The Plight of Seabirds
By Stephanie Macdonald
Over the years as the amount of plastic pollution in our oceans has increased it became inevitable that our throw away society would have detrimental effects on marine life. Plastics, often used just once, are designed to be durable and can potentially remain in the ocean for years. Caught up in currents and floating in gyres it can be decades before they eventually break down or sink to the ocean floor.
PLASTIC OR PLANKTON?
As plastic breaks down into increasingly smaller fragments they are easy for animals to consume and confuse for edible organisms. In many cases microplastics look indistinguishable from plankton causing trouble up the food chain. Estimates suggest by 2050 there will be more plastic than fish by weight in the ocean and The UN has estimated that as many as 51 trillion particles of microplastic are in the world's ocean. Marine organisms mistake plastics for plankton, fish eggs and fish, causing it to enter the food chain. These organisms that have consumed plastics are then eaten by larger sea creatures. There is no doubt this is having disastrous effects, plastics do not discriminate and all forms of organisms are falling to their peril.
Some of the biggest victims of plastic pollution are seabirds. Wilcox et al. investigated the ingestion of plastics in 186 species of seabird, their research estimates that currently a staggering 90% of the world’s seabirds have fragments of plastic in their stomachs compared to only 5% in 1960. What is more frightening is the fact their models estimate that by 2050 all but 1% of seabirds will have ingested plastic. As birds fly around fishing and foraging for food they feed off the colorful attractive bits of plastic they believe to look and smell like prey. Not only do adult birds eat this plastic, chicks in their nests are fed plastic material leading to malnutrition and starvation, as debris is ingested instead of nutrient rich food. From birth the birds do not stand a chance, in many cases the weight of the plastics in their stomachs means they are too heavy to take flight and do not have the energy to fight strong offshore winds.
Home to many species of seabird, Midway Atoll is one of the most remote places in the world, located in the Pacific Ocean it is positioned on the edge of the North Pacific Gyre. Here plastic from the Pacific coastlines of Asia and America swirls in global ocean currents and collects in a large area. This small island is home to Albatross which are dying in huge numbers due to the plastic epidemic circulating around their home. When these birds swoop into the sea to hunt the are more likely to be scooping up a bottle cap or a lighter due to their attractive resemblance to food.
A study conducted on Northern Fulmars found on average birds had 0.385 grams of plastic remnants in their stomachs, which works out as 17% of the birds total body weight. The birds that underwent necropsies for this study were found beached on the coast of the US and Canada in which many are believed to have died in relation to plastic consumption. The consequences of eating plastic for many organisms means they perpetually feel full as they cannot digest the plastic that remains in their stomachs causing them to starve to death. Additionally these innocent organisms have an exceptionally high risk of plastic getting stuck in their gullet and the risk of suffocation, intestinal blockage, malnutrition, intestinal blockage, or slow poisoning from chemicals in or attached to the plastic.
Teams of scientists across the word are fighting to protect sea birds, none more so than Dr. Jennifer Lavers and Dr Ian Hutton who are two scientists working tirelessly to flush plastics out of the stomachs of shearwater birds in a process called ‘lavage’ a tube is guided down the throats of bird’s in order to flush out its stomach contents. Not only does this technique provide data into the plastic ingestion it also enables the plastic to be removed from their stomachs giving the fledglings a fighting chance.
Yet again, the plight of seabirds is an extended reminder that an active effort is necessary to reduce daily plastic consumption.