The mother of five said locals were concerned there would be mass die-off of coral reefs, spelling doom on the fishing sector. Scientists have already warned that the die-off could happen as soon as 2040.

One such scientist is Cody Clements, a Postdoctoral Fellow, Georgia Institute of Technology. Clements says coral reefs are home to so many species they often are called the rainforests of the seas.

"Today they face a daunting range of threats, including ocean warming and acidification, overfishing and pollution,” he said, adding that more than one-third of all coral species are at risk of extinction worldwide.

Clements is one of many scientists who are studying corals to find ways of helping them survive and recover.

BIGGEST THREAT

In October last year, an Intergovernmental Panel on Climate Change issued its special report on the impacts of global climate change on nature and society. 

The IPCC report specifically examined the results 

of warming of 1.5°C above pre-industrial levels. This is in the context of the global response to the threat of climate change, sustainable development and efforts to eradicate poverty. 

Of particular concern to the Wasini community after the report was released is the fact that Earth temperatures are still rising.

The IPCC report pointed out that the effects of climate change will not be disbursed uniformly across the globe. The rising temperatures will have a disproportionate impact, hitting the poor hard.

The report said damage to coral reefs has implications for several key regional services. It said coral reefs account for 10 to 12 per cent of the fish caught in tropical countries, and 20 to 25 per cent of the fish caught by developing nations.

This role is threatened by future sea-level rise, the decrease in coral cover, reduced rates of calcification, and higher rates of dissolution and bioerosion due to ocean warming and acidification.