New NS study finds microplastics in edible parts of lobster tails

A new study from Dalhousie University has found microplastics in the meat of lobsters caught off the coast of Nova Scotia.

Researchers from Dalhousie’s School for Resource and Environmental Studies collected 16 lobsters from four different regions of the province in 2022.

They then tested edible parts of the tail using a special dye that makes the microplastic glow when placed under a microscope.

Various forms of microplastics were found in each of the 16 lobsters analyzed, with an average of six to seven microplastic particles per gram of meat.

Amber LeBlanc is the lead author The study, which was published in the journal Regional Studies in Marine Science Last week.

“I wasn’t very surprised to learn that microplastics were present there,” said LeBlanc, who was a master’s student at Dal at the time of the study.

“However, I think their size was pretty surprising… like, they’re so small. And then the fact that they appear to potentially come from so many different sources.”

The average size of the plastic was 3.65 micrometres – about 30 times smaller than the diameter of a human hair.

The researchers were able to analyze the particles to determine what types of plastics were present, and found that most were polyethylene vinyl acetate, which is commonly found in packaging, laundry detergent pods, coatings and sealants, as well as parts of vehicles and boats; Potentially polyester from clothing fibers; and polysulfone, an industrial-grade plastic that has many applications, including resins painted on ships to prevent organisms from attaching to them.

Lobsters were obtained from four locations, including Lobster Fishing Area (LFA) 34 in the lower Bay of Fundy, LFA 33 on the south coast, LFA 30-32 on the east coast and part of Cape Breton, and LFA 26A along the Northumberland coast between Nova Scotia and Prince Edward Island.

While microplastics were found in all samples, LFA 34 had the highest concentrations in lobsters collected from southwestern Nova Scotia.

However, LeBlanc cautions that given the small sample size of 16 lobsters, more research is needed to know if geographic differences are a trend.

Tony Walker, one of the paper’s co-authors and a professor at Dell’s School for Resource and Environmental Studies, described the concentrations of microplastics in lobster meat as “relatively low” compared to those found in other types of food.

Health implications unknown

Carl Jobst is an associate professor in the Department of Chemistry at Memorial University, and studies the impact of microplastics on human health – particularly early in life.

His research group has found that microplastics are present in blood and placental tissues, but he says there is still uncertainty about whether exposure is high enough to cause adverse effects.

Jobst and his team have also conducted mouse model experiments using high concentrations of microplastics and found that they can cause adverse effects during pregnancy in mice, including impaired fetal growth, altered metabolism, and abnormal brain development.

Jobst said he also was not surprised to find microplastics in lobster meat.

“Microplastics are widespread,” he said. “There are a growing number of studies in the literature reporting on the occurrence of microplastics in humans and wildlife on the highest mountains in the ocean.”

The results of the lobster study are important, Jobst said, but it is too early to draw conclusions about effects on human health.

“I’m not sure I would be willing to conclude that lobster consumption would be a significant source of risk,” he said.

The seafood industry responds

Representatives of Nova Scotia’s seafood industry raised questions about the lobster study, noting that the sample size was small and that microplastics have been found in many different foods, including both sea-based and land-based proteins.

Stewart Lamont, managing director of Tangier Lobster Co., which exports lobster to customers in 13 countries, said he would like to see a comparative analysis of microplastic concentrations in different foods.

“Microplastics are common throughout the food chain. So I’m confident that this is not specifically a lobster issue. I suspect this is a food issue, a social issue that we need to address on a national basis.”

Lamont said he’s not too concerned that the study might impact lobster consumption, since it’s typically a “celebration food” eaten a few times a year, rather than gracing the plate several times a week.

Chris Vascoto is the executive director of the Nova Scotia Seafood Alliance, which represents lobster buyers, exporters and processors.

He said lobster should be viewed in that larger context, given the ubiquity of microplastics in food.

“I think it’s very important for consumers to realize that this is still an excellent protein,” he said. “This is achieved sustainably…and there are many health benefits to continuing to consume fish and seafood.”

Walker, one of the study’s authors, said the purpose of the research was primarily to confirm whether microplastics were present in edible lobster meat and what types of plastics.

He said previous research had only focused on microplastics in the digestive tracts of lobsters.

Walker and LeBlanc say more research is needed to understand the effects of microplastics on crustaceans and humans.