Cormorants: So … What Do Real Scientists Say?

in Canadian

Double-breasted cormorant
(Painting by Barry Kent MacKay)

For the past 200 years there have been numerous studies of double-crested and other species of cormorants, both in North American and abroad, a large number of them designed to examine the “impact” cormorants have on various fish species. In response to FEIS, the American Ornithologists Union (AOU) struck a panel of ornithologists, not exclusive of wildlife management interests but decidedly academic, to review the U.S. Fish and Wildlife Service’s management plan of 2003. They did a massive literature review and stated:
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“In conclusion we find that (a) there is no good evidence presented in the FEIS that cormorants cause significant fisheries problems except in aquaculture and hatchery sites; (b) the solutions proposed, primarily increased take [lethal culling], would likely be ineffective at aquaculture and hatchery sites yet potentially destructive to continental cormorant populations; (c) how `success’ of a control program would be defined is unclear; and (d) there is no monitoring program in place or proposed that could evaluate success, or detect effects on continental cormorant populations. Consequently, it appears that what the USFWS plans to do constitutes persecution of a bird species rather than a solution to the real problems of declining fisheries and depredation of aquaculture and hatchery sites.”

This is no different from what other scientists, or CDI, has been saying, and the frustrating thing is it does not matter. The cormorant is the perfect foil, and focusing on it precludes the need to address real problems with the environment, including the endless introduction of non-native species with potential to harm the environment.

The likelihood is that the carnage against cormorants will continue, although inroads are being made.

Recently the Quebec government produced a handout that contained much of the usual anti-cormorant rhetoric with vague references to “reports” that cormorants drive away herons, and yet it states, “… most of the time, cormorants adapt their diet to the quantity and diversity of available prey without endangering fish species. Given that the natural mortality of the cormorant’s prey is already very high, it is hard to attribute the decline in fish numbers solely to the presence of cormorants. In Lake Saint-Pierre, for example, some have attributed part of the decrease in yellow perch stocks to cormorants. However, fishing success rates had already started to decline a few years before a colony of cormorants arrived on the lake. Cormorants are also abundant in Lake Saint-François, where yellow perch population rose 70 percent between 1996 and 2004 while nesting cormorants grew from a few individuals to nearly 800 breeding pairs.”

Quebec even suggests, as CDI has long advocated, encouraging ecotourism to cormorant breeding colonies. They are fascinating sights, indeed, to those truly interested in, and not fighting against, the natural world.

The Metro Toronto and Region Conservation Authority has declared parts of the East Toronto Headland, where cormorants and other colonial nesting birds occur in significant numbers, to be cormorant protection zones.

The true story about cormorants and fish is complex. Many people have neither the inclination nor even the ability to assimilate such complexity. Cormorants eat fish and for them that is the beginning and the end of the story.

It will change; facts have a way of floating to the top of myth. The world really is round. But in the meantime, the slaughter continues.

Introduction: Why Cormorants Can’t Kill All Fish

Wildlife Management North and South of the Border

Energy Transference, Basic Physics and the Technology Prosthesis

Back in the Real World

Cormorants: Food Chains and Basic Ecological Principles

The Alewife, Alien Salmon and Trout, and the Double-Crested Cormorant

The Round Goby

The Difference Between Science and Management

The Agricultural Subsidy

The Missing Predator Argument

Limiting Factors

Semi-Science and Wildlife Management

NEXT » Footnotes

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Cormorants: Footnotes