The dead ones washing up on beaches are “just the tip of the iceberg.”

Canadians are celebrating the birth of a baby orca off the coast of British Columbia. The tiny calf was seen swimming with its mother and another female elder on May 31, and was estimated to be just a few days old. Its coloring is still orange and black, which is typical for the first year of life.

There has been an outpouring of support for this little whale. Its birth is the first successful one since 2016, but then that calf died last year. Its grief-stricken mother pushed its body through the water for a week afterward, making headlines around the world.

This birth is a sign of hope, but I can’t help thinking about the tremendous odds this poor calf will have to overcome if it is to survive – namely, the threat of plastic. A recent article by Vox looked specifically at the issue of whales and plastic, following a spate of dead whales washing up on beaches with large quantities of plastic in their bellies. The article asked, “Whales are among the more intelligent creatures in the ocean, so why aren’t they smart enough to avoid eating plastic?”

Part of the problem is that plastic is already in their food. The krill and plankton that baleen whales filter out of the water have often consumed microplastics (another alarming fact), which then move into the whale’s stomach. These pieces are tiny but harmful, leaching toxic endocrine disruptors. Vox cites Lars Bejder of the Marine Mammal Research Program at the University of Hawaii:

“These baleen whales filter hundreds of thousands of cubic meters of water per day. You can imagine all these microplastics they encounter through this filtration process that then become bioaccumulated.”

Toothed whales such as sperm whales, dolphins, and orcas use their teeth to capture and tear prey, then swallow it whole or in large chunks. This makes these animals more susceptible to ingesting large pieces of plastic, both inside their prey and when they mistake floating bottles, bags, and other detritus for food. The result is deadly:

“Once ingested, the plastic piles up in the whale’s stomach. It can then obstruct bowels, preventing whales from digesting food and leading them to starve to death. It can also give a whale a false sense of being full, leading the whale to eat less and get weaker. That leaves it vulnerable to predators and disease.”

There have been a lot of dead plastic-filled whales on beaches recently – one in the Philippines, one in Sardinia, another in Sicily last week – but these are likely only a fraction of the ones that are actually dying from plastic ingestion. Bejder called it “the tip of the iceberg.” For instance, we know that in the Gulf of Mexico only 2 to 6 percent of carcasses wash up on shore; the rest fall to the seabed, and that’s likely the case in the rest of the world’s oceans too.

So while we celebrate this little orca’s arrival in the world, we should be mindful of how our at-home habits affect it survival and that of its fellow whales. It’s more important than ever that we stanch the flow of plastic into the oceans, which is currently estimated to be around 8 million metric tons, or roughly the size of the Great Pyramid of Giza.