In the previous post, we covered the various ecological aspects of bioaccumulation, a side effect of water pollution. This article will cover the broad implications of bioaccumulation (i.e. water pollution) and what we can do to clean up the ocean environment.
Generally speaking, there are 3 ways that organisms are ultimately affected by water pollution. First, they experience increased susceptibility to disease because of a suppressed immune system. Second, as previously explained in more detail, there are serious reproductive implications. Thirdly, and most severe, organisms can experience direct mortality due to having ingested or absorbed very high levels of toxins. Ultimately, though, this process (especially that of direct mortality) is very poorly understood, and especially so in cetaceans. This is because of many confounding and conflicting factors, such as multiple chemicals interacting with each other, in addition to a lack of knowledge of how these chemicals act on a physiological level in marine mammals.
There are many cases of mass marine mammal die-offs that are likely attributable to severe bioaccumulation. A few of these cases include mortality of bottlenose dolphins in the Gulf of Mexico (1990,1991,1993), Striped dolphins in the Mediterannean (1990-1992), and Harbor Seals in the North Sea (1988) just to name a few.
How Does Water Pollution Affect Humans
Marine mammals, however, are not always the top-most member of the food chain. In fact, there are many instances when it is we humans who hold that spot. Consequently, bioaccumulation in humans appears to be the most severe of all in some cases. Breast milk of mothers in Greenland was tested and was found to be toxic with mercury. This is most likely due to the cultural habit of hunting and eating whale. Breast milk of females in India and China was also found to be some of the most toxic in the world, and this explanation has less to do with culture and more to do with the level of pollutedness of the environment.
So what can we do to try and improve things?
Very little is known of the trends among bioaccumulation and marine mammal physiology, disease, or population dynamics. The most useful of information would be found in large sample sizes that could be partitioned into significant parameters such as age, sex, location, habitat quality, reproductive status, feeding habits, and nutritional status. Unsurprisingly, information of this nature is most often impossible to obtain among marine mammal populations due to ethical and political obstacles. When possible, though, as much of this information should be sought after and analyzed. This will enable authorities to distribute information and implement regulations that can help facilitate the detoxifying of our environment and of the bodies of its inhabitants, dolphins and humans alike.
How To Stop Water Pollution
At home, a few things we can do to promote a healthy environment include avoiding disposable plastic products, and also choosing organic produce and grass-fed/sustainably raised beef and dairy. In doing so, we make a statement with our dollar in support of sustainable farming that doesn’t flood the environment with harmful chemicals which, as you now know, ends up not only in dolphins, but also in you!