Successful Introduction of Mysis relicta Lovén into Kootenay Lake, British Columbia

1964 ◽  
Vol 21 (5) ◽  
pp. 1325-1327 ◽  
Author(s):  
R. A. H. Sparrow ◽  
P. A. Larkin ◽  
R. A. Rutherglen

not available

1970 ◽  
Vol 27 (7) ◽  
pp. 1239-1250 ◽  
Author(s):  
E. R. Zyblut

Macrozooplankton distribution and abundance as well as limnological conditions were compared during 1949 and 1964 in Kootenay Lake, a large oligotrophic lake in southeastern British Columbia. The standing crop of macrozooplankton increased two- to threefold over 15 years. Changes in physical–chemical limnological conditions, such as a decrease in depth of light penetration, and increases in pH, specific conductivity, dissolved nutrients, and phosphates also occurred, indicating an increase in productivity.The most noticeable change in macrozooplankton was a shift in cladoceran species composition in the north arm of the lake, formerly dominated by Daphnia but now by Diaphanosoma. Size-selective predation, differences in food availability, and competition for food with Diaphanosoma and Mysis relicta are suggested to be responsible for changes in the spatial distribution of Daphnia since 1949.Examination of changes in midsummer zooplankton abundance between successive years (1964–66) indicated that total zooplankton was least abundant in 1964. Differences in abundance during this period were small when compared with those between 1949 and 1964.


1990 ◽  
Vol 47 (3) ◽  
pp. 486-491 ◽  
Author(s):  
N. T. Johnston

A comparison of the growth of vertically-migrating kokanee (Oncorhynchus nerka) fry and nonmigrating fry confined to the epilimnion in thermally-stratified Kootenay Lake, British Columbia rejected the bioenergetic efficiency hypothesis for the adaptive significance of vertical migration. Growth rates were higher for nonmigrating fry than for vertically-migrating fry. Geometric mean wet weights in early October were 2.88 g for non-migrating fry and 1.40 g for vertically-migrating fry of the same stock. The geometric mean weight of fry of a second stock rearing in the isothermal West Arm, in which behavioural thermoregulation by vertical migration was not possible, was 8.54 g in early October.


2000 ◽  
Author(s):  
J M Journeay ◽  
S P Williams ◽  
J O Wheeler

1983 ◽  
Vol 40 (1) ◽  
pp. 78-81 ◽  
Author(s):  
R. D. Evans ◽  
D. C. Lasenby

The potentially important mechanism of biological mobilization of lead from lake sediments was investigated. Lead concentrations of the crustacean Mysis relicta from Kootenay Lake, determined using atomic absorption spectrophotometry, were compared to published lead sediment concentrations from the same sites. There is a strong correlation between sediment-lead concentration and Mysis-lead concentration. This correlation may indicate that Mysis can accumulate lead from the sediment and return it to the open water.Key words: Mysis relicta, lead, heavy metal contamination, contaminated sediments.


1992 ◽  
Vol 70 (3) ◽  
pp. 470-475 ◽  
Author(s):  
Christoph Steeger ◽  
Hans Esselink ◽  
Ronald C. Ydenberg

We compared the general breeding and feeding ecology of ospreys (Pandion haliaetus) in the Creston and Nelson areas of southeastern British Columbia. In the Creston Valley, ospreys nested atop tall trees surrounding a shallow and productive warm-water marsh. Prey species taken by male ospreys included black bullhead (Ictalurus melas), pumpkinseed (Lepomis gibbosus), and yellow perch (Perca flavescens). In contrast, near Nelson, ospreys nested on man-made structures along the narrow West Arm of Kootenay Lake. Osprey prey species in the Nelson area included longnose sucker (Catostomus catostomus), largescale sucker (Catostomus macrocheilus), and mountain whitefish (Prosopium williamsoni). Prey captured at Nelson were larger and contained significantly more energy than at Creston Valley, and hunting from a perch was used for 26% of all captures. All Creston Valley prey were caught by flight hunting. The strike success of foraging ospreys at Nelson was significantly higher than at Creston, and the net yield of flight hunting was 3 times higher. In spite of these differences, the breeding performance of ospreys in the two areas was very similar. Average clutch size was 2.8, brood size at hatching was 2.0, and the average pair fledged 1.4 young. The nest failure rate did not differ between the two areas. Most clutches were initiated in early May, with Nelson-area ospreys laying, on average, 4–7 days later. Egg volumes were smaller at Nelson (66.6 vs. 69.1 cm3). However, the rate at which nestlings gained mass was significantly greater at Nelson. We discuss reasons why the breeding performance varies so little in spite of the great differences in feeding regime.


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