Ocean Blues? Microplastics and Megafauna

Feeding manta with plastic in water, Indonesia. Photo Source: Elitza Germanov, Marine Megafauna Foundation

The top environmental news this week?  The effect of microplastics on large filter-feeding sea creatures such as manta-rays, whale sharks, and baleen whales.

A recently published study in the journal Trends in Ecology & Evolution (Trends) looked at how filter-feeding megafauna may be impacted by exposure to microplastics and related toxins. The results are not encouraging.

Trends researchers note that it’s difficult to measure the exact quantities of microplastics megafauna intake. The best way to accurately determine the amount ingested is by examining stomach contents. Since many of these creatures are on by the International Union for Conservation of Nature’s (IUCN) list as globally threatened species, scientists will not harvest them.

However, investigators have developed other methods to determine microplastic intake in these creatures. Based upon these other approaches, it is estimated that “whale sharks may be ingesting 171 items on a daily basis” and the BBC reported, “fin whales in the Mediterranean Sea swallow about 2,000 microplastic particles per day.”

The Trends investigators are concerned that swallowing the indigestible plastic particles may “block nutrient absorption and cause damage to the digestive tract of animals” and that long-term exposure may “alter biological processes, leading to altered growth, development, and reproduction, including reduced fertility.”  Long-term exposure is especially disconcerting since these long-lived animals have few offspring throughout their life.

The ultimate goal of the Trends researchers is to raise awareness in communities, governments, and industry so that the impact of microplastic pollution can be lessened. They are hoping to “change behaviors around the production, management, and use of plastics.”

The message may be catching on.

In the U.S. and abroad, there has been a steady increase in concern over plastic consumption and disposal. Many cities and states are banning the use of plastic bags or encouraging consumers to bring their own reusable bags. Forester Research noted a campaign to ban plastic straws in coastal cities both in the U.S. and other countries.

The United Kingdom and the United States have banned the addition of microbeads and microplastics to cosmetics and personal care products. The Guardian reported in early January that the European Union is “waging war against plastic waste” with a goal of having “every piece of packaging on the continent (be) reusable or recyclable by 2030.” A very noble goal indeed.

Still, legal changes can only go so far to help protect our planet as well as ourselves. As long as consumer demand is strong, manufacturers will continue to meet the demand. It’s ultimately up to us to change our behavior and reduce, reuse, and recycle.

What is one thing you can do this week to help reduce our dependence upon plastics?