Hunting for tuna in the warm Mediterranean

Tick ​​Tick Tick Tick Tick Tick. Suddenly, one of the five fishing rods on the blue and white boat started to make a noise. “Thank you, Mother Nature!” Fishing guide Samuel Al-Jerishi, 42, yells as he puts out his cigarette and lunges at the draw rod. His client Arnaud Fasset (32 years old) also jumps. He puts his newly opened beer into an old cooler box and his trembling hands do combat belt around his hips.

Elgrishi and Vasset place the drawbar in the plastic holder that is attached to the belt. And then it becomes clear why it is a file combat belt Hot: Vasset must fight with his catch: pull, roll, retrieve – over and over again. About twenty minutes later, deep in the blue sea, a white spot could be seen getting bigger and bigger. Half an hour later – the Polo Facet’s blue color had darkened some shades from the sweat of the effort – a six-foot-long bluefin tuna appeared on the surface. After the brilliant animal is measured, cut up and photographed extensively, it is released again. “Sorry!” Elgrishi’s other agent, Gues Domeche (66) screams as the fish rushes in, bleeding.

This is the second bluefin tuna fished by Elgrishi, Vasset and Domeche on Friday from the Elgrishi Rousillon Fishing company’s sport fishing boat off the coast of Saint-Cyprien in southern France. It is very hot, but every now and then a broad white cloud brings a little cooling; The outlines of the Pyrenees can be seen on the horizon. “We are really lucky,” says Elgrishi, a man in light blue clothes who speaks very little. On his polarized sunglasses is an icon of a spiny tuna. “Sometimes you look all day and you don’t find one.”

Read also: Climate Shift: Those long, hot French summers from the 1970s can now be found in the Netherlands

Elgrishi originated in the Mediterranean. His father was also a fisherman and both were great-grandfathers. He feels at home on the water, the sun on his brown skin and with one hand on his forehead, staring at the birds flying over his head to discover where the fish are. Fishing for tuna has changed since childhood, becoming more and more difficult. “In the days of my parents and grandparents, you would have known exactly what time of season the tuna and other migratory fish were and in which channels. But the behavior of the animals is becoming more and more difficult to predict. I now spend a lot of time searching and have to change locations often.”

The change in the behavior of bluefin tuna is due to changing weather conditions and the warming of the Mediterranean Sea. The average sea surface temperature that forms the border between Europe and Africa rose by about 1°C between 1993 and 2020, according to figures from the European Union’s Copernicus Earth observation programme. Temperatures have risen further in recent years, with a painful peak this summer. On the French, Italian and Spanish coasts, temperatures have been measured 6.5°C higher than normal for the season in recent weeks. The water was 28 degrees off the coast of Marseille, in Bastia in Corsica up to 30 degrees.

modest size

“Sea water is warming because the seas store more than 90 percent of the heat energy released by greenhouse gas emissions,” says biologist Françoise Gilles, who specializes in ocean ecosystems, via video link. “This is a process that has been going on since manufacturing and is accelerating more and more.” Warming can be observed in all seas and oceans, but the Mediterranean is especially vulnerable due to its modest size and because the sea is almost completely surrounded by land. According to the Nature Conservancy WWF, the temperature of The Mediterranean Sea Up to 20% faster than other seas and oceans.

Global warming is not only affecting the way bluefin tuna live. The Jeriche fisherman also encounters all kinds of fish that until recently were not found in the Mediterranean at all. “When I was little, for example, we didn’t fish for gold mahi — aka mahi mahis,” he says, passing small fish previously caught through some sort of meat grinder on the side of the boat — the pungent smell of fish spreading across the deck. They are supposed to live around Gibraltar and North Africa. About ten years ago they were first seen near Barcelona and now it’s not a summer that I don’t see them here. ” He also regularly catches barracuda and lionfish: fish that were originally only found in large oceans. And there is more: According to the WWF, “tropical” led The Mediterranean now includes 986 non-native species, of which 126 fish can be found in the Mediterranean.

Read also: Warm, acidic, oxygen-free water: life in the ocean is going through hard times

“Having all kinds of tropical species in the Mediterranean shows how bad the ecosystem is,” says Gill. It is currently difficult to determine the exact results due to a lack of data. “But in general you can say that as invasive species consolidate and existing species start to behave differently, the entire food chain has to be rearranged, which can cause imbalances,” says Gill. An important factor here is that the stress caused by high water temperatures on fish and other animals can make them unable to adapt and thus become more vulnerable. “Hence the disappearance of the species is latent.”

Some fish species and other dominant animal species are likely to expand. An important factor here is that when the water is warmer, the metabolism of organisms works faster, which allows them to reproduce faster. It can already be seen that the lionfish, which eats the larvae of countless other sea creatures, is expanding rapidly. The number of jellyfish in the Mediterranean is also on the rise – something beachgoers won’t miss this summer.

dead zones

And warming has even more consequences for marine life. The higher the temperature of the sea water, the less oxygen it can absorb and so-called dead zones can arise in areas with poor oxygen levels. “this Murtat areas devoid of oxygen, which means that almost all fish and crustaceans die there”, says Gill. In the United States, for example, these areas have already ensured that beaches are filled with dead fish. Zones have already been established in all major oceans of the world and the number is increasing And the size of highly hypoxic areas.While 169 dead zones were identified worldwide in 2007, 415 have been identified so far. They are not yet identified in the Mediterranean, but scientists expect them to appear there as well. almost.

Read also: More and more dead zones in the ocean

While warming has the greatest impact on the changing ecosystem of the Mediterranean, the process is also affected by other aspects of climate change and human behaviour. For example, the increase in the acidity of the water and the change of currents in the sea. Due to a multiplicity of factors and a lack of research, it is not yet possible to derive what marine life will look like in the Mediterranean in a few years.

What is clear is that Elgrishi and his colleagues will have to change their working methods over and over again. “But this is also part of a natural process,” says Al-Jerishi. “Hunters have always had to adapt. Nature is always evolving and will never be empty.” The fisherman tries to do his homework by catching plastic from the water during his sailing trips – on a hot Friday, he spins around to get a plastic cap from a jet ski on the plane and picks up the label from a banana before throwing it into the water. He also wants to contribute to the “re-education” of nature by providing his clients with information about fish species, water flows and the consequences of overfishing.

A changing ecosystem sometimes provides experiences that previously could only be gained from the other side of the world. „Tropical fish MAGNIFIX, mahi-mahis, for example, jump over the water,” says Elgrishi with a twinkle in his green eyes. Unlike bluefin tuna, Elgrishi never throws them back in. “They always go home. They are very tasty.”

Leave a Comment