Tag Archives: mediteraneean

Corals in the Mediterranean are becoming ‘functionally extinct’ due to climate change

Climate change is affecting corals everywhere — including in the Mediterranean, according to a new study.

Paramuricea clavata. Image via Wikimedia.

Coral populations in the Mediterranean are experiencing immense damage due to climate-change-induced heatwaves. Two emblematic species, the red gorgonian (Paramuricea clavata) and the red coral (Corallium rubrum), have lost 80 to 90% of their total biomass since 2003, according to new research.

The findings are very concerning. Coral populations are a linchpin of the marine ecosystems they belong to, providing food and shelter for a multitude of other species. The incredible decline seen in this paper is likely indicative of the broader coral communities in the Mediterranean. If so, wildlife in the sea could be in a much more dire situation than anyone believed.

A sea of troubles

“We observed an average biomass loss regarding the initial biomass of 80% in populations of red gorgonian, and up to a 93% regarding the studied population of red coral,” notes Daniel Gómez, a researcher at the Institute of Marine Sciences of Barcelona (ICM-CSIC) and lead author of the study.

“These data are worrying for the conservation of these emblematic species, and it indicates that the effects of the climate crisis are speeding up with obvious consequences for the submarine landscapes, where the loss of coral equals the loss of trees in forests,” notes Joaquim Garrabou, also member of ICM-CSIC.

The authors explain that populations of the two studied coral species could be unable to recover under current conditions. Their plight comes down to rising temperatures, but especially to significant heatwaves that have impacted the region repeatedly, with the first one occurring in 2003.

Water temperatures are reaching levels that are completely unbearable for these corals and maintaining those temperatures for days, even weeks at a time, the authors explain. While corals all over the world are affected, this is the first study to quantify the effects of climate change and heatwaves on Mediterranean corals in particular. Here, as in other areas, climate change is causing mass mortality in the sea’s coastal ecosystems.

Both species are emblematic of the Mediterranean, underpinning the area’s complex ecosystems. They also have a large role to play in shaping the sea’s distinctive landscapes and look.

Researchers currently have information on the short-term response of corals to marine heatwaves. That being said, corals are long-lived creatures with very slow population dynamics — they are slow to grow and slow to spawn new generations) — so accurately understanding their response to climate change required decades of study. And that’s what the team did.

They used data from a long-term project by the MedRecover research group, which monitored different populations of coral in the protected marine area of Scandola (in Corsega, France) which saw mass mortality after the 2003 heatwave. Of particular interest were population density, size structure, and total biomass, which were used as proxies to estimate the overall health of these coral communities. Data was collected for fifteen years following the heatwave (up to 2018).

The data showed that all populations monitored in the study hadn’t recovered following the heatwave. In fact, they tended to collapse. Today, they are functionally extinct, the team explains.

“We believe one of the main reasons why we observed these collapse trajectories is the potential recurrent exposure to heatwaves [in 2009, 2016, 2017, 2018], incompatible with the slow populational dynamics of these species,” says Cristina Linares, professor at the Department of Evolutionary Biology, Ecology and Environmental Sciences of the Faculty of Biology and member of IRBio, co-author of the paper.

“During these heatwaves, the temperature conditions in the studied area reached extreme levels which are incompatible with the life of these corals, which probably caused new mortality events to the decimated populations and made the recovery impossible.”

These populations are at serious risk of actual extinction, especially since the number and intensity of marine heatwaves is set to increase in the future as the climate crisis deepens. However, the team adds that there are likely some areas in the Mediterranean where the impacts of climate change may be lower due to local factors. These should act as ‘climate refuges’ to help preserve the corals, they conclude.

The team “Population collapse of habitat-forming species in the Mediterranean: a long-term study of gorgonian populations affected by recurrent marine heatwaves” has been published in the journal Proceedings of the Royal Society B: Biological Sciences.

Oil spill from Syria is close to hitting Cyprus’ shores

An oil leak from Syria’s largest refinery is spreading across the Mediterranean Sea and could reach Cyprus by Wednesday, according to authorities on the island. Satellite imagery confirmed that this spill is larger than initially thought, currently covering around 800 square kilometers (309 square miles).

The coast of Cyrpus. Image credits Dimitris Vetsikas.

Authorities on the island of Cyprus say the oil spill could reach their shores by Wednesday. The spill was first reported on August 23, originating near a thermal power plant in the city of Baniyas. Syrian authorities have not been able to contain the spill so far.

Oil trouble

Authorities in Turkish Cyprus have already taken emergency action to try and keep the crude away from the island’s beaches and from wreaking environmental havoc. Teams with sponges and hoses have been deployed on-site to try and mop up some of the oil. Turkey also plans to dispatch two ships to the island and assist in clean-up and containment efforts, and the Greek Cypriot government is collaborating with the European Maritime Safety Agency to get an oil recovery vessel, as well.

In the meantime, a 400-meter long barrier has been erected off of the Karpas peninsula to prevent oil from contaminating local beaches.

The spill is currently covering an area of around 800 square kilometers (309 square miles). Simulations run by the Cypriot Department of Fisheries and Marine Research suggest that the oil spill could reach the Apostolos Andreas Cape, Cyprus’ northernmost point, within a day, according to CNN. This statement was made at around 11 a.m. local time (4 a.m. ET) on Tuesday, and at the time the oil slick came within 7 kilometers (4 miles) of the coast.

The Guardian, citing “environmental officials in Turkish-occupied northern Cyprus – internationally recognized only by Ankara”, report that roughly 20,000 tons of fuel oil have been spilled from the Syrian plant so far.

“We are taking the necessary measures by mobilizing our resources to stop any chances of the spill turning into an environmental disaster,” Turkish Vice President Fuat Oktay told the state-run Anadolu news agency.

Hopefully, everyone will be banding together and doing their utmost best to tackle this spill. The Mediterranean is a wonderful place, and it has already suffered through an oil spill earlier this year, in February, from the coast of Israel. Politically speaking, the actors that have to work together to work this out don’t really have much love for one another. Still, everybody has a lot to lose if they don’t put their differences aside, as the Mediterranean is an important economic sea and a wildly diverse ecosystem.