Microplastics Pose Threat To Giant Sea Creatures
In a new study published in the journal Trends in Ecology and Evolution, researchers revealed that giant sea creatures are swallowing large amounts of microplastic every day, which can pose a threat to their health, and possibly lead to the further decline of their population.
Microplastic comes from different sources. They could be the disintegrated parts of larger plastic pieces that broke apart in the water. They may also come from common household products that contain plastic microbeads such as toothpaste and exfoliating soaps.
Whales and whale sharks are filter feeders, which means that they consume large quantities of small prey, such as fish eggs, krill, and copepods, by straining them out of the water.
As the sea becomes increasingly polluted with plastic debris, these giant creatures also swallow large amounts of microplastics, which are similar in size and mass to the tiny planktons that they feed on.
Whale sharks that feed in the Sea of Cortez are believed to ingest about 200 pieces of plastic daily. Fin whales in the Mediterranean Sea swallow close to 2,000 microplastic particles daily.
How Plastic Impacts Marine Creatures
Plastics are known to contain toxic substances such as phthalates and heavy metals. Scientists are concerned over the effects of these toxins on sea creatures.
"Exposure to these plastic-associated toxins pose a major threat to the health of these animals since it can alter the hormones, which regulate the body's growth and development, metabolism, and reproductive functions, among other things," said Maria Fossi of the University of Siena in Italy.
Microplastics can also accumulate in the body of these animals, preventing them from absorbing the nutrients that they need. In worst cases, ingestion of plastic materials could be fatal for marine animals.
In 2016, 13 dead sperm whales washed up on a coast in Germany. The cause of their death was acute cardiovascular failure, but a necropsy on the animals revealed that the creatures had plastic and other hazardous items in their stomach, which could have impacted their health.
In France, as much as 800 kilograms or 1,764 pounds of plastic has been found in a whale carcass.
"Microplastic pollution can impact filter-feeding marine megafauna, namely mobulid rays, filter-feeding sharks, and baleen whales. Emerging research on these flagship species highlights potential exposure to microplastic contamination and plastic-associated toxins," Fossi and colleagues wrote in their study.