Gulf's plastic trash killing large numbers of endangered species, study finds

The vast majority of marine animals found to have been strangled, internally lacerated or otherwise harmed by the Gulf of Mexico's growing load of plastic waste were threatened or endangered species, according to a new study.

In a first-of-its-kind compilation of wildlife deaths from plastic ingestion and entanglements, marine conservation group Oceana found that 88% of the confirmed plastic-related deaths or injuries in U.S. waters were creatures teetering on the brink of extinction.

In the Gulf, plastic bags, fishing lines, balloons and other waste took an especially heavy toll on manatees and four species of sea turtles, all of which are listed as threatened or endangered under the Endangered Species Act.

"These animals already face a host of environmental problems in the Gulf of Mexico," Oceana scientist Kim Warner said, noting impacts from the oil, shipping and fishing industries. "It's unfortunate they're also at risk from products a lot of us only use for a few moments before discarding."

Of the 263 turtles reportedly killed by plastic in the Gulf, more than half were green sea turtles. Often weighing more than 300 pounds, greens are one of the largest hard-shelled sea turtles. In Florida, a green turtle was found with a plastic ring around its body, causing severe deformity, and a green turtle hatchling was determined to have died from having its intestines perforated by several plastic fragments it mistook for food. On a Texas beach, a dead green turtle was found with a disposable cup stuck to a flipper, preventing it from swimming properly.

The Kemp's ridley sea turtle, one of the most endangered turtle species in the world, appears to be having a particularly tough time with cast-off plastic bags. Several Kemp's ridleys were found dead with bags tangled on their flippers and fragments of bags in their stomachs, possibly indicating attempts to bite away the plastic. One Kemp's ridley is believed to have drowned from the weight of a sand-filled bag wrapped around its neck.

Manatees, which range along the Gulf Coast from Florida to Louisiana, have been found consuming a variety of plastic items, which they appear to eat by accident while grazing on water grasses.

Oceana's review of manatee data indicates that at last 700 had suffered from plastic entanglement or ingestion between 2009 and 2018. Of those cases, most had swallowed plastic fishing line. Manatees are also eating large quantities of plastic balloons and ribbons, which can resemble grasses or be caught in them.

In one case, a manatee died from eating a large amount of plastic shopping bags.

"Imagine a ball of plastic bags in the stomach, about the size of a cantaloupe, and then a bunch of plastic bags that were wrapped and almost like a rope that was about three feet long," said Brandon Basset, a biologist with the Florida Fish and Wildlife Conservation Commission. "On the other end of that was another ball of even more plastic bags that was maybe about half the size of a cantaloupe, and that was in the intestine. That whole mass ended up killing the animal. Stuff like that can lead to not only death, but significant and unnecessary suffering."

Oceana's study relied on records of almost 1,800 animals from 40 different species that had swallowed plastic or become entangled in it.

The available records vastly underestimate the number of actual deaths from plastic waste, Warner said.

"We absolutely don't have the full tally," she said. "These are just the animals that turn up and are seen by somebody, usually on the shore, and are then reported and examined by a trained person."

That means the data skews heavily toward large animals that spend time on or near the coast. "Sea birds, invertebrates, fish — all of those are not usually included in the reporting," Warner said.

But it's clear that almost all marine species are affected by plastic waste. Plastic particles have been found in Gulf menhaden, small schooling fish that serve as food for many larger species, as well as bottom-dwelling worms and other deep-sea critters.

Scientists estimate 15 million tons of plastic ends up in the world's waterways each year. That equates to about two garbage trucks dumping full loads of plastic trash in the ocean every minute.

The problem is likely to worsen. Plastic production is expected to quadruple over the next 30 years and the amount of plastic entering the ocean could more than triple during the same period, according to a recent study published in the journal Science.

The Gulf is already loaded with one of the highest concentrations of plastic waste. In 2017, LSU scientists found that the richness of plastic particles and larger trash items in the waters off Louisiana are on par with the Black Sea and the mouth of China's heavily polluted Yangtze River.

The Mississippi River could be to blame for much of the Gulf's plastic problem. The river acts as a giant collector of waste that eventually flushes into the Gulf.

The issue made headlines last summer when a cargo ship moored in New Orleans spilled several tons of plastic particles, known as "nurdles," into the Mississippi.

Several government agencies spent weeks determining which of them should respond to the spill before eventually deferring to the ship's operator, CMA CGM Group, to mount a voluntary cleanup. By then, most of the nurdles were widely dispersed on riverbanks or had already flowed into the Gulf.

Warner said the New Orleans nurdle spill and others like it underscore national, state and local government indifference toward plastic waste and the difficulty of cleaning it up once it's in the water.

Better to quit producing so much of the stuff — especially the disposable kind, the Oceana report says. The group's scientists offered a series of recommendations to curb marine plastics. Chief among them were broad-scope government policies that reduce or prohibit single-use plastic items like take-out food containers, straws, water bottles and grocery bags. Governments and companies should also move to establish widespread use of reusable and refillable containers and packaging, the report recommends.

"We have an opportunity to rethink our disposable lifestyle," Warner said. "It's not rocket science. We used to do this before we became a disposable culture and used plastic for everything. And we can do it again."