As the global population continues to rise—and with it the demand for food—increasing pressure is being placed on our oceans. The saying goes, ‘there are plenty of fish in the sea,’ but the abundance of seafood in our supermarkets is deceptive. 

According to the Marine Stewardship Council (MSC), global seafood consumption has increased by 21 per cent between 1992 and 2002. In 2000, roughly 90-100 million tonnes of fish were extracted from the world’s oceans. This represents a five-fold increase since 1950. As long as the demand for fish remains high, fishing will continue to be a lucrative industry.

Global awareness of overfishing is growing. Lauren Chapman, Canada Research Chair in Respiratory Ecology and Aquatic Conservation, and professor in McGill’s biology department, said that “It’s not just that we’re targeting one population or one species, it’s that this is a world-wide global phenomenon.” Chapman explained “We’ve got [an] over 90 per cent decline in many of the large predators like the tuna and the sharks. And you can imagine what that does to the ecosystem.”

As the Greenpeace website states, bluefin tuna, a high market value fish, continues to be fished despite warnings from scientists.

Chapman investigates the ecological and evolutionary consequences of environmental stressors such as overfishing, and how organisms respond to these stressors by becoming extinct, by moving to new habitats, by going through a genetic change, or through a plastic response. “Plastic variation is when there’s a change in the traits of the individual that’s induced by the environment,” Chapman explained. “[For example] if you’ve grown up on a very poor diet you might end up smaller, skinnier or whatever, but it’s environmentally-induced change.”

“When you are selectively fishing populations, you’re often selecting the largest, fastest growing individuals. … So there’s a growing awareness that this heavy fishing that we’re doing—it could be in marine systems, could be in freshwater systems—is leading to changes in the characteristics in the fish themselves,” Chapman said.

Fish populations often respond to heavy fishing by reproducing at a smaller body size and maturing at a younger age. However, it’s very difficult to discern whether or not this response has a genetic basis to it, or if it is a plastic change. 

Plastic change is not as severe as genetic change. As Chapman noted, “[if] we put a moratorium on [a] fishery, it may take a long, long time, if there has been genetic change, for that to be reversed.” Also, she warned that in some cases it is very problematic to try and reverse these trends. However, while we might not necessarily be able to return to the situation from which we started, there is still a good direction to move towards.

In Canada, the story of the Atlantic cod fishery in Newfoundland is an example of too little too late. According to Greenpeace, by 1992 Atlantic cod stocks collapsed due to overfishing. In response to the stock declining by 99 per cent, the government imposed a moratorium, effectively shutting down the Newfoundland cod fishery. This caused the displacement of tens of thousands of workers, devestating communities who relied on the fisheries for their livelihoods. Despite these efforts, the fish stock has yet to see any recovery.

As the cod fishery example demonstrates, many jobs and livelihoods depend on fishing. According to the MSC, around “200 million livelihoods depend directly or indirectly on the fishing industry.” This is particularly pertinent in the developing world, as it is the source for half of the seafood traded worldwide. Not only does fishing provide jobs, but as the MSC says on their website, one billion people worldwide depend on fish as their primary source of protein. And so, while the effects of overfishing will essentially jeopardize this food source and the jobs it creates, the short-term pressure of earning an income and having food to eat will keep this industry in motion.

William Agnew, a recent graduate from the McGill School of Environment, was involved in an in-depth study conducted for McGill Food and Dining Services (MFDS) with regards to developing a system that enabled MFDS to make sustainable seafood purchasing decisions. Agnew explains that there are four types of fish that are severely threatened by overfishing. These include cod, bass, salmon, and tuna, all of which are fished in a unsustainable manner. “But there are also ways of procuring those products or those species in a more sustainable way. And it can come right down to just the way it’s fished, and where it’s fished,” Agnew explained.

The trouble is, “the actual definition of what sustainable seafood is doesn’t really exist … everyone sort of has a different [definition],” Agnew said. In their executive summary of the project, Agnew and his colleagues defined sustainable seafood as “seafood fished or farmed in a socially responsible manner that does not jeopardize the long-term health of any species in the associated ecosystem for generations to come.”

“It will require very careful management and intervention to keep it sustainable,” Chapman said. Choosing to eat larger fish, such as tuna, as opposed to smaller species, doesn’t mean the smaller species go unharmed. It is a cascading effect. Chapman explained that, when looking at a system such as Lake Victoria in Uganda, or Lake Erie in North America, “you see that people start off fishing the largest, fastest growing fish. Then [those fish] disappear, and fishers are very adaptive so they move down to the next part of the food-chain, the smaller fishes. … So, the fishers may be taking out the same amount of fish, but they’re taking out more smaller fish, and then [the fishery] can collapse very easily.” This is known as fishing-down.

“You can fish down a species [by] fishing the largest fish, then the smaller fish and then the smaller fish. You can also fish down a community,” Chapman said. Tied to this is the concept known as the tragedy of the commons. This occurs because the oceans are a global commons; they do not belong to one government; they are a shared resource. Each fishery is concerned with making a profit, which causes them to fish as much as possible. Theoretically, the more fish you catch, the more money you make. The irony is that with each individual fishery acting on the same motive, as a collective they will damage the commons upon which they rely.

“There’s a lot to be overcome when you’re dealing with waters that cross [many] political boundaries,” Chapman said. It is important to note as well, that it is not just the fault of the country doing the fishing, but of those countries willing to purchase the fish as well. “If you have an export market that’s willing to take undersized fish, it’s really hard for the country [providing the fish] to impose regulations,” Chapman said. 

Agnew explains that the idea of sustainable seafood in Montreal is a novel one. “In Montreal, I can’t go into a fishmonger’s anywhere and ask for sustainable seafood, they’ll just give you a strange look,” he said. However, with MFDS’ commitment to serving only sustainably seafood as of Sept. 1, 2010, he remains optimistic. When it comes to purchasing sustainable seafood in your local grocery store, however, Agnew advised consumers to look for the Marine Stewardship Council certification. When compared to other certification systems out there, Agnew said “It’s as rigorous as it gets, and it’s widely available.”

The MSC focuses on wild fisheries. Using the scientific research that comes out of the Monterey Bay Aquarium, the MSC looks into what quantities of fish are less likely to damage the fish stock. They also investigate the methods used to catch these fish. One
of the most harmful methods of fishing is trawling, which scrapes the seabed, both destroying the ecosystem as well as producing incredible amounts of bycatch. Bycatch refers to the species brought up on deck that are not what the fisheries were looking for, and are killed through the fishing process. 

The MSC estimates that around eight per cent of all fish caught annually by marine fishers is bycatch. This equals almost seven million tonnes of fish per year that are discarded back into the oceans by commercial fishermen across the globe. “The MSC encourages using more species-specific methods of catching fish. Hook-and-line is a very good way,” Agnew said. 

With the MSC certification process taking up to two years to complete, it can be very difficult for companies to become fully certified immediately. Agnew advised  consumers: “When you see a company that says they’reMSC certified, don’t assume that all of their products are sustainable MSC certified. It’s usually just a few products that are certified. You need to look for the MSC logo on the final product.”

Agnew also warned about fragmentation. “There are definitely a lot of eco-labels [and] companies out there that put on this face of sustainability,” he said. However, there are also companies out there whose sustainability efforts may be surprising. Agnew reveals that McDonalds is in the process of getting their fish sandwiches MSC certified. “In fact, McDonalds is a fast food industry leader in terms of sustainable seafood, believe it or not,” he said.

Consumers should also be aware that over half of the fish in supermarkets come from aquaculture, or fish farms. Many assume aquaculture to be “a great answer to the [overfishing] issue…but it can be incredibly ecologically harmful and it often uses feed that is fish from the ocean,” Agnew explained. Currently the World Wildlife Fund is  in the process of producing aquaculture standards to regulate the relatively new industry. 

Chapman stressed that it is important to catch the fisheries before they reach their tipping point, because there is still potential to reverse the trends induced by overfishing. “The best thing is to encourage people to be a little more aware and that what they’re eating might really be some of the last,” Agnew said, “It’s amazing to think that a resource as large as our oceans could ever dry up.”

 

Fish facts

Look for this MSC label on the seafood in your local grocery store. This label indicates which seafood is MSC certified.

Salmon farms sometimes use pesticides and antibiotics to control outbreaks of disease among the fish. When consumers eat farmed salmon, they may also be eating residue from the chemicals used by the farms.

Bluefin tuna is the world’s most valuable fish for sushi 

Next to overfishing, climate change and ocean acidification are the greatest threats to marine biodiversity

Pirate fishing (illegal, unreported or unregulated fishing) accounts for one quarter of the world’s total catch of wild fish.

The global oceans have lost an estimated 90 per cent of their large predators

Tip: Download the MSC pocket guide next time you want sushi. It will tell you which types of fish are fished sustainably

Scientists have estimated that in Canadian waters, marine fish species have suffered a 52 per cent decline since the 1970s.

Best alternative to Atlantic cod: Cobia (U.S. Farmed)

Best alternative to Salmon: Arctic Char (Farmed in Recirculating Systems)

Best alternative to Tuna: “White” Canned Albacore (Troll/Pole from the Canadian and U.S. Pacific) or “Light” Canned Skipjack (Troll/Pole)

The export value of world trade in fish was U.S. $63 billion in 2003. This is more than the combined value of net exports of rice, coffee, sugar, and tea.

Half of the seafood traded worldwide comes from developing countries

The UN predicts another 2 billion people will join the world’s population within 20 years.

One-quarter of the world’s fish stocks are overexploited, depleted, or recovering from depletion. About half of the stocks are fully exploited.

Sources: Marine Stewardship Council, Greenpeace, Monterey Bay Aquarium