A new study from Dalhousie University has found microplastics in lobster meat caught off the coast of Nova Scotia.
In 2022, researchers from Dalhousie's School of Resources and Environmental Studies collected 16 lobsters from four different areas of the province.
They then tested the edible parts of the tails using a special dye that makes the microplastics glow under a microscope.
Each of the 16 lobsters analyzed were found to contain different forms of microplastics, with an average of six to seven microplastic particles per gram of meat.
Amber LeBlanc – Lead Writer study published in the journal Regional Studies in Marine Science last week.
“I wasn’t too surprised to find out that there were microplastics present,” said LeBlanc, who was a master’s student at Dal at the time the study was conducted.
“I think the size of them was really surprising, though… Like, they're so, so small. And then the fact that they seem to potentially come from so many different sources.”
The average size of the plastic was 3.65 micrometers – about 30 times smaller than the diameter of a human hair.
The researchers were able to analyze the particles to determine what types of plastic were present and found that most were polyethylene vinyl acetate, which is commonly found in packaging, laundry detergent pods, coatings and sealants, and parts for vehicles and boats; polyester, possibly from clothing fibers; and polysulfone, an industrial-grade plastic that has many uses, including resins applied to ships to prevent organisms from attaching to them.
The lobsters were sourced from four sites that cover Lobster Fishery Area (LFA) 34 in the lower Bay of Fundy, LFA 33 on the south shore, LFA 30-32 on the east shore and parts of Cape Breton, and LFA 26A along the Northumberland coast between Nova Scotia and Prince Edward Island.
Although microplastics were detected in all samples, the highest concentrations were found in lobsters collected in southwestern Nova Scotia in LFA 34.
However, LeBlanc cautions that given the small sample size of 16 lobsters, more research is needed to see if the geographic differences are a trend.
Tony Walker, one of the paper's co-authors and a professor in Dal's School of Resources and Environmental Studies, described the concentration of microplastics in lobster meat as “relatively low” compared to concentrations found in other types of food.
Health effects unknown
Karl Jobst is an assistant professor in the Department of Chemistry at Memorial University and studies the effects of microplastics on human health, especially in early life.
His research team has found that microplastics are present in blood and placental tissue, but he says there is still no certainty that exposure is high enough to cause side effects.
Jobst and his team also conducted experiments in mouse models using elevated concentrations of microplastics and found that they can cause side effects during pregnancy in mice, including fetal growth restriction, altered metabolism, and abnormal brain development.
Jobst said he, too, was not surprised by the discovery of microplastics in lobster meat.
“Microplastics are widespread,” he said. “There are more and more studies in the literature reporting the occurrence of microplastics in humans and wildlife on the highest mountains, in the ocean.”
The lobster study's results are important, Jobst said, but it is too early to draw conclusions about the impact on human health.
“I'm not sure I'm ready to conclude that eating lobster will be a significant source of contamination,” he said.
The seafood industry is responding
Nova Scotia's seafood industry raised questions about the lobster study, noting that the sample size was small and that microplastics were found in many different foods, including proteins from both ocean and land sources.
Stuart Lamont, managing director of the Tangier Lobster Company, which exports lobster to customers in 13 countries, said he would like to see a comparative analysis of the concentration of microplastics in different food products.
“Microplastics are found throughout the food chain. So I'm pretty confident that it's not just a lobster problem. I suspect it's a food problem, a social problem that we need to address at a national level.”
Lamont said he's not overly concerned that the study might affect lobster consumption since it's typically a “holiday food” eaten several times a year, not something that graces the plate several times a week.
Chris Vascotto is executive director of the Nova Scotia Seafood Alliance, which represents lobster buyers, exporters and processors.
He said that given the ubiquity of microplastics in food, lobster should be viewed in that broader context.
“I think it’s really important for consumers to realize that this is still a great protein,” he said. “It is sustainably sourced… and continued consumption of fish and seafood provides many health benefits.”
Walker, one of the study's authors, said the study was aimed primarily at confirming whether microplastics are present in edible lobster meat and what types of plastic are present.
He said previous studies only looked at microplastics in the digestive tract of lobsters.
Walker and LeBlanc say more research is needed to understand the impact of microplastics on crustaceans and on humans.
