May 21, 2020 — The following was released by NOAA Fisheries:
How do microplastics end up in killer whale feces?
“There are two ways that the whales could ingest microplastics,” says Kim Parsons, Research Geneticist with NOAA Fisheries’ Northwest Fisheries Science Center. “They could incidentally swallow particles in sea water while eating fish, or they could ingest salmon that are themselves contaminated with microplastic particles.”
She suspects that most of the microplastics in orca poop are coming from the whales’ prey. The particles are traveling up the food chain from gut to gut, from herring to salmon to orca.
But why does it matter for orcas if their guts are full of microplastic particles and fibers?
How ingestion of microplastics affects marine mammals is both poorly understood and scientifically controversial. So the answer is, we don’t know yet, but scientists are concerned for the health of organisms at all levels of the marine food chain.
You might own a reusable water bottle advertised as being free of toxic chemical additives like bisphenol A, or BPA. Many chemicals found in microplastics are pollutants, such as polyethylene, polypropylene, phthalates, and BPA and its substitutes. Some of these chemicals are known endocrine disruptors, which means that the chemicals can disrupt an animal’s natural hormones. The chemicals may affect reproduction, growth and development, and ultimately population viability. When microplastics are moving through the whales’ digestive tract, the harmful chemicals could leach into their bodies.