Thursday, February 2, 2023

Plastic pollution is inescapable, and it contributed to the death of our sperm whale


(Images--above and at bottom--of marine debris from sperm whale belly, courtesy UH Health and Stranding Lab.)

If you’re a fish or a turtle or most any kind of marine life feeding in the Pacific, it’s hard to avoid the plastic.

Almost all of the sea’s creatures end up ingesting some of it, and that includes the massive (56 feet, 50ish tons) sperm whale that washed up at Lydgate Park last week.

The Ocean Cleanup estimates 5 trillion bits of plastic in the ocean. 

And 1.8 trillion bits in the Great Pacific Garbage Patch, that vast gyre that runs roughly between Hawai’i and the Aleutians and California. 

The World Economic Forum estimates the ocean has 75 to 199 million tons of plastic. 

So if a critter opens its mouth to take a bite of food, it’s hard to miss getting some plastic as well.

And they do.

There are microplastics in squid

Plastics in all species of marine turtles

Plastics in tuna, including canned tuna meat

Plastics in many kinds of seabirds

The Maritime Aquarium in Connecticut estimates that by 2050, the way we’re going, there will be more plastic in the ocean than fish.  

So, no surprise when an adult sperm whale washed ashore dead last week, it had a bellyful. Of plastic.

“A major finding was the number of manufactured items in the whale’s stomach,” said Dr. Kristi West, director of the University of Hawaiʻi at Mānoa Health and Stranding Lab. It could have been enough plastic to cause a blockage, and could have contributed to the whale’s death, West said.

In addition to squid beaks and fish skeletons and other natural food remains, they found chunks of plastic netting, plastic bags, bits of rope, monofilament fishing line, a fishing net float, and several of the odd cone-shaped black plastic devices that are the doors to hagfish traps.

This is shocking, but it isn’t news. Whales of many species, including sperm whales, have been stranding all around the world with plastic in their guts. And the filter-feeding Humpback whales that seasonally slap and leap around Hawai'i are not exempt, although they tend to ingest tinier bits of plastic. 

The study into the cause of the Lydgate  whale’s death will continue with laboratory analysis of organ and other body parts, and it may be a long time before a firm cause of its demise is established, if it is.

And as for the plastics, where does it all come from? Certainly a lot from fishing operations—some of the ropes, and monofilament, and nets, and hagfish traps and plastic floats. But it’s estimated far more comes from the land—blowing off the shore, sluicing down storm drains and, the biggest source, washing down big rivers.

© Jan TenBruggencate 2023


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