How do some of the materials in the clothing we wear endanger marine life and the undersea environment?

Question

I was recently told that many of the clothes we wear are made up of materials that are dangerous to marine wildlife, and the undersea environment. I'm curious as to whether or not it's true.

I know marine animals perish from getting entangled in man-made things like nets, scuba diving gear, traps, remnants of broken boats. Sea animals can choke on man-made objects in the water that look like food but aren't. Fish which have had hooks in their mouths can suffer permanent damage, or death, even if the hooks are no longer there. Other man-made dangers exist, but I haven't heard of this one.

The question is not about the clothing items, meaning the risk of getting tangled up or eating them. It's about materials used to make the clothes.

If this does happen, which materials are they, and how do they cause the damage to wildlife and the undersea environment?

I'm in the United States. I'd be very interested to hear if this is a worldwide problem, but if that's too broad, the answers can include any number of areas as long as The United States is one of them.

Answer 1

Much of our clothing, particularly outdoorsy technical clothing, is made of plastic (nylon is a plastic). The plastic in our clothing is largely inert, but it is subject to mechanical wear and tear. Every time you wash your plastic clothing small bits of bit are broken off, and are distributed throughout the environment. How far they go depends on how your waste water is managed. These small bits of of plastic are called microplastics.

Microplastics are now ubiquitous in the oceans. One concern is that they are being swept up at the bottom of the food chain in plankton and filter-feeders. From the wiki link:

It can take at least 14 days for microplastics to pass through an animal (as compared to a normal digestion periods of 2 days), but enmeshment of the particles in animals' gills can prevent elimination entirely.[50] When microplastic-laden animals are consumed by predators, the microplastics are then incorporated into the bodies of higher trophic-level feeders. For example, scientists have reported plastic accumulation in the stomachs of lantern fish which are small filter feeders and are the main prey for commercial fish like tuna and swordfish.[59] Microplastics also absorb chemical pollutants that can be transferred into the organism's tissues.[60] Small animals are at risk of reduced food intake due to false satiation and resulting starvation or other physical harm from the microplastics.

This is an area of active research and the actual harm to wildlife and particularly to humans is still being debated. Whether end-consumer clothing is a significant source of microplastics compared to fishing gear and industrial sources is also hotly debated. I can tell you that I've stood on a remote beach on Molokai in the Hawaiian islands and seen hundreds of yards of beach covered like a mosaic with tiny bits of plastic.