Floating microscopic litter in ocean gyres has become a food source for small fish. When larger fish eat the smaller ones, plastic contaminants move up the food chain as well.
Research into the effects of ocean gyre plastic is ongoing, but there is a new––and disturbing–– avenue of research being explored. Small fish, like the abundant lanternfish, are using the detritus as a food source.
According to a study published in the Marine Pollution Bulletin, about 35% of the fish collected on a recent research expedition had plastic in their stomachs. And even more alarming, while researchers expected to find that fish had consumed a few pieces of the denuded plastic––possibly one or two–– what they actually found was much worse. Researchers found that many of the hundreds of lanternfish that were collected and dissected for the study contained around 80 individual pieces of ocean plastic in their bellies.
Lanternfish are deep-sea plankton-eaters who come to the ocean surface at dark to feed. They are the most common fish in our oceans and the major food source for larger game fish like mahi mahi and tuna, which are in turn caught and consumed by humans.
For the study, researchers from the Long Beach-based Algalita Marine Research Foundation, together with the Southern California Coastal Water Research Project, trawled for lanternfish in an area known as the Eastern Garbage Patch, some 1,000 miles off the Southern California coastline. Research into the effects of the floating debris on smaller fish has never before been documented.
Although larger plastic items, such as plastic bottles and containers, are eventually broken down into small fragments by tumbling waves and bleaching sun, it is unclear weather they will ever fully degrade. Ironically, the smaller the fragments get, the more appealing they are as a food source to fish. The minute particles mimic the size, shape and texture of plankton that the lanternfish feed on, endangering the entire food chain, and posing health risks to humans.
The danger of discarded plastic to ocean life such as turtles, fish and marine mammals is well documented. I can’t help but wonder, as we observe World Oceans Day today, now that a more direct danger of contamination to humans has come to light, will we be more aggressive in finding a solution to our ocean plastic problem?