How seriously the plastic waste crisis affects marine wildlife is not entirely clear, despite decades of research and gruesome images of plastic-filled whale bellies and a tortoise with a straw closed in its nostrils. A new report from Oceana, a conservation group, illustrates some of what we know about how plastics affect sea turtles and marine mammals in United States waters.
The findings offer a look at a bigger problem.
The authors have focused on sea turtles and marine mammals for practical reasons. These animals are federally protected, so when found in distress or washed dead on the beach, responders must document it. By collecting data from government agencies and marine life organizations across the country, the authors found nearly 1
But the report notes that the number is “grossly underestimated” as humans observe a small proportion of animal deaths in the ocean. However, of the country’s 23 coastal states, he found cases in 21.
“This is the first time we have looked at the problem from a US perspective,” said Kimberly Warner, the report’s author and senior scientist at Oceana. “That brings the problem home.”
In 2016, the United States produced more plastic waste than any other country, and more of that plastic went into the ocean than previously thought, according to a recent study. By 2015, less than a tenth of the world’s cumulative plastic waste had been recycled.
The Oceana report found that in the reported cases, 90 percent of the animals swallowed plastic and the rest became entangled in it. Necropsies often indicate that animals have died from blockages or tears. Other times, ingestion of plastic may simply have weakened the animal or played no role in its death. Overall, 82 percent of the animals died.
The culprits exceed the usual suspects.
In the 1980s, environmental activists warned of the devastating impact of the six-pack rings that trapped marine animals. People started cutting them before they were disposed of, and in 1994 the Environmental Protection Agency ruled that the six-pack rings must be degradable, although the process could take months. Consumers have also been warned to release balloons that could harm marine animals.
Some municipalities, counties and states have recently banned disposable plastic bags, one of the biggest contributors to ingestion and entanglement, according to the report. Plastic wrapping straps have been found, squeezing the necks or bodies of seals and sea lions, naturally curious animals that may have become entangled while trying to play. The howls swallowed many rods.
But the report found many more surprising items caused by the damage. Mesh bags for the production of sea turtles, which also entangle their bodies, have been found along the coast of the Persian Gulf. In 2015, among other items, a wooden-toothed turtle with a toothbrush and a fork was found in Georgia in the digestive tract. Two years later, another turtle with an internal plastic floss was discovered in New York. Food packaging, sandwich bags, mushrooms and even decorative plastic Easter grass were among the items found. A bottle-drenched dolphin in North Carolina had stuck his head in the hole of a flying disk. In Virginia, a DVD case tore this whale’s stomach open.
Many of the victims are endangered or threatened.
More than a dozen endangered species – including sea turtles, Hawaiian monk seals and safe whales – have been swallowed or entangled in plastic. Manatees, those gentle, slow-moving giants that graze seagrass, have made up 700 cases. The report quotes Brandon Bassett, a biologist with the Florida Fish and Wildlife Commission, describing some of what he found in a dead manatee: “Imagine a ball of plastic bags in your stomach, about the size of a melon, and then a bunch of plastic bags that were wrapped and almost like a rope about 3 feet long. “
Scientists are learning more about why animals consume plastic. For sea turtles, a floating plastic bag may look like a jellyfish dish, but that doesn’t explain the bottle caps and hard plastic pieces found in their digestive tracts or feces. One study suggests that plastic begins to smell appetizing when covered with algae and microorganisms.
In South Carolina, a sick carpenter passed nearly 60 pieces of plastic through his digestive system during rehabilitation at a sea turtle center. Minors are more at risk due to their size and underdeveloped gastrointestinal tract. More than 20 percent of sea turtles that swallowed plastic were only months old. Some were only a few days old. A recent Australian study found that just 14 pieces of plastic in their digestive tract significantly increased the risk of sea turtles dying.
Yet plastic waste is not the biggest killer of marine life.
Humans have created all sorts of terrible problems for marine animals: rising sea temperatures, fishing, extracting unforeseen species, a ship hitting them, other marine pollution and habitat degradation.
“Plastics alone may not be as much of a threat as they make us believe,” said Jesse Senko, a research assistant and senior sustainability scientist at Arizona State University. “The scientific community has not done a good enough job to really assess these issues by looking beyond the way it affects the individual animal.”
He believes that images of decaying seabirds with bellies full of plastic make the public and the media focus on plastic, even when other threats are more significant.
After all, plastics and rising sea temperatures are linked; after all, most plastic is derived from fossil fuels.
The Oceana report calls on national, state and local governments to limit the production of disposable plastics and requires companies to offer consumers plastic-free options.
“I’m old enough to remember a time when it didn’t penetrate everything in my life,” Dr. Warner said. “And yet it is built at an alarming rate.”