More male fish ‘feminized’ by pollution on Basque coast
Evidence of ‘feminization’ of male fish in the estuaries of Gernika, Arriluze, Santurtzi, Plentzia, Ondarroa, Deba and Pasaia has been discovered. The first cases — 2007-2008 — were detected in Urdaibai, and the most recent data confirm that they are also taking place in other estuaries. Pollutants acting as estrogens are responsible for this phenomenon which, among other changes, is causing ovocytes to appear in male fish.
Members of the Cell Biology in Environmental Toxicology group have discovered evidence of “feminization” of male fish in the estuaries of Gernika, Arriluze, Santurtzi, Plentzia, Ondarroa, Deba and Pasaia. The first cases (2007-2008) were detected in Urdaibai, and the most recent data confirm that they are also taking place in other estuaries. Pollutants acting as estrogens are responsible for this phenomenon which, among other changes, is causing ovocytes — immature ova — to appear in male fish.The UPV/EHU’s Cell Biology in Environmental Toxicology group has conducted research using thick-lipped grey mullet and has analysed specimens in six zones: Arriluze and Gernika in 2007 and 2008, and since then, Santurtzi, Plentzia, Ondarroa, Deba and Pasaia. The acquisition of feminine features by male fish has been detected, to a greater or lesser extent, in all the estuaries, not only in the characteristics of the gonads of the specimens analysed but also in various molecular markers. According to Miren P. Cajaraville, director of the research group, the results show that “endocrine disruption is a phenomenon that has spread all over our estuaries, which means that, as has been detected in other countries, we have a problem with pollutants.”Some of the emerging pollutants detected are in fact responsible for the “feminization” of male fish on the Basque coast and belong to the group of endocrine disrupting chemicals. Chemically, they are very different from each other, but they all have similar effects: due to their interaction with hormones, they destroy the hormone balance and can lead to the feminization or masculinization of the organism. As they are pollutants that have appeared recently, little is known as yet about their effects on the environment and on ecosystems. According to Cajaraville, “our discoveries are significant, because they enable us to know how far these pollutants have spread in our estuaries and rivers and what effects they have; that way, we will be able to adopt methods to prevent them reaching our waters, like legal regulations governing their use.”Despite the fact that they are new pollutants in terms of their effects, the “sources” of endocrine disrupting chemicals can be found in everyday products: plasticisers, pesticides, contraceptive pills, fragrances and detergents, among other things.Some reach the waters after managing to get through the cleaning systems in wastewater treatment plants, and others as a result of industrial or farming activities. So, as far as the Urdaibai Biosphere Reserve is concerned, for example, “our main hypothesis,” says Cajaraville, “is that they come from the water treatment plant. …
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