Shannon dolphins suffer lowest toxicity in Europe

Bottlenose dolphins in the Shannon Estuary are the least contaminated in Europe, but levels are still above the toxic threshold thought to impact on their health and reproduction.

A study explored levels and trends in organochlorine residues in populations throughout Europe, including bottlenose dolphins and killer whales in Ireland. Biopsy samples from eight dolphins resident in the Shannon Estuary were included in the study, which is the largest review of persistent pollutants in dolphins in the world.

The results showed that although many of the most toxic organochlorines are no longer produced, concentrations in a range of species and populations throughout Europe are so high to impair reproduction and could lead to extinction.