Limnological survey of the Lake Louise area, Banff National Park. Part 2: the lakes.
A limnological survey of 31 lakes and ponds in the vicinity of Lake Louise, Banff National Park, was made. Data were gathered on the drainage basin features, morphometry, general attributes, water chemistry, phytoplankton, plankton primary productivity, zooplankton, macrophytes, shoreline fauna, benthic fauna and fish populations of the lakes. The data were presented in a "lake—by-lake" format for management reference purposes, and were used in a summary section to characterize the limnology of the study area. Two distinct groups of lakes were discerned in the Lake Louise area those on the floor of the Bow Valley (the "low lakes"), and those in the cirques and hanging valleys tributary to the Bow Valley (the "high lakes"). There were marked differences noted between the high and the low lakes with respect to their physical attributes, water chemistry and biological communities. The lakes within each group were similar physically, chemically and biologically, with few exceptions. Nearly all of the fish populations of lakes in the study area were introduced. Probably fewer than half of them are capable of maintaining themselves without supplementary stocking, because natural recruitment is low or absent. Scarcity of suitable spawning habitat is believed to be the most important cause of poor natural recruitment in many of the lakes. Growth of brook and cutthroat trout, the two most important sport fishery species in lakes of the study area, is slow. In the case of many of the brook trout and all of the cutthroat trout populations, fish growth is as slow as, or slower than, the slowest growth rates recorded in the literature. Nevertheless, such low growth rates are probably typical of those of brook and cutthroat trout in lakes in the southern Canadian Rocky Mountains. Similarly, individuals of/these two species in the study area reached ages rarely recorded in the literature, but these ages are probably not particularly unusual for the two species in lakes of the southern Canadian Rocky Mountains. Trout in lakes of the study area ate mainly Chironomidae, Trichoptera and Amphipoda. Use of the amphipod Gammarus lacustris as food in some trout populations was suggested as part of the reason for the relatively higher growth rates of fish in those populations. In most respects, the lakes of the study area do not differ greatly from those in the southern Canadian Rocky Mountain region in general. The low lakes, however, had some noteworthy inhabitants. A rare species of ostracode, Notodromas monacha, was found along the shoreline of Kingfisher Pond. The water strider Gerris incognitus, found in Little Herbert Lake and McNair Pond, may be a new but not unexpected record for Alberta. The planktonic copepod Acanthodiaptomus denticomis, found in most of the low lakes, appears in the Rocky Mountain Parks to be restricted to small lakes in the Bow Valley in Banff Park. However, it is known elsewhere in western Canada from several waters in central British Columbia, central Saskatchewan, and from a few other small lakes in the Bow Valley outside of Banff Park.