By Caty Arévalo
Scientists and conservationists have opened a window of hope to save the most fragile and, at the same time, most vital ecosystems for humans, the coral reefs, showing that strategic conservation plans can save them from the threats that threaten them.
This is evidenced by several reef restoration projects presented at the IUCN World Conservation Congress, which is being held in Hawaii.
“Coral reefs form a barrier off the coast of tropical areas, protecting them from the impact of storms and other extreme phenomena; they house the planet's fish “pantry”; they clean the ocean water and constitute an important source of tourist income, ”Cuban researcher Reinaldo Estrada explained to Efe.
Estimates by the NGO The Nature Conservancy suggest that the services provided by coral reefs provide economic benefits of $ 365 billion a year.
Despite this, the "forests of the seas" -as many experts call them- are considered the most deteriorated ecosystems on the planet due to their high sensitivity to alterations such as the increase in temperature caused by climate change, or ocean acidification. (because every time it has to absorb more CO2 emitted by man).
These factors, along with others such as contamination coming from land, the proliferation of invasive species or overexploitation of fishing (in some cases with techniques as harmful as the use of explosives), have wiped out 27% of the reef area of coral on the planet, and if no action is taken, the percentage will reach 60% in 30 years, according to WWF.
These threats "make the coral sick" -a fascinating mixture of animal and plant organism- "which manifests its ailments by whitening its branches, which, if not stopped in time, causes death," Rold Salm, scientist, told EFE. expert in these ecosystems.
The worst known bleaching episode occurred in September 1998, when the increase in ocean temperature wiped out 16% of the world's reefs; closely followed by the same month of the last two summers (2014 and 2015) where “only conservation for resilience has avoided such catastrophic mortality rates,” Salm stressed.
How is a reef restored?
An example of how preservation plans are the best medicine to “heal” a reef and protect its “immune system” against threats is Kanehone Bay, northeast of Honolulu, Hawaii, on which the reefs fall. foothills of the mighty volcanic mountains made famous by the movie Jurassic Park.
Hank Lynch, one of the ecologists who works in the area, tells Efe that the rains, increasingly torrential, wash everything into the sea and fill the bay with sediment, which, together with the rise in water temperature, has led to the expansion of an invasive alga that was destroying the reef, and affecting the species that live on it (sea turtles, giant mantas, hammerhead sharks or dolphins).
In order to save this jewel of biodiversity, The Nature Conservancy launched an innovative recovery plan in 2012, in which a team of marine biologists submerge several times a week to pluck invasive algae from the reef and collect it in a giant vacuum cleaner. submersible that accumulates them and then deposit them on land.
This technique allows 90% of the harmful algae to be removed (biologists have collected 230 tonnes since they started the project in 2012).
To destroy the remaining 10%, the scientists breed a predatory hedgehog of this type of algae in their laboratories in order to plant it later on the reef and eat the remaining part.
The photographic material resulting from scientific monitoring of the reef during the last four years “shows that its health has improved, and that conservation has made it so strong that it is largely able to recover from the bleaching episodes that occurred in the last two summers. ”Says Lynch.
Something similar occurs in the coral reef of the Ciénaga de Zapata National Park, in Cuba, where the protection of the area, together with strict controls of agricultural activities and the prohibition of fishing have led to a preservation of biodiversity so extraordinary that locals refer to this place as “El Nirvana”.