How does science explain this phenomenon? We interviewed Julien Dubreuil, a marine biologist

For several months, octopuses ravaged the bottom of the Atlantic coast. Lobsters, muffins, scallops, no species are immune to the voracious appetite of cephalopods. A big loss in the profits of fishermen in western France because octopuses sometimes get into traps and gobble up the catch. Unexpected new competition disrupts the marine ecosystem and the fishing economy.

To understand where this phenomenon comes from and what solutions there may be, we interviewed Julien Dubreuil, a marine biologist in Quimper and project director of the Regional Commission for Marine Fisheries and Maritime Education of Brittany (CRPMEM).

Julien Dubrell, have you noticed the octopus breeding?

We are clearly in a quite exceptional year compared to the last historical series. The phenomenon of octopus proliferation has already been documented, and we have some in the scientific literature for the years 1950-1960. I consolidate the last numbers of Morbihan. Important numbers like this, We haven’t seen one in the last ten years of data. We’re 20 times bigger than we had last year, and therefore on really amazing payloads.

What are the reasons for this spread?

What makes such a spread likely to occur is the favorable hydro-climatic conditions that have allowed the species to have good reproductive success in the past year. The bred species experienced more juveniles reaching adulthood and because they are a very fast-growing species, they do not live very long. In general, octopuses live between one and two years, they must grow very quickly and therefore eat a lot. She has a digestive system that is adapted to eating a large amount of food, especially oysters, crustaceans, crayfish, crabs, scallops, glass and oysters. It is the target staple food.

How do we protect these resources and fishing companies?

It’s very complicated. There are several axes to work on. Already, we are forced to adapt management. We talked about the first shell deposits in Morbihan, which opened this week [mi-octobre 2021, NDLR]Management has been fully adapted, fewer licenses granted, fewer hunting days in the annual calendar and less hunting time. It is a very necessary adaptation to the fact that there are fewer shells in the deposit.

Another necessity and it is a paramount necessity, which is the ability to hunt and bring back all these predators. The octopus must be brought back, whether by shovel, trap, or trawl. It has commercial value and above all, what must be understood is that the octopus on the ground is an octopus that no longer eats shellfish on the beds. That’s why I’ve been talking to you about supporting the public authorities, they need to be alerted and we have to be flexible about regulations.