Wednesday, May 11, 2005

Much more on the cormorants

Last week, I posted an article fromThe Toronto Star about a culling (mass killing) of cormorants on the north shores of Lake Ontario. That article quoted a man from the Ontario Federation of Anglers and Hunters (OFAH) named Robery Pye. I wrote Mr. Pye an email, and the exchange is as follows:

Andrew wrote:

Mr. Pye, I read an article today in the Toronto Star regarding the culling of 5,500 double-crested cormorants in Presqu'ile Provincial Park. You can find that article on their website:

In the article, you mentioned that this sort of culling is necessary for "proper wildlife management." If you wouldn't mind, I would appreciate an explanation of how this culling is necessary for "proper wildlife management."

I await your response,
Andrew Woods

Robert wrote:


In the case of over-population of cormorants at Presqui'le, I have referred to culling as "proper wildlife management" -- but only as the last option wildlife managers have to restore balance to that ecosystem.

If the government had acted sooner on developing a seasonal cormorant management program, as the O.F.A.H. has been advocating for years, a cull of5,500 cormorants may not have been required; and miles of shoreline habitat could have been saved.

However, now that we have a cormorant crisis of over450,000 in the Great Lakes Basin alone (250-times historic population records), a cormorant cull is biologically necessary. Plenty of deliberation and good science supports the cull.

In this case, a cull is within the best interest of proper wildlife management.

Hope this information helps.

Andrew wrote:

Robert, thanks for the information. I have a couple more questions, if you wouldn't mind:

1) do we have an understanding of why or how the cormorant population has boomed?

2) what would be the consequences if the cull were not carried through?

Robert wrote:

Hi Andrew:

1.) A ban of DDT has provided better reproduction of cormorant eggs. Also,invading species such as zebra mussels have increased water clarity, making it easy for these birds to hunt for food in our great lakes and inland waters.

"By the early 1970s, DDT and similar pesticides virtually wiped out the cormorant population. A ban on DDT, a decline in phosphorous and persistent toxic chemicals and the presence of non-native Alewives, Round Gobies and Rainbow Smelt contributed to the cormorant’s recovery." -- as reported in the Trentonian.

2.) As the population increases (with no bust in population in sight) these birds will continue to damage shoreline habitat, and decimate our fisheries. In Ontario, the net effect is over 42 million pounds of fish consumed by cormorants each year. The cormorant eats its weight in fish a day -- in other words, it takes about 3 avg. size perch to feed its daily appetite.

If you take a drive along Lake Ontario shorelines, particularly near Brighton, you'll discover the skeletons of mature shoreline trees that may never recover. The damage is caused by cormorant droppings that are highly acidic.There is no other predator for the cormorant.

The OFAH is not advocating cormorant eradication, rather cormorant control. Culling is a necessary evil because the government didn't act quickly enough when the science community, the OFAH and other environmentalists warned about the consequences of cormorant over-population. Culling is not a long term solution... its merely an immediate step to designed to save special places like Presquile and help restore balance to our fisheries as well as safeguard bird and fish habitat. Culls need to be followed through with cormorant management programs (I'm sure you can appreciate the role wildlife managers and conservationists have played in helping to manage a host of other successful species, particularly waterfowl, deer, coyotes, bears, etc) An independent scientific review committee has already recommended cormorant management for Presquile. Yes, we could wait and hope for a bust in cormorant populations. Unfortunately, while we do this, Presquile and other unique ecosystems will continue to be damaged or eliminated permanently.

Hope this information helps.

Andrew wrote:

Robert, I very much appreciate you answering me. I have a few final questions, if you still have the time and you don't mind:

1) Do you have any idea of the historical cormorant population - before the use of DDT began?

2) Are zebra mussels natural to Ontario? If so, what caused their population boom? If not, how did they get here?

3) Have anglers had a hard time catching fish these past few years? And do they think it's a result of the cormorant boom?

Robert wrote:


1.) Before the ban of DDT in the 1970's --- it's believed cormorants in Ontario saw their peak in abundance at about 50 to 100 nesting pairs (in the1950's) in the whole G. Lakes basin. That's a far cry from the thousands of cormorants that are now nesting along the shores of Brighton alone. In 1982, the MNR counted only one cormorant nest, but in 2002 they counted over 12,000.

2.) Zebra mussels are an invading species --- believed to have been carried over from Russia and dumped from the ballast tanks of ocean going ships into the St. Lawrence River. No other organization is doing as much to combat invading species than the OFAH. Invading species are wreaking havoc on Great Lakes food webs. Invading species are considered the second greatest threat to biodiversity -- next only to habitat loss.


3.) We know the massive amounts of bait fish and sport fish they take from our lakes -- over 42 million pounds in Ontario. However, there are many factors for anglers success rates --- or lack there of, including the arrival of invading species such as round goby, zebra mussels, rudd, spiny water flee, etc. Angler success rates are a complex puzzle of various issues, specific from year to year, region to region and lake to lake.

I'll stress again that the cormorant crisis is not a just a "fishing"issue -- it's an issue that anyone who enjoys and cares about our natural resources should be aware of.


Interesting. Robert was a good sport in answering all my questions.

Throughout history, species populations have fluctuated, and some species have even been eliminated.

However, never has a species been so active in affecting other species as has humans on just about everything else, and particularly in the last 300 years, give or take.

This could be the result of callous negligence and lack of foresight, as in the case of the zebra mussels that Robert Pye mentioned, or as a result of greed and sickening inhumanity, as in the cases of industrialized farming or the seal hunt.

While I applaud the intentions of groups like Mr Pye's, I disagree that a cull should ever be a) necessary or b) within the dominion of humans to carry out.

And the eternal skeptic in me questions the motives of the OFAH - if it weren't so hard to catch fish or if the trees weren't so unsightly, would the OFAH really care about the cormorant population? Would the OFAH even have gotten involved? I wonder about that.


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