An alarming dolphin study

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Taken from Island Connections:

An alarming dolphin study

A scientific study has revealed that several species of dolphins in the Gulf of Cádiz and the Straits of Gibraltar have been accumulating contamination from flame retarding materials and other prohibited substances.

Bottlenose dolphins are at the top of the food chain and are therefore particularly vulnerable to accumulating high loads of toxins

06.05.2015 - This investigation, in which 67 dolphins in the southern Mediterranean were tested, was led by the Superior Scientific Investigation Council (CSIC), the CIRCE group which is dedicated to the conservation, investigation and study of cetaceans, and with the collaboration of the Loro Parque Foundation.  This is the first time that dolphins contaminated by flame retardants on the Spanish coasts have been analysed.

Despite their prohibition in Europe in 2004, the old flame retardants are still present in the environment, together with their alternatives which are equally persistent.  Although their toxic effects still aren`t known, some studies suggest they could be endocrine and genetic disruptors.

Co-author of the study, Renaud de Stephanis said “In almost 20 per cent of the samples analysed, the results were above the established limits.  For example, for seals, they were above the point where endocrine disrupting effects could be observed, especially affecting the thyroid hormone.  This suggests that these contaminants are a serious problem for animals which are at the top of the food chain, as is the case for dolphins and humans.”

Flame retardants are often added to industrial products such as clothing, electronic equipment, furniture or upholstery to make them inflammable.

According to the scientific magazine Environmental Pollution, over time it has been demonstrated that these contaminants remain in the environment for a long time, they`re very importunate, they accumulate and can have noxious effects on organisms and people.

The Institute of Environmental Diagnostics and Water Studies from the Doñana Biological Station also took part in the study and, according to the Loro Parque Foundation`s scientific director, Javier Almunia, the results raised alarms over the effects these contaminants are having on the cetaceans.  Almunia explained that for now, we know that these contaminants can produce metabolic changes in these animals, but another longer-term study is needed to establish whether there are direct consequences for this species.  He added that finding the answer to this will be complicated because the study would require many more dolphins to run aground.

For many years, the Loro Parque Foundation has been studying marine resources in the Straits, where there`s a large variety of cetaceans.  In the study, the scientists showed that three species, the common dolphin, the common pilot whale and the bottlenose dolphin, which are distributed over diverse areas and have different eating habits, accumulate the effects of flame retardants, and that those species at the top of the food chain accrue the highest level of these contaminants. 

The coordinator of the study, CSIC investigator Ethel Eljarrat, explained that this is because they eat and accumulate the contaminants which are already in their prey.  The dolphins studied occupy different positions in the food chain.  The bottlenose dolphin occupies the highest position, and has the highest level of contamination.

This is all very worrying news for dolphins, which could be significantly helped if humans deposited their unwanted household goods in the correct place, specifically at a so-called ‘Punto Limpio`.   These are specific disposal areas for items such as furniture, electrical or electronic goods and batteries, all of which contain contaminating materials.  You can find out about your nearest Punto Limpio from your local council.