So far, workers have killed cormorants at five of the 13 sites, while resorting to harassing the birds at the rest.
On the Les Cheneaux Islands, workers have visited the local cormorant colony multiple times this year on lethal control missions, Frontjes said.
It will take time to shrink a colony that has rebounded since the former federal control program ended, he said, but “I’m thankful that we’re able to stop the growth.”
Does killing birds save fish?
Not everyone agrees.
In a position statement opposing the order, the Michigan Audubon Society noted that other pressures on the Great Lakes, from invasive mussels to habitat loss and pollution, pose far bigger threats to Great Lakes fish.
By killing cormorants, the group said, government officials are “encouraging the persecution of a visually-obvious target, when the reasons for dwindling sportfish populations are complex and lack a silver bullet.”
Other seabirds also eat fish, noted Ludwig, the Ontario-based scientist. But cormorants, with their black plumage and prehistoric appearance, bear the brunt of anglers’ ire.
He chalks it up to a sharply disputed theory of “cultural bias against any animal that’s black,” combined with the cormorant’s communal nesting habits: Their densely-packed colonies make them a highly-visible target.
Ludwig believes the killing program will needlessly harm a native bird species that may already be in decline. A federal program that once kept close track of cormorant nesting sites ended in 2008, he said. As a result, species managers lack a clear picture of how Great Lakes cormorant populations are faring today.
The fish and wildlife service has vowed to develop a protocol to resume monitoring within a year.
Ludwig said his surveys of selected cormorant colonies in the Great Lakes indicates the birds are struggling to find food and protect their nests from eagles that have started eating cormorant chicks as a replacement for the disappearing fish.
“The entire structure of the ecosystem shifted,” Ludwig said, and the culprit is invasive mussels, not hungry cormorants.
Scientific studies have drawn mixed conclusions about whether the birds can drive down sportfish numbers in the Great Lakes, though there is clearer evidence of their impact in smaller inland lakes.
On the big lakes, fish and wildlife managers say the birds’ nesting behavior makes them a localized threat.
Cormorant colonies can number as large as thousands of nesting pairs. One study found that as cormorant numbers rose on the Les Cheneaux Islands, the local perch fishery collapsed.
With all those birds confined in a small area, Frontjes said, “they can do a ton of damage in a very short amount of time,” picking off perch by the thousands as the fish gather in the islands’ shallow bays to spawn.
Nobody is proposing eliminating the birds entirely, Frontjes said, “but you can't have them totally decimating other species, either.”
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After federal rule change, Michigan resumes killing cormorants to save fish - Bridge Michigan
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