tic and the Mediterranean are declining faster than they can recover. The meta-analysis of European data collected from 1990-2012 showed that several cetacean species have very high mean blubber polychlorinated biphenyl (PCB) concentrations which are likely the cause of population declines and suppression of population recovery. Even though the US Congress banned PCB production in 1979 and the Stockholm Convention on Persistent Organic Pollutants banned it in 2001, because of PCBs’ environmental toxicity and classification as a persistent organic pollutant, and “despite regulations and mitigation measures to reduce PCB pollution, their biomagnification in marine food webs continues to cause severe impacts among cetacean top predators in European seas.” The study found three out of four species: striped dolphins (SDs), bottlenose dolphins (BNDs) and orcas, or killer whales (KWs) – had mean PCB levels that markedly exceeded all known marine mammal PCB toxicity thresholds.
PCBs are not the only poison in the ocean. Roger Payne, founder and president of Ocean Alliance, presented to the International Whaling Commission annual meeting in 2010, reporting results of studies of cells from sperm whales indicate pollution is reaching the farthest corners of the oceans. Sperm whales like CONNY – the magnificent, one-of-a-kind life-size model built in 1976 by the Connecticut Cetacean Society (now Cetacean Society International) on the grounds of The Children’s Museum — are at risk worldwide. Listed as Vulnerable on the International Union for Conservation of Nature and Natural Resources (IUCN) Red List, populations of these deep-diving toothed whales are scant and require further analyses. In addition, efforts to assess the conservation status of sperm whales and the impact of whaling, including social disruption, on current populations are compromised due to the lack of a good model of sperm whale population structure Global population is estimated to be in the 100,000s, significantly less than pre-whaling numbers which may have been as high as 1,100,000. The greatest threat to Sperm whales had been extensive commercial hunting, particularly of large males, but that has virtually ended although small-scale fisheries still exist in Japan and Indonesia. A number of threats still remain, including entanglement in fishing gear (especially gill nets), collisions with ships, ingestion of marine debris, and ocean contaminants. Heavily depleted populations from whaling days have still not recovered.
The IUCN report reflects studies through approximately 2008, omitting a wealth of science about events from then until now. Between January 9 and February 4, 2016, 29 sperm whales stranded and died on North Sea beaches in Netherlands, France, Britain and Germany, the largest mortality event on record. Mass strandings of sperm whales are not uncommon in the region, with records of sightings dating back to the 16th century. Multiple explanations have been offered, such as the whales searching for food in shallow waters (sperm whales can dive as deep as two miles to find food), disorientation, starvation, depletion of prey -giant squid and octopus, warming of the world’s ocean, and noise from underwater bomb explosions and seismic surveys. Little has been said about a possible culprit – noise from offshore wind farms. Because that area has the world’s largest concentration of offshore wind turbines, it is reasonable to infer that the noise created by the turbines can interfere with whales’ sonar, communication and navigation and could be one cause. Investigation is ongoing.
There is overwhelming evidence that our ocean is in peril, and the health and safety of marine animals is in jeopardy like no other time in history. Regardless, good people continue to do great things to protect and preserve our increasingly endangered cetaceans.
Learn more about CONNY, Cetacean Society International and the World Cetacean Alliance by visiting www.csiwhalesalive.org and www.worldcetaceanalliance.org or check out our Facebook pages.
Patricia Sullivan MS Ed. Educa