The tiny plastic particles also threaten the giants of the oceans. An international team of researchers has examined the risks taken by the large filter-feeding species when they ingest micro plastics together with the water. Whale sharks, manta rays and baleen whales are particularly affected by the absorption of these tiny pieces of plastic.
These particles are omnipresent in our daily environment and have invaded the aquatic world. All marine biodiversity is affected and the filter-feeding species are the most afflicted by this harmful invasion. A recent study, led by the Marine Megafauna Foundation and published in Trends in Ecology and Evolution, proves that the largest fishes in the world are ingesting an alarming amount of micro plastics. These species have the particularity of feeding by swallowing a large quantity of water to extract nutritive particles suspended in the aquatic environment.
Adverse effects not yet identified
Without making a real inquiry, the consequences of micro plastic particles in the body of big filter-feeders are still unclear. “Despite the growing research on micro plastics’ impact in the marine environment, only a few studies are exploring the effects on filter-feeding species. We are still trying to understand the extent of the matter, “says Elitza Germanov, researcher at the Megafauna Foundation Navy.
Scientists responded to the emergency by analyzing tissue samples from live animals and they did found toxic chemicals. The most likely, and almost certain, hypothesis is that the toxic substances contained in these tiny pieces of plastic alter their hormonal system. Their fertility, growth and digestive system are disturbed.
Plus, when they swallow daily thousands of seawater cubic meters, the accumulation of micro plastics disrupt the nutrients absorption necessary for feeding.
Species threatened by a complete extinction
These harmful effects have resulted in the researchers pointing out that the filter-feeding species population is likely to decrease considerably in the coming years. Toxic substances in micro plastics increase their risk of extinction. Elitza Germanov states that “it has become clear that micro plastic contamination may further reduce these species’ population, as many of these animals live long and have few descendants throughout their life.”
Several filter-feeding species are already listed as endangered. In addition to being threatened by overfishing or pollution, they also feed dangerously close to some of the worst pollution hot spots in the world…
Yet these animals are essential for the marine ecosystems and ensure the health of coral reefs. If they were to disappear, the consequences on the marine balance would be catastrophic. Before reaching a point of no return, it is fundamental to reduce drastically the plastic pollution each one of us at its own level.
