The Alberta Bull Trout

Where are they, where did they go and why are they protected?

The native species of Alberta’s trout species are like the fresh water sharks of the ocean, they hit hard, fight hard and are willing to take almost anything you put in front of them. They were once common place in Alberta but the introduced species of Rainbow, Brown and Eastern Brook trout have almost driven them to the brink of extinction here and abroad. The Bull Trout had a wide area of rivers and streams to call home in Alberta, but over harvesting and other competition from introduced species has left them in jeopardy forever. Many years ago these beautiful species of trout were caught and thrown away, sometimes on the banks to rot in favor of the more sought after trophy fish like browns and rainbow trout species.

Previously, populations of bull trout were abundant in the headwaters of all major drainage systems on the eastern slopes of the Rocky Mountains. Creel counts and anecdotal records dating back to the late 1800’s show that the species flourished throughout the upper regions of the South Saskatchewan River drainage and north as far as the Peace River. More recently, the number of bull trout has declined substantially. Sadly, they were nearly eradicated from Kananaskis streams and have been completely extirpated both from much of the Red Deer River drainage as well as substantial portions of the Alberta southwestern streams. Records show evidence that the normal range for bull trout extended well out onto the prairies. There are records of bull trout angling in the Oldman River downstream as far as Lethbridge, in the vicinity of Carseland on the Bow River, in the badlands of the Red Deer River and in the Edmonton area of the North Saskatchewan River. None of these areas are currently inhabited by bull trout and present estimates indicate that the species occupies only thirty percent of its historical range (Donald G. Groft).

A few years ago I was fishing the Highwood River near the Stampede Ranch; I cast my spinner into one of many pools that swirl throughout this wild river. I hook into a 14 inch rainbow and the trout goes crazy flopping and jumping trying to escape the spinner. Then out of nowhere a voracious bull trout comes up and slams the fish I have hooked, ripping it away from the grasp of my lure. As hearty fighters and aggressive feeders, bulls don’t hesitate to snack on other par or fry. According to the Alberta Conservation Association website, “Protection depends on designation. Alberta Sustainable Resource Development is considering the modification of logging operations upstream of an area with the highest redd densities until the tributary is classified as a Class A water body. This is the highest habitat sensitivity designation possible under Alberta’s Water Act Code of Practice for Watercourse Crossings. The legislation would see any proposed activities affecting this critical stream follow a process that involves site-specific review and approval by Alberta Environment, Department of Fisheries and Oceans and Alberta Fish and Wildlife. Special restrictions associated with building watercourse crossings over Class A streams also prevent any further harvest in the tributary. With the implementation of these conservation measures, we will not only help protect essential spawning habitat, but also support viable populations of bull trout throughout the upper Oldman River watershed. And if we give that to them, we’ll be lucky to have future generations of anglers continue to tell the tale of the time that pesky bull trout snapped up their prize”

You can still effectively fish for this native Alberta trout species in some rivers and lakes in both northwest Alberta and in the southern reaches. Rivers like the Highwood, Castle, Crowsnest, Livingstone, and the Oldman River where the Alberta bull trout record was caught from. There are also fair numbers of bulls in both the Upper Kananaskis Lake and the Lower Kananaskis Lake where many anglers catch good sized bulls in both open water and hard water conditions. Personally I have caught many large bulls from the lower lake in both spring and the fall months. Bull trout are willing to take a variety of lures and spoons that mimic baitfish and will also hit large spinners and plugs in lakes and rivers. Once you hook one, it is proper to get the fish in quickly and leave it in the water while removing the hook from its mouth. If a picture is taken, lift the fish up from both the tail and support the underbelly of the fish at the same time. Take a few quick pictures and then revive the fish properly moving the trout back and forth gently to get water moving back into its gills. Many fish can and do die from improper handling and or keeping the fish out of the water too long. The better care we as anglers take with all fish, the more trout we will keep alive in our rivers and lakes here in Alberta.

In regards to the decline of this protected fish, I refer to a thesis paper written by Donald G. Groft for his Master of Science degree at the University of Lethbridge. I have left his citations intact here. “A variety of reasons for this decline have been proposed including: (1) loss of habitat, (2) over fishing and (3) competition with introduced species. Fraley et al. (1989) described the effect of timber harvest and road building on the quality of stream beds used for spawning. They found that even moderate streambed silting greatly reduced fry production. Successful bull trout spawning depends on stringent requirements for gravel covered stream beds. The long incubation and development phase for bull trout embryos makes them particularly vulnerable to increases in fine sediments or changes in water quality (Fraley and Shepard, 1989).

Loss of habitat also occurs with the introduction of physical barriers in the streams such as dams and weirs. The Dickson and St Mary’s River dams have introduced impassable barriers which effectively eliminate downstream portions of bull trout migratory routes (Roberts, 1991). The completion of the Oldman River Dam in 1991 blocked the last remaining access to prairie streams by bull trout (Nelson and Paetz, 1992). Fish that do manage to get downstream cannot return to their spawning areas and ultimately die without the ability to maintain viable downstream populations. Over fishing is considered a major contributor to the decline of bull trout populations (Boag, 1987; Roberts, 1987). The fish are easy and exciting to catch because of their broad diets and aggressive feeding habits (Roberts, 1993). The situation is exacerbated by slow rates of maturation. Typically, it takes five to seven years for bull trout to reach spawning age (Roberts, 1987) by which time many are caught and removed from the population.

Bull trout compete with other fish on a variety of levels. Boag investigated food competition between bull trout and rainbow trout (Oncorhynchus mykiss). Though bull trout are more piscivorous than rainbow; they assume similar diets in the upper reaches of some streams. Of interest was the large number of fish eggs found in the stomachs of rainbow trout, raising the possibility that introduced species may contribute to the decline of bull trout through predation on eggs. Donald and Alger (1993) reported that lake trout (Salvelinus namaycush) caused the displacement of bull trout from lakes located in regions where the two species have overlapping niches. In one lake, introduction of lake trout decimated an indigenous population of bull trout over a thirty year span.

Competition with brook trout also may contribute to declines in bull trout populations. Brook trout have been introduced into every major drainage of the Canadian Central Rockies ecosystems region (Mayhood, 1995). Hybridization between bull trout and brook trout was documented in several studies (Kitano et al., 1994; Markle, 1992). There is little evidence that such hybridization is solely responsible for the decline of bull trout populations but it may be a contributing factor in regions where bull trout numbers are already low. For example, Roberts (1993) suggested that hybridization most likely occurs if male bull trout are scarce and many male brook trout are in the vicinity of bull trout females. Thus, bull trout x brook trout hybridization may be more the result rather than the cause of a decline in bull trout (Roberts, 1987). In any case, such crosses perpetuate loss of bull trout because potential pure-line progeny are lost and the hybrids are usually sterile (Kitano et al., 1994).

The decline in Alberta bull trout populations parallel a similar situation in the eastern slopes region of Montana. In 1989, bull trout were added to the American Fisheries Society updated list of fishes that are endangered, threatened, or of special concern. They were categorized as fish of “special concern” due to the threatened destruction of habitat and various factors affecting their existence including hybridization, introduction of exotic species, predation and competition. Application in the United States for protection of the species under the Endangered Species Act has been made.

The status of bull trout in Canada has been under review by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) since 1988 (Campbell, 1988) and the species was recently described as “vulnerable” (Campbell, 1994), indicating official concern over declining populations. In Alberta, a comprehensive plan geared towards the management and recovery of bull trout populations was introduced in 1994 (Berry, 1994). The plan focused on conservation tactics and recommended zero catch limits in the recreational fishery. In addition, future studies were proposed including a suggestion that genetic studies be performed to investigate hybridization with brook trout. Concurrently, an alliance of organizations including sport-fishing groups, conservation groups, university academics and regional governments formed the Bull Trout Task Force (BTTF), through which priorities were set for future research related to Alberta bull trout (Bull Trout Task Force, 1995). The need for genetic studies of Alberta bull trout populations was recognized by this group although such studies were designated as low priority.

Currently, no genetic studies of Alberta bull trout have been completed. Consequently, management strategies were designed without knowledge of genetic structure or the extent of genetic variation among bull trout populations. In Montana, genetic studies revealed little intrapopulation variation but significant interpopulation variation. The importance of these differences should not be underestimated. The presence of genetic differentiation among populations may indicate significant levels of local adaptation (Carvalho and Hauser, 1994). Consequently, management strategies should consider the local effects of such practices as habitat alteration, stocking and introduction of other species. In this context, understanding the extent of genetic variation within a species is important in the formulation of a rational management scheme (Ferguson, 1990). If the genetic integrity of locally adapted populations is to be preserved, they must be characterized relative to geographical references so that informed management decisions can be made. Increasingly, management strategies are based on ecosystem preservation rather than species preservation (Stanford and Ward, 1992). The loss of local bull trout populations may affect the existence of many other species in the ecosystem (Mayhood, 1995). Preservation of entire communities requires long-term commitments to habitat protection. Monitoring these communities requires baseline status information for accurate assessment of future changes in fish populations (Williams et al., 1989). Genetic studies provide a sensitive measure of baseline status and they facilitate the detection of changes in local gene pools. One American study suggested that a bull trout stocking program would provide a promising management option for the recreational fishery (Fraley et al., 1989). This proposal was met with severe criticism from several researchers. Leary et al. (1993) suggested that stocking may lead to loss of local adaptations and does not remove the original causes of population decline, such as habitat destruction. Though the essence of hatchery programs is to introduce fish for the rehabilitation of natural populations, the practice disregards the 6 concept that species are divided into genetically distinct localized units which are adapted to their particular environment (Ferguson, 1990). Such local adaptations may include the timing and extent of migration, temperature preferences, growth rates, foraging strategies and life history characteristics. Introduced fish have the potential to disrupt the genetics of these local populations, possibly resulting in local extirpation and a reduction in regional diversity. The presence of diverse locally adapted populations contributes to greater regional stability because multiple variant populations are less likely to go extinct simultaneously (Rieman and Mclntyre, 1996). Conservation efforts should encourage the existence of local variant populations, but a stocking program likely would homogenize the gene pool promoting the opposite effect.

In summary, the decline in Alberta bull trout populations has been well documented and efforts to reverse this decline are ongoing. Current management practices cannot consider potential genetic differences among Alberta bull trout because no previous genetic studies exist. The implementation of genetic research on bull trout should greatly enhance future management efforts through the identification of specific localized gene pools and the establishment of baseline data for monitoring future changes in the genetics of these populations”.

With efforts from the Alberta Fish and Wildlife department, and improved angler awareness on the proper identification of bull trout, it is my hope that this beautiful resident fish will make a strong comeback here in Alberta. As anglers and stewards of the resource, we should make a conscious effort to increase the survival of the bull trout species locally and promote river and stream recovery plans for our beloved native trout. Continuing to promote catch and release only fishing, plus helping the species to recover and thrive in Alberta should be in the forefront of local anglers agendas. If we all do our part to stop poaching, habitat destruction and improper handling techniques, maybe just maybe our children will fish for this species for many years ahead. Remember, “NO BLACK, PUT IT BACK” which refers to, no black spots on the dorsal fin, it is a bull trout and must be put back!