The Mediterranean Sea is too warm, and marine biodiversity is suffering

It is a phenomenon that has been going on for decades and has been detailed since 2015 in a study in Global Change Biology. The waves of heat in the Mediterranean Sea are multiplying, reaching a maximum in this summer of 2022, a summer of all records. They arise in particular from terrestrial heat waves, and the two can also maintain each other. They can also come from hot currents which move and bring heat to certain regions.

But what is certain is that global warming amplifies them: all over the world, terrestrial and marine heat waves are more and more frequent, and last longer and longer. “The situation is ‘very worrying'”estimates Joaquim Garrabou in a communicatedresearcher at the Barcelona Institute of Marine Sciences.

“We are pushing the system too far. We must act quickly on climate issues. » In some regions of the Mediterranean Sea in particular, exceptional temperature increases have been observed, up to 5°C above the norm. In some places, notably off Lebanon and Syria, the temperature exceeded 31°C.

While a severe 2022 #marineheatwave is affecting the #Mediterranean Sea, what are the lessons learned from past #MHW?

1⃣ Tens of sessile species belonging to diverse groups (corals, sponges, algae…) can be affected by mass mortality events,…. will new ones enlarge the list? pic.twitter.com/4ghZWnyOag

— Joaquim Garrabou (mostly trying to be at the sea) (@JGarrabou) July 30, 2022

Marine biodiversity is in danger, and so are we

Beyond the rise in temperature, already worrying, there are the many consequences on the marine biodiversity that worry scientists. Of the species could disappear in just a few years, “because, each summer, their optimum temperature is exceeded”, says J. Garrabou. Already about fifty species, found between 0 and 45 meters deep, are affected according to the study, including various corals, algae or sponges. Certain species also contribute mainly to theabsorption of CO₂ issued in theatmosphere.

“The question is not about the survival of nature, because the biodiversity will find a way to survive on the Planet, sadly concluded J.Garrabou. The question is, if we continue in this direction, maybe our society, the humans, will have no place to live. »