The glorious, sharp-toothed, bearded-mouthed creatures have ruled the oceans for tens of millions of years, some even before dinosaurs walked the land. Throughout marine history, sharks, rays and whales have captured humanity’s curiosity and fear.
In our exploration of the oceans, we have studied these animals in hopes of understanding their behaviors and environments. However, we also captured and killed them along the way. Often, this is not only a detriment to the animal but to the entire ocean ecosystem.
Many species of large fish and marine mammals are currently endangered, with more than 41,000 species facing extinction. Amidst controversial issues of animal captivity, fishing and climate change, conservation scientists, animal keepers and the global community must address the threat of extinction facing these creatures.
The dangerous reputation of cetaceans (whales, dolphins and porpoises) is a result of their role as predators in marine food webs. Susha Fountain, an educator at Ripley’s Aquarium in downtown Toronto, teaches about shark and ray (or “elasmobranch”) conservation.
In an interview with The Medium, he describes how the placement of elasmobranchs as “high trophic level predators in their communities is important for maintaining ecosystem homeostasis.” He explains that their position at the top of the food chain is key to the stability of the ecosystem despite environmental changes. When these top predators start to disappear, it disrupts the rest of the ecosystem.
University of Toronto Mississauga (UTM) professor and avid whale fan, Professor Christopher Richter agrees with Fountain. When whale populations decline, Professor Richter explains, the impact can be seen in fluctuations all the way up the food web, all the way to seagrass populations.
Professor Richter points out how “we are only just beginning to appreciate the importance of whales in contributing to the idea that the oceans are a carbon sink. [oceans store and absorb carbon dioxide].” Because large species such as blue whales sequester carbon in their bodies even after they die, they play a role in fighting rising atmospheric carbon levels. This carbon is further recycled into deep-sea communities when whale carcasses begin to decompose, a phenomenon called “whale fallout.”
Having researched sperm whales during his Ph.D. at the University of Otago and porpoises during his Masters at Memorial University of Newfoundland (MUN), Professor Richter studied how their populations are affected by the activity of human: the main threat facing elasmobranchs and cetaceans.
Fishing, for example, presents many problems. During the first project that Professor Richter worked on at MUN, he observed that “in the Bay of Fundy, small marlins are caught in cod gill nets. […] Because they’re so close to the bottom, they suffocate, they can’t come back to the surface.” This bycatch (a term for animals accidentally caught by fisheries targeting commercial species) has impacts beyond porpoises.
In addition to bycatch, abandoned fishing gear poses pollution problems that can be fatal. Known as “ghost gear,” Professor Richter explains that buoys, nets and lines made primarily of nylon and metal “don’t disintegrate; they’ve been out there for years.
But [the gear] he keeps fishing and no one takes them out, or at least not in a systematic way”. For animals that feed on the surface, such as the iconic Canadian right whale, whose population has dwindled to 350, this plastic pollution can be harmful.
Historically, the fishing industry has caused the greatest threat to these large fish and mammal populations: the sperm whale populations studied by Professor Richter are still recovering from hundreds of years of whaling, also known as hunting of whales However, in recent decades, more complications have arisen.
Fountain explains that for sharks and rays, climate change threatens to leave many species homeless. “Coral reefs only make up about 1% of the ocean floor, but they host about 25% of marine biodiversity. […] The loss of these habitats affects the entire community, but it is most visible in shark and ray species because these high trophic level species need to consume more energy,” shares Fountain.
For example, Fountain points to the presence of basking sharks reef as a general indicator of a healthy reef because it means that the ecosystem is meeting the high levels of productivity they require.
The fountain is uniquely positioned as an expert in marine biology and conservation by studying and educating people about conservation and the environment while working at Ripley’s Aquarium of Canada. The conservation of marine species is as complicated as the ecological networks they try to preserve.
Professor Richter comments that “even though we might be sitting here by Lake Ontario, far away from the ocean, regardless, what we do has an impact on [marine organisms].”
While aquariums and zoos have a somewhat controversial reputation, they also support conservation research, advocacy, and education. The dichotomy in question is “What is the trade-off?” Professor Richter asks: “Is it worth removing an animal not only from its habitat but also from its social environment?” Both Fountain and Professor Richter agree that most zoological societies, such as Canada’s accredited zoos and aquariums, consider cetacean captivity to be inhumane.
Professor Richter states that “the bottlenose dolphins [and] killer whales are social. And we know that removing people from these groups has an impact on the rest.” So, although it is not as quantitatively harmful to populations as fishing, captivity still raises important concerns. “Being a teacher, education always it’s a solution or part of the solution. So I think zoos and aquariums have a role,” says Professor Richter.
Even without displaying these species, aquariums can have a positive impact by talking about cetaceans, other non-captive species and the threats they face. “The most important thing to keep in mind,” adds Fountain, “is that we are respectful of animals in the wild and in captivity.”
A few weeks before Professor Richter’s interview on The Medium, UTM hosted a screening of the documentary The Last of the Right Whales (2021), where Professor Richter participated in the panel discussion. The documentary focused on the struggle of a marine biologist, a whale rescuer and a wildlife photographer to protect endangered right whales from widespread ghost fishing.
Following the release of the film in 2021, with their passion and hard work, and urging viewers to support the Right Whale Coexistence Act, the government passed legislation, addressing the traffic of phantom equipment, fishing and shipping in the North Atlantic region on the right. the whale room in February 2022. “They showed what we can do as a nation,” says Professor Richter. “If we show our government [that] right whales are important to us because they are a symbol of how we treat the oceans, we can make it a priority,” he continued. That we do so is not just a matter of the future of whales, sharks or any marine organism, but the future of the ocean and, by extension, our future.