On a field trip to see salmon runs on the Humber River as a Master of Environmental Science student at UTSC, I felt slightly unsettled and surprised. As the salmon ambled upstream, our professor was talking about the river’s ecological condition and invasive species in the region. 

Sea lamprey is one of these destructive invasive species in Lake Ontario. The GLFC reported that at one point before the 1990s, sea lampreys killed more than 100 million pounds of fish in the Great Lakes in a year. To control the species, the Great Lakes Fishery Commission (GLFC) traps sea lampreys in sections of the Humber River so GLFC workers can capture and kill them, and uses lampricide poisons to kill sea lamprey larvae. I was shocked that killing en masse, justified or not, was a common and accepted conservation practice. 

With large-scale campaigns to save endangered species, conservationists are often at the forefront of protecting animals and species at risk. Conservation biology emerged as a discipline to address and prevent extinctions humans have caused through habitat destruction. For example, conservationists often work to restore landscapes degraded by humans, which, in turn, allows many species to thrive. 

However, any straightforward impression of conservation protecting all animals comes apart. In many cases, conservation efforts may harm specific animals — such as when the GLFC kills sea lampreys en masse — while protecting biodiversity and habitats, and we have to decide which cases of such harm we should allow. Compassionate conservationists argue we should prioritize animal welfare concerns, while other ecologists highlight the detrimental nature of invasive species and how managing ecosystems is an urgent matter.

Managing wildlife and ecosystems

One key problem in conservation is invasive species. Invasive species are organisms not native to an ecosystem that cause significant ecological, economic, or societal harm. Often, they reproduce quickly and lack natural predators in their new environment, which allows them to outcompete native species and makes it more difficult for endangered species to persist. 

Although there has been controversy around classifying and treating organisms as invasive and native, one survey by Shackleton and colleagues published in 2022 of nearly 700 scientists and practitioners working in invasion science found that its respondents generally agreed that invasive species pose a major global biological threat. Consequently, conservationists dedicate great efforts to preventing the introduction of new species into novel ecosystems and controlling existing invasive species. In Ontario alone, the Invasive Species Centre estimates that the government spends $50.8 million annually managing invasive species. 

When it comes to reducing the numbers of invasive species such as sea lamprey, there are several nonlethal and lethal ways conservationists use to reduce the species’ numbers and the ranges they inhabit. With sea lamprey, for example, one nonlethal way to minimize their population is by building barriers and dams that prevent them from migrating upstream and spawning. Currently, the GLFC reports that there are around 70 such dams in the Great Lakes

For invasive species that have already established themselves in the new ecosystem, the main mechanism conservationists use to control them is killing them. For example, the GLFC treats tributaries with lampricide to kill larval sea lamprey. The lampricide compounds disrupt the metabolism of larval lamprey without significantly harming other species. 

Nicholas Mandrak, a professor at the Department of Biological Sciences at UTSC, explained in an interview with The Varsity that for larval sea lamprey affected by lampricide, researchers likely don’t have “any idea about whether or not they’re going through pain and suffering.” 

Additionally, land managers capture juvenile and adult sea lamprey in traps placed along tributaries. Mandrak said that the captured sea lamprey are then put in “for lack of a better term… a dump truck” where researchers “just let them die, basically, by lack of oxygen, being out of the water.”

Conservation practices can also harm animals when conservationists are not trying to reduce population numbers, such as in the process of reintroduction or translocation. When animals are reintroduced into an area where they went extinct, they often suffer from high mortality rates due to human-related environmental disturbances, stress, and predation. One study that reviewed 45 carnivore reintroductions found that only 32 per cent of captive-born animals survived reintroduction, which is 18 per cent lower than the survival rate for wild-caught animals reintroduced without conservationists raising them in captivity. 

Conservation practices can have a large human impact as well. In a paper in BioScience, researchers Peter Kareiva and Michelle Marvier emphasized that conservation science is not only guided by the goal of biodiversity — people’s livelihoods and ethical values are also key, oft-neglected components of conservation.

Journalist Mark Dowie wrote that estimates for the number of conservation refugees — Indigenous peoples forced off their land in the name of land and wildlife conservation — range from five million to tens of millions. In Botswana, the San people — an Indigenous people of Southern Africa — have been systematically stripped of their land to make way for the Central Kalahari Game Reserve and to prevent them from hunting. The displacement of Indigenous communities often comes with the tacit approval or silence of large nonprofit conservation organizations.

The research impact

On a personal level, researchers feel pressure about the harm their research can sometimes cause. Rachel Bryant, a former philosophy assistant professor at UTSC and current assistant teaching professor at the University of Tampa, remembers her experience working on seabird research vividly. In an interview with The Varsity, she recounted a particularly memorable experience when she was working with terns. “There was a gull… who was depredating a lot of terns. Some [of the terns] were species at risk, and we were told by our boss to kill the gull… and I’ve never gotten over it.” 

Even though killing the gull might have been necessary for conservation research and have positive effects overall, Bryant felt bothered by the distress she caused for the gull, and for potentially disrupting the gull’s breeding seasons.

Current Ontario law requires individuals to kill any prohibited invasive species they come into contact with. For example, with round goby, which threatens several endangered species, Mandrak said that Ontario requires individuals to “remove [round goby] from the [water] system… If a recreational angler catches a round goby, they are supposed to dispose of them.” 

Ontario does not explicitly discuss “humane euthanasia,” according to Mandrak. The GLFC also makes no explicit mention of animal welfare considerations when discussing practices to reduce sea lamprey populations.

The lack of consideration for animal welfare is also evident in practice for land managers and municipalities dealing with ecological challenges. In Winnipeg, because people have released their pet goldfish in local ponds, goldfish are becoming hyperabundant in urban lakes, which prevents the city from effectively managing stormwater flow. Winnipeg manages this problem by draining stormwater ponds at the end of the summer and letting the goldfish in them die through that lack of water. 

Mandrak said, “I [argue] that it’s probably the right thing to do. But it could be done more humanely.” As a researcher studying the effect of invasive aquatic species, Mandrak often captures invasive species either to study them or as bycatch — when a species is unintentionally captured. When handling animals, all academics in Canada have to adhere to the guidelines of the Canadian Council on Animal Care (CCAC), which outline minimum animal welfare standards. At U of T, the university’s Animal Care Committee implements and oversees CCAC’s guidelines and provides permits for approved research procedures involving animals.

Compassionate conservation 

One attempt to fold animal welfare concerns into conservation is the growing compassionate conservation movement that pushes for conservation where we extend compassion to animals and humans. In an article in the Journal of Conservation Biology in 2018, Arian D. Wallach and other ecologists wrote that compassionate conservation works to preserve the Earth’s biodiversity while “retaining a commitment to treating individuals with respect and concern for their wellbeing.” 

One of their key tenets is that conservationists should first “Do No Harm” and step back to assess their possible courses of action rather than acting immediately. Other tenets of compassionate conservation include how individual animals matter, where individual wild animals should not be valued solely as members of species, and how conservation should be about “the manner in which we ought to engage with the world.” Lastly, they also believe that all wildlife are intrinsically valuable regardless of their population size, origins, sentience, or usefulness to humans. 

Sometimes, these tenets work. In Middle Island, Australia, fox predation caused the population of Little Penguins to decrease from over 500 to 10 penguins in five years. To reverse this decline, in 2006, researchers used Maremma guardian dogs to protect the colony and successfully prevented fox predation. After 10 years, the population of Little Penguins increased to over 100. Given that the previously-used conservation strategy of trapping foxes was ineffective to begin with, the successful reduction of fox predation on little penguins with sheepdogs was an example of an ideal, win-win scenario. 

Similarly, advocates in South Africa ran educational campaigns for farmers on nonlethal ways to control leopards predating on livestock. These campaigns led to an approximately 70 per cent decline in leopard predation rates on livestock while reducing the operating cost of caring for sheep for those farmers. 

Researchers like Wallach say that the tenets are aspirational goals for how we should engage with wildlife. In practice, these guidelines do not provide clear-cut answers on which control strategies, if any, conservationists should take. 

A balancing act 

It is easy for everyone to get on board when it is economically and ecologically advantageous to use nonlethal, non-invasive conservation tactics. However, that’s not always the case. Mandrak stresses the importance of preventing invasive species from entering new ecosystems, given his doubts that “there [are any measures] that [are] effective once they’re established.” It is important to prevent detrimental species from entering new habitats, which can mean killing said species when they are first spotted. 

Grass carp are an example of the problems conservationists can cause by delaying action. Instead of immediately killing and removing grass carp, Mandrak described how Ohio’s government tagged and studied the fish to see where they would spawn. Though it found the species’ spawning locations, its tagging program meant it didn’t take quick enough action to stop that spawning. 

Time is of the essence when trying to mitigate the effects of detrimental species. If grass carp establish a population in the Great Lakes, an ecological risk assessment conducted by Fisheries and Ocean Canada found that they could have high negative impacts on 33 fish species and a moderate negative impact on another 33 fish species. If we take no action against a potential invasive species, the establishment of that species could mean that more animals are harmed by the invasive species’ disruption to existing food webs.

Other cases of wildlife management are also less straightforward. When individuals release their pet goldfish into local ponds, they face “their own little mini animal rights issue” where “they don’t want to flush the pet goldfish down the toilet,” said Mandrak. However, those individuals either neglect or are unaware that introducing such goldfish can end up causing more harm to animals and ecosystems.

Additionally, more often than not, the connection between a decline in an invasive species’ population and the ecological benefits of biodiversity or native species growth rates is unclear. One study by Kim M. Pepin and colleagues published in 2017 on the effectiveness of culling in reducing wild pig populations cautions that the relationship between ecological harm and wild pig abundance is not well established. The relationship might not be linear, where more culling would correlate with a decline in ecological harm. 

Researchers estimate that the relationship is more complicated: the decline in the pigs’ population numbers needs to meet a certain threshold before we see ecological benefits. If such is the case, then if we employ culling below the necessary threshold level, those actions would provide little benefit to the environment at the expense of those animals. Researchers have also found that unpredictable environmental events, such as hurricanes, can also change the effectiveness of culling. 

Recognizing difficult ecological decisions

Policymakers, conservationists, and scientists have to make challenging decisions that will often harm animals. Bryant describes these scenarios as tragic conflicts. 

“In some cases, it seems like no matter what we do, we’ll wrong somebody — either they’re members of the species that are endangered that we’re doing this to protect or the individual animals who we’re harming in order to prevent those extinctions,” they said. “And so that’s why I think that [these scenarios are] tragic. A tragedy is a story in which there can be no good ending.”

Calling these scenarios tragedies is a way of highlighting the difficult decisions involved with wildlife management. Bryant said, “Calling it a tragedy reminds us that we can’t just get off the moral hook for doing the things that create these situations. [We often] suppress and are dishonest with a part of ourselves when we don’t acknowledge the moral complexity [of our actions].” 

Bryant said, crucially, we should “stop creating the situations that make it be that a species is going extinct and the only way to save it is to harm individual animals.” Avoiding these situations means addressing climate change and minimizing environmental degradation. 

The next step for conservationists is to figure out which actions would be most ecologically beneficial while also minimizing the harm to animals. Bryant also acknowledges, however, that conservation makes up a small portion of the suffering animals experience. “If you really want to stop the human-caused suffering of animals to the extent that you can, it’s factory farming that we should be focusing on… that’s where most of it is happening.” 

The boundaries of conservation

Critics of integrating animal welfare concerns into conservation, like ecologist Peter Fleming, say that this kind of thinking is “animal liberation dressed up as conservation science” and “has little foundation in biology.” These critics speak to the tension that exists in wildlife management — respecting animal rights is sometimes at odds with protecting habitats and other species.

In some cases, prioritizing animal welfare very well could mean that we are less effective at fostering biodiversity and saving a species — and those ecological concerns are often pressing. If we don’t act now, the ecological harm invasive species cause might be irreversible or incredibly costly to reverse later. Consequently, some scientists want to exclude animal welfare concerns from conservation management and research. 

However, these concerns don’t have to restrict research. When Mandrak’s lab captures fish, they go beyond Ontario’s requirements by euthanizing the fish in a way that minimizes their pain and distress. Although this euthanization takes more time, money, and planning, Mandrak finds that it is not prohibitive to their conservation work. 

Concerns to respect animal rights are also in line with key principles of conservation, Kareiva and Marvier pointed out in their paper. As ecology embraces equity and justice, they wrote that “conservation must not infringe on human rights and must embrace the principles of fairness and gender equity… Obviously, life is not always fair, but conservationists should not make it less so.”

This understanding of conservation science highlights that conservation is often rightfully bound by other concerns that are not directly connected to ‘biology.’ If we think that the suffering of animals is unjust and that the rights of animals matter in the way that rights matter to humans, then it is within the realm of conservation.