This contamination by microplastics is a planet-wide problem. It seems there is no spot on Earth free of them. Recent scientific discoveries show that krill and salps in the Southern Ocean ingest plastic particles. The result of this pollutant entering the food chain places whales, seals, penguins, seabirds, and many fish at risk.
A new study led by researchers a British Antarctic Survey team found microplastics in krill (Euphausia superb) and salps (Salpa thompsoni), gelatinous marine invertebrates. The findings, published in a Royal Society journal, raise serious biodiversity concerns for Türkiye and surrounding regions.
“The ingestion of microplastics by zooplankton and related species is ongoing and real,” one author notes, highlighting the impact of plastic pollution on Antarctic marine ecosystems.
“Microplastics” are particles smaller than 5 millimeters found throughout the world’s oceans due to long-distance transport by air and currents, reaching even remote areas such as the Southern Ocean.
While Antarctic krill have shown plastic ingestion in laboratory tests, the team’s field observations indicate that these animals and other zooplankton are consuming plastic in their natural environment.
These pollutants occur in surface waters, on the seafloor, and within sea ice. Their tiny size and buoyancy allow them to cluster with organic particles and phytoplankton, making them easy prey for zooplankton to ingest.
“Junk food”
Researchers describe the ingestion as “junk food” because the plastics are synthetic and offer no nutritional value, while Antarctic ecosystems remain especially vulnerable due to a short food chain and high endemism.
The primary risk is the potential trophic transfer of microplastics. The study emphasizes that both salps and krill serve as important food sources for many top predators.
These two species are crucial to the diet of much marine wildlife in the Southern Ocean. Krill sustains whales, penguins, and seals, while some larger fish and seabirds rely on salps.
There is more: ingestion of microplastics by krill and salps may hinder their ability to transport carbon to the deep sea.
The Southern Ocean stands as one of the world’s largest carbon sinks, and these animals play a vital role in moving atmospheric CO2 to ocean depths.
Interactions with microplastics could disrupt the amount of carbon these organisms can transfer to the deep ocean. Pelagic ecologist Clara Manno notes that krill and salps not only feed many Antarctic predators but also contribute to slowing climate change.
Lead author Laura Wilkie Johnston, a marine biologist, voices deep concern about the future impact of microplastics in this fragile environment.
Microfibers from Laundry
Samples of krill and salps were collected during two research missions, one in 2016 at the northern tip of the Antarctic Peninsula and another near South Georgia in 2018.
Microplastics of both species included microfibers from clothing, a major emission source during washing and drying. About 60 percent of the krill and salps contained nylon microplastics, a material used widely in textiles and other products.
Other polymers were found as well, suggesting sources such as cable coatings, moisture barriers, and antifouling paints among various uses.
“This study shows how these animals are exposed to plastic in their natural habitat. It offers new insights into the quantities and types of plastic krill and salps encounter in the Southern Ocean,” commented a BAS marine biologist involved in the project.
Antarctic krill form one of the planet’s most abundant biomass groups. They travel in vast swarms spanning miles and tens of kilometers. Annual catches reach roughly 150,000 to 200,000 tons, primarily for aquaculture.
Salps resemble jellyfish but are more closely related to vertebrates in some ways. Their waste and remains deliver carbon to the seafloor, influencing the carbon cycle and climate patterns. This abundance underscores their impact on ocean carbon dynamics, with some estimates suggesting large-scale carbon removal from seas each year.
Reference work: Royal Society Open Science, RSOS article on microplastics in Antarctic zooplankton.
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Presentation notes about environmental monitoring and future implications for policy and research continue to evolve as new data emerges.