Double-crested cormorants don’t have a lot of fans.

Standing as tall as the average toddler, they have distinctive S-shaped necks, dark plumage and orange skin around their beaks. They sometimes vomit when threatened. Their acidic feces — called guano — kills vegetation on the islands and shorelines they settle, stripping trees bare until they look like bones. Cormorants also eat a lot of fish, and anglers have long viewed them as competition.

“They have a long history of people not liking them,” said Gail Fraser, a professor in the faculty of environmental and urban change at York University who has studied cormorants since 2006.

“Literally, centuries of that.”

The latest form of that dislike is a new fall hunting season, announced by the Ontario government on July 31, which will allow hunters to bag 15 cormorants per day from Sept. 15 to Dec. 31. In its announcement, the province framed hunting cormorants as a means of protecting local fish stocks and ecosystems.

“We've heard concerns from property owners, hunters and anglers, and commercial fishers about the kind of damage cormorants have caused in their communities, so we're taking steps to help them deal with any local issues,” said Minister of Natural Resources and Forestry John Yakabuski in a July 31 statement.

The reality is more complicated than that, experts and advocates say: cormorants are native to Ontario, recorded in Lake of the Woods as early as the 1790s. Eagles (yes, the province has eagles) like to eat them, and cormorants are a vital part of a balanced ecosystem. Some studies have shown that cormorants tend to feast on invasive fish species, rather than the ones humans like to eat. Other types of birds prefer to nest near them, Fraser said.

Cormorants are also a conservation success story in Ontario, having bounced back after a dramatic decline in the late 20th century.

Critics question the science behind the hunt, with some saying it lacks proper population targets and the bag limit is too high. Some also say the cormorants have been unfairly maligned, and that there are better ways to control the population.

Still, others point to concerns about the impact cormorants can have on ecosystems. In southern Ontario’s Point Pelee National Park, for example, cormorants have been culled in an effort to protect rare species officials say were threatened by cormorant guano.

It’s common for governments to control populations of native species when they begin to disrupt normal biodiversity — deer are one example, said Lauren Tonelli, a resources management specialist with the Ontario Federation of Anglers and Hunters (OFAH).

A lot of people don’t like cormorants and the bone-like trees they leave behind. But experts and advocates question whether the Ford government’s new cormorant hunt is based on science. #onpoli

“We’re not looking for any species to get wiped out,” Tonelli said.

Jolanta Kowalski, a spokesperson for the Ontario Ministry of Natural Resources and Forestry, said in a statement that the province has a healthy population of cormorants, and the hunt isn’t expected to change that.

“We will continue to monitor the cormorant population status and trends to support sustainability of cormorants in the province,” she said.

Cormorants nest in trees that have been stripped by their guano at Tommy Thompson Park in Toronto in 2011. Photo by Matthew Fells/Flickr

A conservation victory

In the 1960s, double-crested cormorants started vanishing rapidly from the Great Lakes.

Suffering from the effects of the toxic pesticide DDT, the contentious birds’ eggs had become so thin that they’d crack under the weight of adults incubating them, killing the embryos. By the early ’70s, just 130 nesting pairs were recorded on the Great Lakes, with the birds completely absent on the American side. Some states south of the border listed cormorants as endangered.

“There’s a whole generation of people that never saw cormorants while they were out on the water,” Fraser said.

As public awareness about the effects of DDT grew and stricter regulations came in, use of the chemical decreased and cormorants began to recover. Their populations exploded in the ’90s, and they began populating the Great Lakes once more.

That was about the time OFAH started raising concerns about the birds, Tonelli said. “A lot of our members were noticing that the islands and shorelines where cormorants roost really started to die off after a few years of cormorants being there.”

“We started pushing the government to do their own control program,” she added. “What they decided to do instead was to institute a — I hesitate to call it a hunt, it’s more of a cull.”

The Ontario government first proposed the hunt last year. (OFAH supported the idea, although Tonelli said the group would have preferred a different approach.)

Even with some modifications in response to public feedback, the plan is deeply flawed, said Fraser, who also said it amounts to a cull. If 1,000 hunters took home the bag limit of 15 cormorants per day for 10 days, they’d be killing 150,000 birds. That’s more than the breeding population of 143,000, which the province identified through monitoring last year.

About 285,000 people currently hold the small game licence they’d need to hunt cormorants, according to the Ministry of Natural Resources and Forestry. (The same licence also allows hunting of other animals, such as rabbits and grouse.)

“That is not sustainable,” Fraser said.

Tonelli said that kind of math is unrealistic — there are a lot of cormorant habitats, such as provincial parks and municipal shorelines, where hunting isn’t allowed. The birds will also likely scatter and fly away if hunters are shooting at their colony, she added.

“The chance of someone actually shooting 15 cormorants per day for the entirety of the season is almost nonexistent,” Tonelli said.

“We really see this season, especially since it overlaps with waterfowl season, as a way for people who are already out waterfowl hunting to maybe remove a few cormorants while they’re out.”

Fraser also said she’s concerned that the government doesn’t appear to have set population targets for cormorants. Such targets exist for other game, such as deer.

“It’s not good natural resource management,” Fraser said.

The province didn’t provide targets or explain the lack of them when asked by Canada’s National Observer.

“Combined with historical data, trends suggest that cormorant populations are increasing in Lake Ontario, Lake Erie, and Lake Superior and are stable on the St. Lawrence River and Lake Huron,” Kowalski said in the statement.

Gail Fraser, a cormorant expert and professor at York University, said she's concerned the Ford government's plan for a cormorant hunt is deeply flawed. Photo courtesy Gail Fraser

‘I don’t know what purpose that serves, killing a bunch of birds’

Government staff have also pushed back against the cormorant hunt, CBC News reported last year. After an earlier version of the plan was proposed in 2018, one report author said the idea that a cormorant hunt would improve commercial or recreational fish stocks was “not supported by science,” according to documents obtained by CBC.

Multiple studies have shown cormorants primarily eat invasive species, rather than salmon or walleye.

Kowalski said “a number” of staff concerns were resolved in the government’s final proposal.

“The potential impacts to local fish populations, habitat, and other nesting waterbirds is well-documented in the primary scientific literature,” she said.

Kowalski also pointed to three papers discussing the issue.

One, a 2006 government report on cormorants in Ontario, notes that although anglers are concerned about the impact on fish, “Various studies have shown that cormorants can have an impact on fish abundance and production… however, there has been no evidence to suggest that cormorants have been responsible for the demise of any species in the Great Lakes-wide fish community.” The report also notes that climate change, overfishing and toxic contaminants are more significant threats for fish stocks.

The second paper, a 2004 report about cormorants at one provincial park in Ontario, recommends the birds be culled, but does not make mention of fish stocks. The third, a provincial discussion paper, says scientists are “currently working to determine if cormorants are having a significant influence on fish populations,” but does not include any conclusions.

Tonelli said the impact on fish stocks isn’t a top concern for the OFAH, though the organization is concerned that studies haven’t been done on how cormorants could affect smaller inland lakes, which they have recently started to settle on.

“Fishers should celebrate the existence of large colonies of cormorants,” said Liz White, a board member with the Animal Alliance of Canada who has campaigned against the cormorant hunt.

“It’s an indication that the fish populations in the area that they’re nesting in are abundant and healthy.”

Conservation authorities in the Kawarthas and Nipissing, which the government singled out in its announcement of the hunt as having cormorant problems, said they hadn’t worked on the issue.

Nipissing First Nation Chief Scott McLeod, who has more than 25 years of fishery experience, told Canada’s National Observer in an interview that cormorants haven’t had an impact on the nation’s fishery. He also says the hunt seems wasteful ⁠— cormorants aren’t edible.

“Everybody knows that cormorants are not a delicacy by any means,” he said. They’re “like eating a fish-duck,” he added. “It’s just not palatable.”

Though McLeod said he’s not anti-hunting, he also said he questions the science behind it.

“It’s not like I’m a renegade for the protection of cormorants… I don’t think any amount of hunting will affect them that much,” McLeod said. “I was not raised to go and kill things for nothing, and that just seems like what it is to me… I don’t know what purpose that serves, killing a bunch of birds.”

When asked what evidence the government was relying on when pointing to cormorant problems in the Kawarthas and on Lake Nipissing, Kowalski said the ministry heard “concerns from property owners, hunters and anglers, and commercial fishers.”

“We’re taking steps to help them deal with any local issues,” she said.

The Georgian Bay Association, which represents 3,000 families living along the northeastern arm of Lake Huron, said it isn’t troubled about the impact of cormorants on the ecosystem.

“We’re not really concerned about cormorant colonies, to be honest… there’s not a huge number,” said the association’s executive director Rupert Kindersley.

“We don’t believe it’s justifiable to hunt cormorants just because they make a mess of trees when they nest.”

Andrea Chreston, a project manager for the Toronto and Region Conservation Authority (TRCA) who works on managing cormorants at Tommy Thompson Park along the city’s shoreline, said rising numbers of cormorants there haven’t noticeably harmed fish populations.

“Based on our monitoring data... the cormorants have not had an impact on the fish population along the Toronto waterfront,” she said.

At Tommy Thompson Park in Toronto, cormorants are managed non-lethally. Park staff encourage them to nest on the ground, rather than in healthy trees. Photo courtesy Gail Fraser

Is there a better way to control cormorants?

Cormorants do have an impact on their ecosystem — that much is clear. And even if they are a native species, that impact can sometimes throw off the balance.

In addition to the possibility of fish stocks decreasing on smaller inland lakes, Tonelli said cormorants can also destroy habitat for other species. Their guano can kill trees and other vegetation, which can take many years to grow back after cormorants leave the area.

Governments have culled cormorants in the past at Ontario's Presqu'ile Provincial Park, and at Point Pelee. Fraser said if a cull must be done, it should be targeted.

“Using hunting as a way to control the population…. you have no control over it,” she said, adding that enforcing bag limits is difficult.

“Conservation officers would enforce rules and regulations as they normally do during any hunting or fishing season,” Kowalski countered.

At Tommy Thompson in Toronto, the conservation authority decided to use non-lethal methods to control cormorants. Staff realized the need to manage the birds in 2007 after they began to cause serious damage to the park’s tree canopy, Chreston said. The TRCA worked with scientists and the public to come up with a plan to encourage cormorants to nest on the ground, rather than in undamaged trees.

The most aggressive technique they use involves knocking down cormorant nests using long poles, Chreston said. “This is labour intensive, but it’s quite successful.”

The result? The park’s cormorant population has grown, but damage to the tree canopy doesn't appear to be increasing.

McLeod said he worries that humans think they know better than nature, an approach that can have unforeseen consequences.

“We end up time and time again doing things we shouldn’t have. I don’t think that this is any different, really,” he said.

“There are a lot of pigeons around, are they going to open a season on those? I don’t know what they’re thinking.”

Why is it any more acceptable to kill cormorants for no good reason than to kill giraffes, lions, or any other wild creature?
In addition, in lakes Simcoe and Couchiching, cormorants are reported to be controlling the population of the invasive round goby, which is a threat to native fish species.