There has been an unprecedented number of dolphins washed up on Cornish shores of late. 25 dolphins were recorded by Cornwall Wildlife Trust in the first two weeks of January. That’s six times the number recorded in the previous year.
Furthermore, this increase isn’t an isolate case. During the first three months of 2016, the Cornwall Wildlife Trust found 61 whales, dolphins and porpoises dead around the local coastline—the highest on record since 2006.
While it is sometimes difficult to identify one single cause of death, there are many human factors which threatens marine life. A key factor is toxic waste.
In a recent study (conducted by Dr Paul Jepson, from the Zoological Society of London) of more than 1,000 whales, dolphins and porpoises across Europe, it was discovered their blubber contained some of the planet’s highest concentrations of Polychlorinated biphenyl (PCB).
PCB is a man-made chemical used for a variety of applications including: insulating fluids for transformers, plasticizers in paints and cements and hydraulic fluids.
In 1979, the US banned PCB production and a United Nations treaty was drawn up in 2001 to eradicate the pollutant. Numerous studies found PCB to cause cancer in animals and to be a human carcinogen.
Of the study, Jepson said:
Our findings show that, despite the ban and initial decline in environmental contamination, PCBs still persist at dangerously high levels in European cetaceans. Few coastal orca populations remain in western European waters. Those that do persist are very small and suffering low or zero rates of reproduction.
The risk of extinction therefore appears high for these discrete and highly contaminated populations. Without further measures, these chemicals will continue to suppress populations of orcas and other dolphin species for many decades to come.
Of the increased deaths, marine conservation manager at the Cornwall Wildlife Trust, Ruth Williams said:
There has been a high number of dolphin sightings recently. Fish do move around, so the fact that they are close to shore isn’t completely unusual. It could mean we are seeing the deaths more prominently. When they die further out, only around 10 % will wash up on beaches.
Pollution is a major issue, particularly the effects of PCBs, which is a fairly nasty chemical that has got long life in the marine ecosystem and it’s not toxic so much to the animals themselves, but it reduces their immunity making them more susceptible to other disease.
We examine every animal that washes up on the beaches and assess each one individually and look into it in as much detail as we can. We ask anyone who sees anything to report it in so we can get that evidence.
As Williams points out, for anyone who spots an injured or deceased marine animal, contact the local authorities. This can help them identify the problem and keep track of affected areas.
Unfortunately, as PCB proves, we’ve been so destructive in the past that even when we change our behaviour the consequences of our actions are still felt years later. This proves we need to urgently act, change our unsustainable ways and ensure we protect our ecosystems.
Small changes such as reducing plastic waste, recycling, switching to greener energy sources, can really help to make the difference. It’s never to late to change.
Featured image: Minke Whale found on Morro Bay Sandspit. Photo: Mike Baird