Copyright © 2008 Don H. Meredith, All Rights Reserved.
It is one of the most popular lakes in Alberta. It is less than an hour’s drive from Edmonton with people coming on weekends and holidays to partake of its beaches, cottages, trails, birding, boating and fishing. For decades it supported the largest commercial and sport fishery in Alberta. Today, the Wabamun Lake fishery is a shadow of its former self.
I have lived near the lake for many years, and it has been one of my favorite places to fish year around. To me, what is happening to the Wabamun fishery illustrates what is happening to our resources in general throughout the province as our human population grows and applies increasing pressures on our limited resources.
Before we can evaluate the current fishery we need to know its history. Fortunately, Wabamun Lake is the most studied lake in the province. According to the 2004 report “Lake Wabamun: A review of Scientific Studies and Environmental Impacts” (written for Alberta Environment by a panel of scientists chaired by David Schindler of the University of Alberta), Lake Wabamun might have been heavily fished as far back as the mid-1800s, when it supplied fish to the people of Edmonton. As the province and city have grown so has interest in the lake’s fisheries.
In terms of game fish, Wabamun has had viable native populations of lake whitefish, northern pike, yellow perch and walleye over the years. However, the walleye population was never large and it was eventually fished out in the early 20th century. Attempts by Alberta Fish and Wildlife to restock walleye have failed, probably a result of the increased fishing pressure and the habitat changes the Wabamun power plant introduced to the lake (starting in the 1950s) through the plant’s warm effluent water.
By far, the most important fishery in the lake has been its lake whitefish population. The commercial fishery was one of Alberta’s largest in terms of number of nets set and tonnes of fish harvested. In some years, upwards of 200 km of gill nets were set harvesting more than 200 tonnes of lake whitefish (as high as 500 tonnes one year in the late 1950s).
Since commercial fishing records were first kept in the early 1890s, the lake whitefish population at Wabamun has gone through 10 to 20 year cycles of peaks and valleys. However, in the last two decades, the population was not showing its usual recovery and was in a steady decline. The problem was failure of recruitment of young fish into the adult (breeding) population, most likely the result of increased fishing pressure by both commercial and recreational fishers. As a result, the commercial fishery was closed in 2003, along with a reduction in the number of whitefish taken by recreational anglers to conserve the declining fish stock.
Over the decades, Wabamun was known for producing large pike. However, in the 1990s anglers reported loss of quantity and quality of the pike fishery on this and other lakes in the province. Subsequent studies classified the pike population as vulnerable in Lake Wabamun and many other lakes. As a result, a management strategy was introduced in 1999 that placed restrictions on fishing for pike. For Wabamun, a minimum size limit of 63 cm in total length and a three-fish-per-day possession limit were implemented. However, illegal harvest of undersize fish continued; and until the commercial season was cancelled, commercial nets continued to take large pike incidental to the whitefish they were targeting. The pike continued to decline in numbers.
I have caught yellow perch in Wabamun over the years. In the 1970s and early ‘80s, we would regularly see perch up to 10 inches in length; but these larger, eating-size fish were few and far between, becoming increasingly scarce in the following years. Today, the perch in the lake fail to reach any significant size that would support a fishery of any sort. Apparently, this is typical of a eutrophic lake such as Wabamun.
Unfortunately, Wabamun now is known more for the train derailment that occurred on its north shore in August of 2005 than it is for its fine recreational opportunities. As a result of that derailment, about 712,000 litres of Bunker C fuel oil was spilled, of which 150,000 litres reached the lake water. Over the last two years, considerable work has been done to clean up the oil, mostly from the shoreline and vegetation. Fortunately, little of the oil actually sank into the lake itself. Much of it was blown by the wind across the lake to the southeast shoreline before it had a chance to weather and sink. Intensive clean up efforts have recovered most of this oil.
Also included in the spill were approximately 150,000 litres of pole-treating oil, a highly carcinogenic substance. Fortunately, only trace amounts of this oil reached the lake.
The train derailment was indeed a disaster, but after some initial missteps, industry, governments and concerned citizens came together to clean up the spill and mitigate the effects on the environment and the residents around the lake. After two years the lake looks very good and people are returning to it to recreate. However, some concerns still remain.
Effects of the Spill on the Fisheries
One of the many concerns about the oil spill is what will be its effect on the quality of the fisheries. An oil spill can affect fish in a variety of ways including smothering eggs and food; putting toxicants into the water, food and lake sediment; and destroying habitat. Alberta Sustainable Resource Development, Environment Canada, and CN and its consultants immediately started work to monitor the fish populations and their habitats.
Fish habitat was most adversely affected by the clean-up activities where vegetation was removed to facilitate recovery of the oil in the water and along the shore. These areas should recover without further disturbance. Early studies indicated the presence of some polycyclic-aromatic-hydrocarbons (PAHs) in the tissue of fish in the lake. PAHs indicate fuel oil contamination. However, the quantities were low in August of 2005, and a second study in October of that year found no traces of PAHs in fish tissue. Thus, it looks like the adult fish populations were minimally affected by the oil spill. However, there is some concern about how the spill may be affecting spawning. Trays of white fish eggs were placed at several sites around the lake to monitor the effect of the water on the development of eggs and fry. Early results indicate some deformities in fry above normal levels but complete results are not yet in.
Immediately following the oil spill the number of anglers on the lake dropped dramatically. Capital Health issued a warning about eating potentially contaminated fish and boat access was restricted to prevent stirring up the oil. Boat access was eventually restored but Capital Health has maintained its warning. As a result, lake whitefish numbers have been increasing since the spill. However, biologists are concerned that these increases could be masking longer term effects of residual contaminants on the population. In 2007, despite the continued Capital Health warning, the number of anglers on the lake started to increase. Fish and Wildlife is concerned that an increasing number of anglers taking fish could negatively impact the recovery of both whitefish and pike.
Even before the oil spill, the whitefish and pike populations were in danger of collapse. Therefore, Alberta Fish and Wildlife has proposed for the 2008-09 season that fishing on Wabamun Lake for all species of fish be restricted to catch-and-release only to allow the populations to recover to self-sustaining levels. If we want to see the fisheries at least approach their historic production, it is the least we should be doing.
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