Industrial fishing ships dumped about 80,000 metric tons of fish back into the ocean in the waters of Saint Pierre and Miquelon, a French territory near Canada, over seven decades. This happened between 1950 and 2022, according to a new study in the science journal Cybium.
Researchers compared the wasted fish to filling 32 Olympic swimming pools. Almost all of this dumping happened unreported and unmonitored, according to the analysis.
The study, led by researchers from the Sea Around Us initiative at the University of British Columbia, found that fishing vessels in the French archipelago caught about 1.2 times more fish than official records indicate. Most of the unreported catch consisted of industrial discards, while a significant portion also came from seafood caught on bait lines in artisanal cod and groundfish fisheries during the 1950s and 1960s.
According to a report by website Phys.org, lead author Anna Luna Rossi stated the massive scale of fish dumping was highly unexpected given the region’s history of North Atlantic cod stock depletion and the 1992 Canadian cod fishing ban. Rossi uncovered these findings for her master’s thesis with the Sea Around Us initiative at the University of British Columbia’s Institute for the Oceans and Fisheries.
The introduction of industrial trawlers in 1952 caused a steady decline in traditional dory fishing in Saint Pierre and Miquelon, which concluded with the complete collapse of both local and industrial sectors in 1992. The study highlighted that this collapse followed nearly two centuries of artisanal fishing, with researcher Rossi noting the unexpected discovery of massive fish dumping in the already damaged region.
Industrial catches increased from the 1950s through the 1970s and peaked in the 1980s, aided by French government subsidies for fuel and fishing equipment. Researchers say these subsidies intensified pressure on already overexploited Atlantic cod stocks.
After fishing quotas were introduced in 1994, industrial catches stabilised, while artisanal fishers largely shifted away from cod to species such as snow crab and lumpfish, prized for their roe.
The study also found that around 6,600 tonnes of capelin were used as bait between 1950 and 1992 without being recorded in official catch reports, contributing to the depletion of a species that once played a central role in local fisheries and culture.
“Artisanal fisheries, however, did not go back to fishing cod after the moratorium, instead focusing on snow crab and lumpfish, the latter exploited for its roe,” Fabrice Teletchea, co-author of the study and associate professor at the University of Lorraine, told Phys.org. “They also catch a bit of capelin, but not as much as they used to between 1950 and 1992. Capelin was mostly kept by fishers themselves to consume at home or to use as bait.”
As artisanal fishers shifted away from cod, industrial fleets also diversified, targeting species such as sea cucumber, American lobster, northern shortfin squid and Atlantic deep-sea scallops within the Saint Pierre and Miquelon Exclusive Economic Zone (EEZ). Researchers said the growing focus on marine invertebrates reflects a broader shift in local fisheries following the collapse of cod stocks.
Researchers found that fisheries have increasingly shifted from large predatory fish such as cod, haddock and redfish to lower-trophic-level species, a trend that Daniel Pauly, co-author of the study, described to Phys.org as “fishing down the marine food web.”
He warned that the loss of apex predators could disrupt food web dynamics and weaken ecosystem resilience, while growing pressure on invertebrate stocks, particularly sea cucumbers, could lead to overexploitation and make these fisheries environmentally and economically unsustainable without comprehensive management.