Unquestionably, plastic pollution is a global scourge. Thanks to an over-reliance and overuse of single-use plastics, a poor recycling infrastructure, not enough industry or governmental momentum into switching over to something more sustainable and, perhaps, an imprecise understanding of how to handle the problem, the oceans are home to hardy plastics, from the macro to the micro.
It’s unclear at present what effect microplastics are having on marine life – and us, seeing as we often eat marine life – but it’s quite clear to see what happens when wildlife suspects larger pieces are made of food and tries to eat them. A heartbreaking new paper in Scientific Reports attempted to quantify how deadly plastic ingestion like this is for sea turtles, and they found that all it takes sometimes is one single piece.
Making such a calculation is a grim and difficult endeavor. Each sea turtle will be different from the last, with some able to handle more plastic than others. The amount that each sea turtle ingests will also vary wildly depending on the availability of plastic in the area.
In order to get the best estimate they could, two datasets were considered: one featuring necropsies of 246 sea turtles, and another featuring 706 of them included in a national strandings database. This revealed that, on average, a juvenile sea turtle that has eaten 14 pieces of visible plastic has a 50 percent chance of dying as a result.
The study, led by the Commonwealth Scientific and Industrial Research Organization (CSIRO) and the University of the Sunshine Coast, points out early on that sea turtles were among the first organisms observed to be eating plastic. One paper, dating back to 1982, describes how plastic bags were found in the intestinal tracts of leatherback marine turtles.
Indeed, the plastic pollution problems has been known about for at least half a century, but despite this, it’s only got far worse. We know that there’s a lot more plastic in the ocean than ever before, and we know animals eat it, but specific details about how much is being eaten and what effects this has on wildlife has proved harder to pin down.