Toxic Chemicals Found in Whales and Dolphins, Ever since the 1950s, scientists have been trying to make the world take notice of the existence and impact of ocean pollution. Before that period, it wasn’t even known if oceans could be polluted, because a popular belief at the time was the sheer volume of the oceans would be enough to spread out any pollutants that are dumped into it far enough apart that the concentration of pollutants would be basically negligible. Now we know that that is not true.
Even now, our knowledge of the magnitude of pollution on marine animals is limited, because of the lack of availability of animals to examine and test. To try and fill some of these gaps in our knowledge, researchers performed necropsies (animal autopsies) on 83 beached animals belonging to 11 different species to check the levels of pollutants and pollutant-caused damage to their tissues and organs. According to Annie Page-Karjian, a clinical veterinarian at FAU (Florida Atlantic University), a specialist in marine animals and the lead author of the paper-based on this study that was published in Frontiers in Marine Science, whales and dolphins are the ideal subjects for marine toxicology research because of their eating habits and lifespan (averaging around 15-16 years for dolphins, and some whales even having an average lifespan of 200 years).
Dolphins and whales are usually at the top of their respective food chains (dolphins have even been known to hunt game for sport, similar to another familiar species that is at the top of its food chain), which is a problem in a polluted environment due to a process known as biomagnification. In a nutshell, biomagnification is the exponential increase of the concentration of toxic impurities and pollutants the higher up you go in a food chain.
One of the disastrous cases of this phenomenon was seen in a Gervais’ Beaked Whale, beached in Florida in 2017, which had the highest liver concentration of Arsenic (an element known to have carcinogenic properties) ever reported in a marine animal, despite the distance of their natural habitats from human settlements. Similarly, other animals on examination also threw up high concentrations of other harmful elements like Mercury, and diseases like cancers of organs like the kidneys and testicles.
These results are glaring red flags and calls to action, if not out of empathy for marine animals then out of self-preservation, for humans are in fact directly affected by the pollution of seas and oceans through the same phenomenon mentioned above: biomagnification, with fish making up 20% of over 3.3 billion people’s annual protein consumption.
