Marine mammals under threat from micro plastics

5th Feb 2018

Marine pollution is continuing to present a serious threat to marine life, with a new study suggesting that the risk from micro plastics to whales, some sharks and other marine species is increasing.

Some marine mammal species, such as baleen whales and basking sharks, have evolved to swallow thousands of cubic metres of sea water a day, and feed by filtering it for plankton and other small organisms. They are now ingesting the tiny particles of plastic which are now spread across the world’s oceans, which stops their ability to absorb nutrients and may even cause toxic side effects.  The authors of this new study have warned that some species of marine mammals could be at threat of extinction with the damage caused by micro plastics combined with other threats such as bycatch and over fishing. 

The study, which has been published in the journal, Trends in Ecology and Evolution, has advised that more research needs to be done into large marine animals so that the effect of micro plastics can be better understood. We know from necropsies of marine life that larger plastic is causing huge damage, the impact of microplastic is less apparent but just as significant.

One of the co-authors of the study, Elitza Germanov has told the Guardian ‘Despite the growing research on micro plastics in the marine environment, there are only a few studies that examine the effects on large filter feeders. We are still trying to understand the magnitude of the issue. It has become clear, though, that micro plastic contamination has the potential to further reduce the population numbers of these species, many of which are long-lived and have few offspring throughout their lives.”

Maria Cristina Fossi, who is also a co-author of the study added that, though filter feeders don’t seem to be killed by microplastic alone, they could produce “sub-lethal effects” which would still damage their health.

In ORCA’s, The State of European Cetaceans 2017, we looked at the threat of marine pollution and plastics and how this is becoming an increasing problem throughout the world’s oceans. The UK Government has also recently banned the use of microplastic in certain types of cosmetic, but continuing to address this issue is a key step in mitigating the damage of plastics.