Cormorants

by Captain Tony R. Degasperis

Lately much attention has been focused on the so-called "exotics" in Lake Huron and Georgian Bay and the threat they pose to the fishery. In an attempt to account for an apparent lack of bait fish, the MNR and the Lake Huron Management Unit, commercial fishermen and "expert" biologists (whose research is funded, in part, by these same people), have turned to blaming everything from salmon to zebra mussels. Yet, alongside commercial fishing, the greatest threat to re-establishing and maintaining a healthy and productive fishery is the double-crested cormorant. Get rid of these fish-eating predators and fish populations will return to normal levels.

Double-crested cormorants are not indigenous to the Great Lakes Basin. They began colonizing the area in the 1900's, with their numbers peaking in the 1940's. The number of cormorants was reduced to almost zero in the 1970's because of high levels of DDT in the water. The banning of DDT, combined with changes to wintering areas and the availability of food resources, has allowed the population of cormorants to explode. Scientists estimate that the population of cormorants is now in excess of 500,000 birds, over 250 times historic population levels.

Cormorants can live up to 12 years. Each adult cormorant consumes a minimum of one pound of fish per day. They can swallow fish up to 16 inches long, indiscriminate of the type (bait/sport fish). The alewife is the primary source of food and is the staple of the cormorant's diet. Other prey include yellow perch, stickleback, sculpin, rainbow smelt, suckers, as well as crustaceans, insects, and amphibians. Over one season the birds will consume 42 million pounds of fresh water fish, amounting to 75% of fish stocks. Clearly, omitting this voracious eater from the bait fish equation is completely asinine.

Results from a five-year study conducted by the OMNR have proven what anglers have been saying for years: cormorants are having a devastating effect on the fishery and the entire ecosystem of Lake Huron. Cormorants consume approximately 30% of the annual fish biomass of the lake and harvest 3 times the biomass of documented commercial fishery harvests. Two years ago, to merely maintain fish populations, a 60% reduction in the number of nesting cormorants was recommended by Ministry experts.

The Canadian Wildlife Service performed a nest count of cormorants on Chantry Island in May, 2005. There were over 1400 active nests. This is only one of many small islands throughout Lake Huron and Georgian Bay that has been overrun by these birds. An over-abundance of cormorants destroys shoreline vegetation, affects water quality and bio-diversity, and decimates the forage fish base. The consequences are so severe that, once cormorants have established themselves, the recovery of the entire aquatic ecosystem is in question, including the survival and growth of game fish species.

The seasonal migration of cormorants brings them back into our region by early May. By this time, most of the smelt have already spawned, undisturbed, along shorelines and in streams. Unfortunately, the cormorant's return coincides perfectly with when the alewives spawn. Huge flocks of cormorants will gorge on adult alewives before they've had a chance to spawn, thereby greatly reducing the overall number of the next generation of these bait fish. Continue this pattern season after season and the result will be exactly what we see happening in Georgian Bay and Lake Huron -a drastic cut in the number of alewife.

Since initial salmon stocking in Georgian Bay began, the population of this much sought after sport fish is at an all-time low. The salmon caught today are generally smaller than they once were, and consistently have empty bellies. (This is not due to a quick metabolism.) Their main source of food, like the cormorant, is the alewife. (It should be noted that even experienced anglers misinterpret the stomach contents of their catch. Stickleback are often misidentified as small perch.) Despite the claims of some biologists, the salmon is not an "all-consuming" predator. If that were the case, the salmon bellies would be as full as those of other sport fish. (For example, lake trout bellies are consistently full. The lake trout (which is over-stocked in Georgian Bay) eats mainly smelt. However, it is not unusual to find alewife, whitefish, sculpin, suckers, young salmon, or even other lake trout.) Most assuredly, the suggestion that salmon are to blame for the lack of bait fish is not only erroneous, but also grossly misleading.

Currently Lake Simcoe, Lake Nippissing, Lake Manitou, and many other inland lakes, are suffering from a sharp decline in their perch populations. Once plentiful, the number of perch has all but bottomed-out. None of these lakes have salmon, but anglers will tell you that each of these lakes has cormorants, and only two (Lake Simcoe and Chesley Lake) have zebra mussels.

The presence of zebra mussels in the Great Lakes has provided the MNR with another faulty reason for problems in the local fishery. Zebra mussels are tiny mollusks that prefer to live in shallow, warmer water where they survive by filtering plankton. In sufficient numbers, zebra mussels could negatively effect the aquatic food chain. However, there are not enough zebra mussels in Lake Huron and Georgian Bay to blame for a subsequent lack of bait fish. Between June and October, Georgian Bay and Lake Huron are teaming with plankton, more than enough to provide an adequate food supply for the tiniest of consumers, ensuring a stable and intact food chain.

One highly confusing reason offered by the MNR for a lack of bait fish in our waters is the weather. It is their contention that the extremely cold winter of 2003/04 made it impossible for bait fish, like the alewife, to survive. Yet, in the next breath, the MNR will tell you that the mild winters of the last couple of years have allowed the deer and wild turkey populations to thrive. Huh? In actual fact, according to Environment Canada, the winter of 1993/94 recorded the coldest temperatures over the past 20 years. Monthly averages for December, January and February were colder than in 2003/04, and both January and February 1994 saw extreme temperatures sink to -30 degrees or colder.

The same people repeatedly told anglers that the reason there didn't seem to be as many salmon around was that the fish were "late" in returning to the rivers to spawn and water levels were low. One year we were told the water temperatures were too cold, the next year they told us it was too warm. According to the MNR, the salmon have been later and later for the last few years...they refuse to acknowledge that the salmon weren't merely "late", there are actually fewer and fewer fish. They need to acknowledge that the fall salmon run starts according to a biological clock: if the fish are here, they will show up. And let us not forget the fin-clipping fiasco of recent years when the MNR recommended clipping the fins on newly hatched fish, only for them to become easy prey for every predator in the water (a practice that continues today on rainbow and lake trout). Very rarely are clipped salmon or rainbow caught by anglers. Mother Nature gave fish fins for a reason. A little common sense in this matter would go a long way. Also, if the MNR is really concerned about the recent decline in bait fish populations, then why have they allowed the practice of dip-netting spawning smelt to continue?

So-called "experts" are happy to report that the populations of whitefish (the target of commercial nets) are healthy. They would have us believe that commercial fishing isn't having a negative effect on the number of whitefish in Lake Huron and Georgian Bay but, in the future, to expect a "natural" decline in the over-all population. In reality, commercial fishing nets have destroyed the lake trout population (the natural predator of whitefish), thereby cutting the pressure on the whitefish. The "natural decline" of whitefish in the future will actually be the result of over-fishing by the commercial fishery. Other "experts" have told us about the recent invasion of round gobi into Georgian Bay. Gobi have been part of the food web in our waters for a number of years...just ask anyone who actually fishes here. To point the finger at these "exotics" as the cause of problems in our fishery, while ignoring the cormorant, is hardly credible. Both Lake Ontario and Lake Michigan have more "exotics" than Georgian Bay and Lake Huron, and Lake Ontario and Lake Michigan still have salmon with full bellies. What the two lakes don't have is as great a cormorant population. (Cormorants prefer to colonize in less populated areas. Manitoulin Island is the worst case of over population by these black devils.)

The MNR admits that one of the underlying problems with the fishery is the inadequate legislation and regulations for protecting fish communities and fish habitat. Yet, because of federal regulations, hunting cormorants is not permitted. Even in the face of the results of their own studies and "expert's" recommendations, the OMNR has opted for a very weak approach to the entire situation. Oiling a few eggs or conducting more research is not going to eliminate the pressure being put on the fishery by cormorants; study after study continue to reach the same conclusions. Surprisingly, the Ministry still claims "insufficient knowledge" about the state of the resource. There is no doubt that attempts by the Ministry to focus attention elsewhere (e.g. blaming salmon for the lack of bait fish) is nothing more than a politically correct move on their part. The Federal Fisheries and Oceans Department has no difficulty recognizing and acknowledging the sea lamprey as a predator that threatens fish stocks, yet refuses to act upon the obvious detrimental results of an out-of-control cormorant population. Giving in to the rhetoric of very vocal animal rights advocates is no way for the Ministry to perform their stewardship responsibility with respect to management of the fishery.

A short time ago, Lake Huron and Georgian Bay were visited by a research vessel gathering information about bait fish populations. The fisheries biologist onboard, Jeff Schaeffer, was eager to provide a tour of the vessel and discuss its impressive scanning equipment. Unfortunately, he was much less eager to offer explanations or provide proof for conclusions he was already drawing about the fishery. This trip, admittedly, was his first visit to Lake Huron and Georgian Bay. He also stated that "there are a lot of politics involved" in what he was doing. Why would there be "politics" involved in pure data gathering?

The biologist was definitely not a fisherman. He was unaware of other studies that had been carried out previously concerning the state of the fishery, and shockingly ignorant of basic species knowledge. For example, he did not know what a cisco is, and he was surprised to learn that gobies are well-established in the area. Any interest he had in cormorants was directed at what effect their feces was having on vegetation, not on what the birds consumed. When questioned about the conclusions he was drawing (which he had reached before completing the research) he was vague and eager to change the subject. He was anxious to attack the salmon, yet had no logical, factual information to backup his claims. He finished the conversation by saying that he thought cormorants only consumed 15% of the bait fish and that salmon were eating the rest. And this is the person who is heading the bait fish research and, presumably, the person the public is going to look to for answers. How very, very unfortunate.

Left alone, the population of cormorants will eventually balance out with the available food supply. Unfortunately, it will be at the expense of the sport fishery, other bird species, and the environment. Is the government prepared to compensate businesses, including the tourism industry, for lost revenue because of the Ministry's mishandling of the fishery? We cannot allow the disastrous impact of cormorants to go unchecked. We have to be the top predator. In order to have a truly healthy and productive fishery in Ontario, the government must bring the cormorant population under control. Hiding an unwillingness to take action behind a "need for more studies" is not going to accomplish a thing.

Proper management of the fishery will ensure balance of the resource:

  • Get rid of the cormorants!
  • Rehabilitate all water courses so that bait fish and sport fish can access them easily and reproduce productively. The Mill Dam in Owen Sound was the first fish ladder in Ontario. It is unproductive and neglected by the MNR. As well, vast expanses of the tributaries entering our major rivers are not being managed effectively. Water temperature is extremely important to fish and shaded areas are vital. The spawning channels below Inglis Falls on the Sydenham River have not been maintained for a number of years. The water courses in our area (if they can be accessed easily by the fish) are highly productive, contrary to what the Lake Huron Management Unit says.
  • Establish and enforce stiffer controls on commercial fishing operations. For the government to state that a major cause of the reduction in the numbers of fish is over-harvesting, and then turn a blind eye, is negligence. Over-fishing of 1030% above quota is on record with the MNR.
  • Stop all fish stocking programs.

Data quoted in this article is available from the Ontario Ministry of Natural Resources, the Wisconsin and Michigan Departments of Natural Resources, the Ontario Federation of Anglers and Hunters, various publications by the Bruce Peninsula Sportsmen's Association, the Great Lakes Sport Fishing Council, the Lake Huron Fishing Club, and Environment Canada.