“Coral reefs at risk of extinction: “Few areas protected by UNESCO and insufficient research as the waters overheat”
According to Status of Coral Reefs of the World, the sixth annual report by scientists and activists of the Global Coral Reef Monitoring Network (Gcrmn) reaching the conventional threshold of 1.5 degrees Celsius will result in losses between 70 and 98% of coral systems. Higher increases could lead to even worse consequences.
Coral reefs are at risk of disappearing. The alarm was raised by Status of Coral Reefs of the World, the sixth annual report by scientists and activists from the Global Coral Reef Monitoring Network (Gcrmn).
From 2009 to 2018, due to the rising temperatures of the oceans, 14% of corals have already been destroyed, in natural paradises such as the Caribbean Sea, the Red Sea and the Gulf of Aden. An area of 11,700 square kilometers, equal to the largest coral system in the world, the Australian one. The most obvious effect is bleaching, that is, the expulsion of algae under stress, which allows the corals to capture sunlight and take on their characteristic colors.
The greatest losses will concern the next few years: in 2018 the IPCC (Intergovernamental Panel on climate change) estimated them between 70 and 90%, when the planet will reach the limit threshold – definitively ratified at the G20 in Rome – of 1.5 degrees Celsius. Coral reefs occupy 0.2% of the planet’s surface, but provide shelter and nourishment for about 25% of marine species. They also support fishing, tourism and food security in 100 countries.
Since 1998, Gcrmn estimates, this fragile ecosystem has been in crisis. After twenty years of stability, from 1978 onwards, the subsequent observations of the Network, which totaled 2 million in about 1,200 places and 73 countries, revealed a change: a violent increase in water temperatures of about 0.5 degrees has wiped out 8% of living coral at the turn of the millennium.
Until 2010, the emergency seemed to be over: temperatures in the seas had dropped again and the population was returning to previous levels. But the new corals, “just like weeds that grow after a fire, were often more vulnerable to disease, heat and storms,” researcher David Souter, who coordinates the GCRMN, told Yale 360.
According to a study by Lisa Boström-Einarsson of James Cook University in Australia, the 362 projects currently underway are expensive and involve only 56 states. Their duration is then limited to 18 months on small areas of 100 square meters. The cultivation of corals in nurseries and their restoration is very slow and complex. Conversely, allowing a 2-degree increase in global temperatures would quickly lead to the loss of 99% of marine ecosystems.
The greatest safeguards must therefore come from the institutions: “At COP 26 in Glasgow and at the conference on biodiversity in Kunming – commented Inger Andersen, executive director of the United Nations Environment Program (Unep) – governors can save our barriers coral, but only if they are willing to take courageous steps. We must not let future generations inherit a coral-free world ”.
Thus, in the early 2000s the hard corals were double (about 30% of the entire ecosystem) compared to the vegetal carpet under the reef (15%). In a short time, however, the ratio gradually thinned: in 2009 it dropped to 1.5. And the progressive increase of the expelled microalgae, of about 20%, still signals the poor state of health of the corals.
The most significant damages are those in the Pacific, where more than a quarter of the total coral population is found, in the Caribbean and in Australia, where the protection of the Great Barrier Reef is at the center of a bitter tug-of-war between the Scott government. Morrison and Unesco.
The situation is also critical for the Coral reefs of the Red Sea, more tolerant to heat, but compromised by pollution and waste from sewers, the construction industry and agriculture. Another major stressor is intensive tourism: the area hosts around 13 million visitors annually, 65 percent of all who enter Egypt, according to Reuters.
These not only damage the ecosystem, but also contribute to whitening with the use of sun creams. This was revealed in a 2018 article by Cinzia Corinaldesi, professor of ecology at the Polytechnic University of Marche. The zinc oxide nanoparticles “at low depths hinder the exchange of water – she explained to the Middle East Eye – When snorkelers swim, the cream released can affect the corals”. Environmental engineer Hamidreza Sharifan has also found the same phenomenon in the Atlantic, Pacific, Indian Oceans and in the Gulf of Mexico.
The only system that goes against the trend, according to the report, is the East Asian triangle: with 600 different species, it is home to a third of coral reefs globally and is the only reef that has been expanding since the 1980s. “Perhaps the diversity has provided some protection from warming,” said David Souter, “while a healthy population of herbivorous fish and sea urchins keeps algae at bay.”
However, this is a unique case and even the positive signs such as the 2% increase in corals in 2019 are too timid and too few to balance the losses and respect the 2030 Agenda for sustainable development. We need to expand the list of areas under UNESCO protection and focus more decisively on research.