Population Dynamics of Lake Whitefish (Coregonus clupeaformis) During and After the Fertilization of Lake 226, the Experimental Lakes Area

1987 ◽  
Vol 44 (S1) ◽  
pp. s55-s63 ◽  
Author(s):  
K. H. Mills ◽  
S. M. Chalanchuk
Keyword(s):  
Population Dynamics ◽  
The Other ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Experimental Lakes Area ◽  
Northwestern Ontario

Responses of an unexploited population of lake whitefish (Coregonus clupeaformis) to the fertilization of Lake 226 in the Experimental Lakes Area, northwestern Ontario, are described for the fifth through eighth years of fertilization (1977–80) and for three years after fertilization was terminated (1981–83). A vinyl curtain separated Lake 226 into two basins. One basin (L226NE) received additions of phosphorus, nitrogen, and carbon; the other (L226SW) received nitrogen and carbon. Lake whitefish in L226NE were faster growing, had higher condition (k), were more numerous, had higher survival from age 0 to age 1, had greater biomass, and had greater production than L226SW whitefish from 1977 to 1980. Some of these effects continued in 1981 and 1982 after fertilization was terminated, but only biomass differences remained by 1983.

Responses of Lake Whitefish (Coregonus clupeaformis) to Fertilization of Lake 226, the Experimental Lakes Area

1985 ◽  
Vol 42 (1) ◽  
pp. 129-138 ◽  
Author(s):  
K. H. Mills
Keyword(s):  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Experimental Lakes Area ◽  
Annual Survival ◽  
Northwestern Ontario

The responses of an unexploited population of lake whitefish (Coregonus clupeaformis) to fertilization of Lake 226 (L226), the Experimental Lakes Area, northwestern Ontario, were measured for 4 yr (1973–77). A vinyl sea curtain separated the lake into a northeast (NE) basin, which received P, N, and C additions, and a southwest (SW) basin, which received only N and C additions. Lake whitefish in the NE basin grew faster, had higher coefficients of condition, and had greater recruitment and production than those in the SW basin during the 2nd through 4th yr of fertilization. No differences between basins were detected in annual survival for fish [Formula: see text], but survival of age 0 fish was greater in the NE basin. Whitefish production in L226NE averaged twice that in L226SW from the 2nd to the 4th yr of fertilization, though significant variations occurred between years in both the NE and SW populations.

Migration and development of swim-bladder nematodes, Cystidicola spp. (Habronematoidea), in their definitive hosts

1980 ◽  
Vol 58 (11) ◽  
pp. 1997-2005 ◽  
Author(s):  
Geoff A. Black ◽  
Murray W. Lankester
Keyword(s):  
Rainbow Trout ◽  
Lake Trout ◽  
Distinct Species ◽  
Salmo Gairdneri ◽  
Swim Bladder ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Northwestern Ontario ◽  
Third Stage ◽  
Migration And Development

Third-stage larvae of Cystidicola cristivomeri White, 1941, and C. farionis Fischer, 1798, migrated directly via the pneumatic duct to the swim bladder of lake trout, Salvelinus namaycush, and rainbow trout, Salmo gairdneri, respectively. Larvae reached the swim bladder as early as 16 h after fish were infected using a stomach tube. At 4–10 °C, mature male and female C. cristivomeri and C. farionis were first recovered 67 and 210 days, and 112 and 235 days, respectively, after infection. Cystidicola cristivomeri is probably long-lived; there was no evidence that any died in lake trout infected for up to 600 days.Large numbers of third-stage cystidicolid larvae accumulated without maturing in the swim bladder of naturally infected lake whitefish, Coregonus clupeaformis, from Lake Nipigon, northwestern Ontario. When given to rainbow trout, these larvae matured and the adult nematodes were identical to C. farionis. These results suggest that the swim-bladder nematode that matures in lake whitefish is a distinct species.

Effects of Gamma Irradiation on Salmonella spp. in Smoked Lake Whitefish (Coregonus clupeaformis)

1971 ◽  
Vol 28 (5) ◽  
pp. 643-646 ◽  
Author(s):  
K. Ostovar ◽  
R. R. Pereira ◽  
R. A. Gallop
Keyword(s):  
Gamma Irradiation ◽  
The Other ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Salmonella Spp

A dosage of 0.5 M rad was found sufficient to eliminate three species of Salmonella in smoked lake whitefish (Coregonus clupeaformis) regardless of the stage of processing at which steaks were inoculated with the bacteria. All three species survived smoking at temperatures up to 167 F. The dosages required for elimination of the bacteria when steaks were inoculated at various stages of processing were: before freezing at 0 F for 48 hr, 0.4 M rad for S. give, 0.3 for S. typhimurium, and 0.2 for S. java; before brining at 60 Salometer for 25 min, 0.4, 0.3, and 0.3; after smoking, 0.5, 0.4, and 0.35. Salmonella give was more resistant to heat than the other two species.

Life History, Morphology, and Electrophoretic Characteristics of Five Allopatric Stocks of Lake Whitefish (Coregonus clupeaformis) in the Great Lakes Region

1981 ◽  
Vol 38 (12) ◽  
pp. 1790-1807 ◽  
Author(s):  
P. E. Ihssen ◽  
D. O. Evans ◽  
W. J. Christie ◽  
J. A. Reckahn ◽  
R. L. DesJardine
Keyword(s):  
Genetic Distances ◽  
The Other ◽  
Body Measurements ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Electrophoretic Variation ◽  
Branching Patterns ◽  
Meristic Variation ◽  
Biochemical Variation ◽  
Pyloric Ceca

Ecological, morphological, and electrophoretic variation among five allopatric Ontario lake whitefish (Coregonus clupeaformis) stocks was studied. The stocks differ in terms of diet, growth rate, movement patterns, fecundity, and egg and larval size. Morphologically, the five stocks were also different for characters such as number of gill rakers, number of pyloric ceca, and in size, adjusted for fork length, of the tail, dorsal fin, and the eye. Discriminant functions, derived from body measurements and meristic counts, classified specimens accurately into their lakes of origin. Highly significant allele frequency differences were found at 6 of the 32 electrophoretic loci examined. Standard genetic distances, derived from electrophoretic allele frequency differences, corresponded roughly to the order in which these stocks became isolated following retreat of the last continental glaciation. The genetic distance of the Opeongo stock from the other stocks is about one order of magnitude larger than the genetic distances among the other stocks. The Opeongo stock is also somewhat unusual ecologically, having different egg size and fecundity characteristics compared with the other stocks and being a member of a sympatric dwarf/normal pair. Dendrograms, derived from the Mahanalobis distances for the meristic variation and the Nei genetic distances for the electrophoretic variation, showed similar branching patterns, but the branching patterns for the morphometric versus the biochemical variation were different. A significant part of the morphometric variation among the stocks was related to differences in growth rates of the stocks, most body measurements being negatively correlated with growth rate. The Mahanalobis distances for the meristic variation (including pyloric ceca counts) were correlated with the standard genetic distances from the electrophoretic data. The ecological, morphological, and biochemical variation among the stocks, in relation to local adaptation, is discussed.Key words: lake whitefish, stock concept, genotype, phenotype, ecology, morphology, meristics, multivariate analysis, electrophoresis, growth, diet, fecundity

scholarly journals The influence of two wildfires and biological control agents on the population dynamics of Melaleuca quinquenervia in a seasonally inundated wetland

2021 ◽  
Vol 14 (1) ◽  
pp. 3-8
Author(s):  
Philip W. Tipping ◽  
Melissa R. Martin ◽  
Jeremiah R. Foley ◽  
Ryan M. Pierce ◽  
Lyn A. Gettys
Keyword(s):  
Biological Control ◽  
Population Dynamics ◽  
Seedling Recruitment ◽  
Additional Treatment ◽  
Seed Rain ◽  
The Other ◽  
Melaleuca Quinquenervia ◽  
Biological Control Agents ◽  
Seedling Mortality ◽  
Sapling Growth

AbstractThe potential of Melaleuca quinquenervia (Cav.) S.T. Blake to reinvade cleared areas was evaluated over a 13-yr period that included two wildfires and the introduction of biological control agents. The first wildfire occurred in 1998 and was followed by a mean of 591.5 recruited seedlings m−2. Recruits from that fire were cleared 7 yr later in July 2005 for a second experiment to evaluate seedling recruitment into cleared areas. Seed rain, seedling recruitment and mortality, and sapling growth rates were measured in four plots located around individual large reproductive trees. A second natural wildfire in 2007 burned through those plots, leading to increases in seed rain followed by a pulse in recruitment of 21.04 seedlings m−2, 96.5% fewer than after the 1998 fire. Recruits in half of the plots around each tree were then treated with regular applications of an insecticide to restrict herbivory by biological control agents, while herbivory was not restricted in the other half. There was no difference in seedling mortality between treatments 1,083 d post-fire (2007) with 96.6% seedling mortality in the unrestricted herbivory treatment and 89.4% mortality in the restricted herbivory treatment. Recruits subjected to the restricted herbivory treatment grew taller than those in the unrestricted herbivory treatment, 101.3 cm versus 37.4 cm. Many of the recruits were attacked by the biological control agents, which slowed their growth. Although solitary M. quinquenervia trees retain some capacity to reinvade areas under specific circumstances, there was a downward trend in their overall invasiveness at this site, with progressively smaller recruitment cohorts due to biological control agents. Land managers should prioritize removing large reproductive trees over treating recently recruited populations, which can be left for many years for the biological control agents to suppress before any additional treatment would be needed.

Land water linkages: influences of riparian deforestation on lake thermocline depth and possible consequences for cold stenotherms

1997 ◽  
Vol 54 (6) ◽  
pp. 1299-1305 ◽  
Author(s):  
Robert France
Keyword(s):  
Thermal Stratification ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Thermocline Depth ◽  
Experimental Lakes Area ◽  
Northwestern Ontario ◽  
Riparian Trees ◽  
Tree Removal ◽  
Riparian Tree ◽  
Land Water

The purpose of the present study was to determine if riparian deforestation would expose lake surfaces to stronger winds and therefore bring about deepening of thermoclines and resulting habitat losses for cold stenotherms such as lake trout (Salvelinus namaycush). Removal of protective riparian trees through wind blowdown and two wildfires was found to triple the overwater windspeeds and produce thermocline deepening in two lakes at the Experimental Lakes Area. A survey of thermal stratification patterns in 63 northwestern Ontario lakes showed that lakes around which riparian trees had been removed a decade before through either clearcutting or by a wildfire were found to have thermocline depths over 2 m deeper per unit fetch length compared with lakes surrounded by mature forests. Riparian tree removal will therefore exacerbate hypolimnion habitat losses for cold stenotherms that have already been documented to be occurring as a result of lake acidification, eutrophication, and climate warming.

Spatial and temporal dynamics of lake whitefish (Coregonus clupeaformis) health indicators: Linking individual-based indicators to a management-relevant endpoint

2010 ◽  
Vol 36 ◽  
pp. 121-134 ◽  
Author(s):  
Tyler Wagner ◽  
Michael L. Jones ◽  
Mark P. Ebener ◽  
Michael T. Arts ◽  
Travis O. Brenden ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Health Indicators ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Spatial And Temporal Dynamics

Development of the embryonic heat shock response and the impact of repeated thermal stress in early stage lake whitefish ( Coregonus clupeaformis ) embryos

2017 ◽  
Vol 69 ◽  
pp. 294-301 ◽  
Author(s):  
Lindy M. Whitehouse ◽  
Chance S. McDougall ◽  
Daniel I. Stefanovic ◽  
Douglas R. Boreham ◽  
Christopher M. Somers ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Early Stage ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Shock Response ◽  
The Impact

Fecundity Comparisons for Various Stocks of Lake Whitefish, Coregonus clupeaformis

1975 ◽  
Vol 32 (3) ◽  
pp. 404-407 ◽  
Author(s):  
M. C. Healey ◽  
C. W. Nicol
Keyword(s):  
Northwest Territories ◽  
Lake Erie ◽  
Fork Length ◽  
Nonlinear Relationship ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Limited Data ◽  
Relative Fecundity ◽  
Great Slave Lake ◽  
The Relationship

We found no significant differences in slope or intercept for the regression of loge fecundity on loge fork length among samples of whitefish from four lakes near Yellowknife in the Northwest Territories. The equation describing the relationship between fecundity and fork length for these populations was:[Formula: see text]Five other populations for which length–fecundity relationships could be calculated had length exponents ranging from 3.20 to 4.38, suggesting a nonlinear relationship between weight and fecundity. Six of the nine populations as well as four others for which limited data were available all had similar relative fecundities. Fish from Buck Lake in Alberta and from Lake Erie had high relative fecundities while fish from Great Slave Lake had low relative fecundity.

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