Pollutants that have been released into the environment over the last several decades have accumulated in our seas and oceans. The entire marine food-chain is contaminated and those living organisms at the top of the food-chain are particularly so: polar bears, large cetaceans, and predatory fish. Several studies carried out at the University of Liège have measured the impact of some organic pollutants on the thyroid glands of sea bass, a fish which is very present along our coasts, but also on our plates. The results are not very reassuring.

In parchment with fine herbs, grilled with fennel or à la provençale, sea bass is a feast for the taste buds. But for several years, scientists have been sounding the alarm bells: as with many other sea fish, the sea bass (known as « wolf » by the people of the Mediterranean) is a victim of pollution, particularly by “endocrine disrupters”. These are chemical products like PCBs, formerly used as an electrical insulator, or DDT, an insecticide used in the fight against malaria. These organic pollutants tend to accumulate in living organisms and as they resemble natural hormones, they disrupt the functioning of some very important glands such as the thyroid, the pituitary, the pancreas, the ovaries and the testicles. The biological functions under threat are vital: reproduction, heat regulation, growth, etc.

The marine environment is particularly sensitive to this pollution because once the offending substances are emitted into the environment they are extremely persistent. It takes several decades before they are broken down and by following the flow of water they make their way to the seas and oceans where they first contaminate small organisms such as phytoplankton, before climbing the food –chain: zooplankton, small fish, large carnivorous fish and large cetaceans. By eating sea bass in parchment or a tuna salad we place ourselves at the top of this food-chain and we ingest the PCBs or the insecticides that we have dumped into the environment many years previously. In other words, the health of fish and, by extension, that of the oceans is also our health. Joseph Schnitzler, a researcher with the Oceanology Laboratory of the University of Liège explains: “We have calculated that by eating a sea fish like sea bass three times a month, we can exceed the PCB threshold considered to be harmful to health. This is particularly true if the fish originates from extremely polluted coasts like the North Sea.” When we see that certain studies have already shown disruption to the reproductive process in an animal like the polar bear which is also at the top of the food chain, we have reason to worry.