Are you one of those people that, probably out of pandemic-related boredom, has typed your name into the Google search engine just to see what pops up?
Have you ever found anything interesting? Any nomenclature doppelgangers out there with your name walking around doing interesting or absolutely bizarre things?
Now, what happens if you enter the words cod collapse into the world’s most used search engine?
The top entry that emerges is a Wikipedia post entitled “Collapse of the Atlantic northwest cod fishery.”
This is just another example of how infamous the perception is of the late 20th century demise of the Northern cod fishery that occurred right off our shores. Despite all of the groundfish stock challenges taking place around the globe, the words cod collapse appear to be synonymous with the tumultuous events of the late 1980s and early 1990s preceding the 1992 moratorium.
According to the Wikipedia post, “a significant factor contributing to the depletion of the cod stocks off Newfoundland’s shores was the introduction of equipment and technology that increased landed fish volume. From the 1950s onwards, new technology allowed fishers to trawl a larger area, fish more in-depth and for a longer time. By the 1960s, powerful trawlers equipped with radar, electronic navigation systems and sonar allowed crews to pursue fish with unparalleled success and Canadian catches peaked in the late-1970s and early-1980s. Cod stocks were depleted at a faster rate than could be replenished. The trawlers also caught enormous amounts of non-commercial fish, which were economically unimportant but very important ecologically. This incidental catch undermined the stability of the ecosystem, depleting stocks of important predator and prey species.”
As is evident by the Wikipedia post, the overfishing by trawlers, along with stock mismanagement by Department of Fisheries and Oceans (DFO) scientists, has long been associated with causing the collapse of what once was the world’s largest cod fishery. And in speaking with fishermen who lived and worked through the moratorium years, there is a lot of evidence to back up those assumptions.
But after decades of limited fishing, why has the once prolific cod stock not bounced back?
One of the theories that has emerged in recent years as to why Atlantic cod stocks, notably in 2J3KL, have not witnessed more improvement, involves evolution.
Many debates over the last few decades have focused on whether cod have evolved in response to fishing activity, a phenomenon known as fisheries-induced evolution. Studies have shown that cod now mature at a much earlier age. The concern has been that if the fish have evolved, they may not be able to recover even if fishing is reduced.
It is believed that cod populations with late-maturing individuals can produce more offspring and more effectively avoid predators. They are also better protected against climate variability, more stable and are less likely to collapse.
However, a study released earlier this year by Rutgers University and the University of Oslo is suggesting that overfishing likely did not cause the Atlantic cod to evolve genetically and mature.
“Evolution has been used in part as an excuse for why cod and other species have not recovered from overfishing,” said first author Malin L. Pinsky, an associate professor in the Department of Ecology, Evolution and Natural Resources in the School of Environmental and Biological Sciences at Rutgers University-New Brunswick.
“Our findings suggest instead that more attention to reducing fishing and addressing other environmental changes, including climate change, will be important for allowing recovery. We can’t use evolution as a scapegoat for avoiding the hard work that would allow cod to recover,” he told Rutgers Today.
The study, which appeared in the journal Proceedings of the National Academy of Sciences, focused on Atlantic cod (Gadus morhua) off Newfoundland in Canada and off Norway. In the Northwest Atlantic Ocean, cod range from Greenland to Cape Hatteras, North Carolina. Cod can reach 51 inches long, weigh up to 77 pounds and live more than 20 years.
“Both theory and experiments suggest that fishing can lead to an earlier maturation age. But prior to the new study, no one had tried to sequence whole genomes from before intensive fishing to determine whether evolution had occurred. So, scientists sequenced cod earbones and scales from 1907 in Norway, 1940 in Canada and modern cod from the same populations. The northern Canadian population of cod collapsed from overfishing in the early 1990s, while the northeast Arctic population near Norway faced high fishing rates but smaller declines,” the study reported.
“We found that cod likely did not evolve in response to fisheries,” Pinsky said.
“There were no major losses in genetic diversity and no major changes that suggested intensive fishing induced evolution. We cannot entirely rule out that evolution happened, but it’s more likely that the fish are developing earlier as a response to their environment and would be able to develop and mature later if the environment changes, benefiting the species.”
The scientists’ findings complement conclusions from literature reviews and evolutionary modeling that the direct impacts of fisheries on populations and ecosystems are a more pressing concern than the effects of fisheries-induced evolution, the report explained. However, avoiding overfishing and reducing fishing pressure when populations become low remain a key management strategy.
So, does this study shed any more light on the reasoning why, according to government scientists, cod stocks are not recovering faster off our shores? Maybe. But it does emphasize a key point — there is still much important work to be done into groundfish stocks off our coastline. Work that has to involve all stakeholders — most importantly, those closest to the resource, the harvesters on the water.
If the voices of the fishermen were heeded decades ago, we might not have found ourselves in this position today. But that is another contentious topic for another day.
For now, all hands should be following the advice of Albert Einstein when he said, “We cannot solve our problems with the same thinking we used when we created them.”
