Percids in the Canadian Waters of Lake Huron

1977 ◽  
Vol 34 (10) ◽  
pp. 1839-1848 ◽  
Author(s):  
G. R. Spangler ◽  
N. R. Payne ◽  
G. K. Winterton
Keyword(s):  
Population Biology ◽  
Yellow Perch ◽  
Perca Flavescens ◽  
Lake Huron ◽  
Past Century ◽  
Commercial Fishing ◽  
Commercial Catch ◽  
The Past ◽  
The North ◽  
Class Strength

Percids have never dominated the commercial catch from Canadian waters of Lake Huron but coincident with declining salmonid production, they contributed about 17% of the commercial landings from 1940 to 1975. Walleye (Stizostedion vitreum vitreum) production declined gradually over the past century whereas yellow perch (Perca flavescens) production increased irregularly since 1910.Walleye occur in relatively discrete stocks associated with rivers, inlets, and estuaries in the North Channel and Georgian Bay whereas southern Lake Huron stocks are seasonal residents of the southeastern rim of the main basin. Yellow perch are ubiquitous throughout the littoral waters of the lake. Growth rates of walleye are similar to those for more southerly populations in the Great Lakes and year-class strength is highly variable. Angling and commercial fishing contribute significantly to mortality rates in exploited stocks but deteriorating environmental conditions are probably more important to the persistence of walleye stocks in Lake Huron. At least one stock is presently threatened by industrial acidification of the watershed. Key words: Percidae, Lake Huron, production, population biology, Stizostedion, Perca

Population Dynamics of Walleye (Stizostedion vitreum vitreum) and Yellow Perch (Perca flavescens) in Lake St. Clair, Especially During 1970–76

1977 ◽  
Vol 34 (10) ◽  
pp. 1869-1877 ◽  
Author(s):  
D. A. Johnston
Keyword(s):  
Population Dynamics ◽  
Yellow Perch ◽  
Drainage Basin ◽  
Age Distribution ◽  
Perca Flavescens ◽  
Past Century ◽  
Commercial Fishing ◽  
Stizostedion Vitreum ◽  
High Concentrations ◽  
The 1960S

The fish community in Lake St. Clair has remained fairly stable over the past century despite extensive shoreline modifications, a tenfold increase in population in the drainage area, and exploitation from commercial and recreational fisheries. The lake is productive because of its shallowness and fertile drainage basin. The flushing action of clean water from Lake Huron has restrained deterioration of habitat from euthrophication in most areas.Annual commercial fishery landings of walleye (Stizostedion vitreum vitreum) in the 1960s were five times greater than in the previous 50 yr. The larger catches were due, in part, to increased effort, but also reflect a real increase in the walleye population. In contrast, the sauger (S. canadense) declined in abundance through the 1950s and disappeared from commercial landings in the early 1960s. As commercial fishing in Ontario waters of Lake St. Clair was banned in 1970 due to the discovery of high concentrations of mercury in fishes, information on the percid populations was restricted to that obtained from index fishing. Between 1970 and 1976, in association with weak year-classes, the mean age of walleye increased from 2.9 to 5.8 yr. Direct correlations between year-class strength and environmental factors were not evident from the available data. Fishing pressure was reduced considerably after 1970 and is not considered to be an important factor in the low recruitment. The yellow perch (Perca flavescens) population showed no evidence of a change in age distribution during the 1970–76 period. The reasons for the reduction in walleye recruitment after 1970 are not clear, but it is possible that the succession of strong year-classes in the 1960s was exceptional and that the recruitment in the 1970s is closer to the normal condition for walleyes in Lake St. Clair. Key words: Percidae, Lake St. Clair percids, Stizostedion, Perca, population dynamics, exploitation, community ecology

Walleye (Stizostedion vitreum vitreum) and Yellow Perch (Perca flavescens) Populations and Fisheries of the Red Lakes, Minnesota, 1930–75

1977 ◽  
Vol 34 (10) ◽  
pp. 1774-1783 ◽  
Author(s):  
Lloyd L. Smith Jr.
Keyword(s):  
Growth Rate ◽  
Yellow Perch ◽  
Climatic Factors ◽  
Perca Flavescens ◽  
Growing Season ◽  
Commercial Fishery ◽  
Class Strength ◽  
Parent Stock ◽  
Catch Statistics

In an investigation of the commercial fishery of Red Lakes, Minnesota, for the 46-yr period 1930–75, catch statistics were analyzed, and the dynamics of the perch and walleye populations were examined. Mean annual yields of walleye for two statistical periods, 1930–53 and 1954–75, were 309,900 and 245,100 kg, respectively for walleyes, and 96,400 and 109,500 kg for perch. Annual abundance (CPE based on average catches per day per 5-net units of gill nets) varied from 3.8 to 64.6 kg for walleye, and from 2.5 to 34.4 kg for perch. Causes of fluctuations in harvestable stock were directly related to strength of year-classes and to growth rate during the season of capture. Year-class strength was not related to the abundance of parent stock or of potential predators. The respective strengths of year-classes of perch and walleye in the same year were positively correlated (r = 0.859, P < 0.01), and are directly related to climatic factors. Growth rate of walleye in different calendar years varied from +30.7 to −42.2% of mean growth, and that of perch from +13.4 to −8.6% (1941–56). Growing season began in mid-June and was almost over by September 1. Walleye yield could be enhanced by starting harvest July 1 instead of early June. Perch yield could be improved by harvesting small perch. Key words: Percidae, Perca, population dynamics, Stizostedion, long-term yield

Famous teachers and educators of the first half of the XX century about the problems of the North Caucasian muslim education.

2021 ◽  
Vol 13 (2) ◽  
pp. 208-222
Author(s):  
Nadezhda O. Bleich ◽  
Keyword(s):  
Educational Process ◽  
Point Of View ◽  
Practical Significance ◽  
Past Century ◽  
North Caucasus ◽  
Caucasus Region ◽  
The Past ◽  
The North ◽  
New Type ◽  
Historical Heritage

The article is devoted to the consideration of the worldview positions of famous educators of the past century regarding the state of school education among Muslims of the North Caucasus region. It is proved that the enlighteners advocated the creation of a new type of national non-class school and the construction of the didactic foundations of the educational process in it. The novelty of the work is that, based on the analysis of the views of the advanced intelligentsia of the region, aimed at understanding the current socio-cultural situation, an attempt was made to scientifically understand the problems and prospects for the development of the Muslim educational system of the past from the point of view of the modern scientific paradigm. The practical significance of the publication lies in expanding the understanding of the system of Mohammedan education in the context of its historical heritage, which will help to comprehend modern problems associated with the reform of general and vocational education in the national Muslim republics.

The Thermal Regime of South Bay, Manitoulin Island

1967 ◽  
Vol 24 (1) ◽  
pp. 101-125 ◽  
Author(s):  
A. M. McCombie
Keyword(s):  
Thermal Regime ◽  
Thermal Stratification ◽  
Yellow Perch ◽  
Lake Trout ◽  
Smallmouth Bass ◽  
Lake Huron ◽  
Vertical Temperature ◽  
Class Strength ◽  
Influence Of Temperature On ◽  
History Of

The thermal regime of South Bay is described from records collected from 1953 to 1962 with thermometers, thermographs, and bathythermographs, the last being cast at 11 stations along the bay and one in Lake Huron. Warming begins in April and thermal stratification is established in June. Shallow areas warm more rapidly than deep in the spring and cool more quickly in autumn. The boundary between the epilimnion and the thermocline becomes sharper as summer advances but the transition from thermocline to hypolimnion remains gradual. The average seasonal trend of surface temperatures is a sine function with a maximum of 66 F in mid August and a minimum of 34 F in late March, though values outside this range occur frequently. At 180 ft the maximum of 47 F is attained in November. At the lake and outermost bay stations there is a temperature slump in June and July which may be due to an upwelling in the lake. Evidence of an exchange of water between the lake and bay is seen in vertical temperature sections and water movements Variations in epilimnial temperatures are correlated with those of the air temperature, but variations in epilimnial and hypolimnial temperatures appear to be unrelated. Finally, literature describing the influence of temperature on the year class strength of smallmouth bass, the distribution of lake trout, the growth of yellow perch, and the life history of Pontoporeia in South Bay is reviewed.

scholarly journals DPRK'S nuclear program

2020 ◽  
Vol 6 (Extra-A) ◽  
pp. 15-22
Author(s):  
Liailia Aidarovna Gainullina ◽  
Rustem Ravilevich Muhametzyanov ◽  
Bulat Aidarovich Gainullin ◽  
Nadiia Almazovna Galiautdinova
Keyword(s):  
Korean Peninsula ◽  
Northeast Asia ◽  
Republic Of Korea ◽  
Past Century ◽  
Nuclear Program ◽  
Korean People ◽  
Existing Problems ◽  
The Past ◽  
The North ◽  
Bilateral Relations

Historically, in the eyes of the Korean people, Japan is an antagonistic state that has brought them many troubles in the past century. Relations between Japan and the Democratic People’s Republic of Korea (DPRK) are fundamental in terms of security in the Northeast Asia (NEA) region, since the decision on the DPRK nuclear missile program and on the denuclearization of the Korean Peninsula is one of the pillars of achieving that very security throughout the region. The period, we consider in this study, from 1996 to 2006, is of significant importance, since a thorough analysis of the events of those years is important for understanding the root of existing problems in bilateral relations between Japan and North Korea. The present analysis on the behavioral lines in the solution of the North Korean nuclear missile program may contribute to the choice the best way to normalize relations between the two countries.    

scholarly journals Late Holocene temperature variability in Tasmania inferred from borehole temperature data

2017 ◽  
Vol 13 (6) ◽  
pp. 559-572 ◽  
Author(s):  
Asadusjjaman Suman ◽  
Fiona Dyer ◽  
Duanne White
Keyword(s):  
East Coast ◽  
Past Century ◽  
Borehole Data ◽  
Depth Profiles ◽  
The Past ◽  
North East ◽  
The North ◽  
Borehole Temperature ◽  
Temperature Depth

Abstract. Thirty-six borehole temperature–depth profiles were analysed to reconstruct the ground surface temperature history (GSTH) of eastern Tasmania for the past 5 centuries. We used the singular value decomposition method to invert borehole temperatures to produce temperature histories. The quality of borehole data was classified as high or low based on model misfit. The quality of the borehole data was not dependent on topography or land use. Analysis reveals that three to five high-quality borehole temperature–depth profiles were adequate to reconstruct robust paleotemperature records from any area. Average GSTH reconstructed from Tasmanian boreholes shows temperature increases about 1.2 ± 0.2 °C during the past 5 centuries. Reconstructed temperatures were consistent with meteorological records and other proxy records from Tasmania during their period of overlap. Temperature changes were greatest around the north-east coast and decreased towards the centre of Tasmania. The extension of the East Australian Current (EAC) further south and its strengthening around the north-east coast of Tasmania over the past century was considered a prime driver of warmer temperatures observed in north-east Tasmania.

Folk, Faith and Fatherland: Defining the Polish Nation in 1883

2000 ◽  
Vol 28 (3) ◽  
pp. 397-416 ◽  
Author(s):  
Patrice M. Dabrowski
Keyword(s):  
September 11 ◽  
Past Century ◽  
Hundredth Anniversary ◽  
The Past ◽  
The North ◽  
North Wall

On the north wall of Cracow's Church of the Annunciation (better known as the Carmelite Church at Piaski) hangs a long-ignored inscription. A simple stone tablet unprotected from the elements, its words have faded over the past century. One must strain to make out its cryptic message: “On September 11, 1883, Polish villagers gathered in Cracow solemnly celebrated the two hundredth anniversary of the relief of Vienna by John Sobieski, in remembrance of which this stone has been funded.”

Effects of recreational and commercial fishing on blue sharks (Prionace glauca) in Atlantic Canada, with inferences on the North Atlantic population

2006 ◽  
Vol 63 (3) ◽  
pp. 670-682 ◽  
Author(s):  
Steven E Campana ◽  
Linda Marks ◽  
Warren Joyce ◽  
Nancy E Kohler
Keyword(s):  
North Atlantic ◽  
Commercial Fishing ◽  
Single Population ◽  
Commercial Catch ◽  
Blue Shark ◽  
Prionace Glauca ◽  
The North ◽  
The Face ◽  
The North Atlantic ◽  
Population Mortality

The nominal catch of blue sharks (Prionace glauca) reported for the Canadian Atlantic grossly underestimates the annual catch mortality of about 1000 tonnes (t), making blue sharks the most frequently caught large shark in Canadian waters. Although blue sharks accounted for 99% of all sharks landed at recreational shark fishing tournaments, tournament catches accounted for only 3% of total fishing mortality. Standardized catch rate indices suggested a decline in blue shark abundance of about 5%–6%·year–1 since 1995. An increased mortality rate in recent years was suggested by a decline in the median size of blue sharks in the commercial catch. Two independent calculations suggest that North Atlantic catches exceeded 100 000 t, with catch mortalities ranging between 26 000 and 37 000 t. Because tagging studies indicated that blue sharks are highly migratory with a single population in the North Atlantic, the Canadian contribution to overall population mortality accounts for only 2% of the total. The fact that blue shark populations are relatively productive and resilient may help explain their persistence in the face of high international catch mortality and a decline in relative abundance.

The Great Migration in Context: The Chicago Experience, 1916–1918

2018 ◽  
Author(s):  
Christopher R. Reed
Keyword(s):  
Black Business ◽  
First World War ◽  
Past Century ◽  
Great Migration ◽  
World War ◽  
Wall Street ◽  
The Past ◽  
The North ◽  
The First World War ◽  
First World

The unanticipated and massive migration of half a million African Americans between 1916 and 1918 from the racially oppressive South to the welcoming North surprised the nation. Directly resulting from the advent of the First World War, the movement of these able-bodied workers provided essential labor to maintain wartime production that sustained the Allied war effort. One-tenth of the people who surged north headed to and remained in Chicago, where their presence challenged the status quo in the areas of employment, external race relations, internal race arrangements, politics, housing, and recreation. Once in the Windy City, this migrant-influenced labor pool expanded with the addition of resident blacks to form the city’s first African American industrial proletariat. Wages for both men and women increased compared to what they had been earning in the South, and local businesses were ready and willing to accommodate these new consumers. A small black business sector became viable and was able to support two banks, and by the mid-1920s, there were multiple stores along Chicago’s State Street forming a virtual “Black Wall Street.” An extant political submachine within Republic Party ranks also increased its power and influence in repeated electoral contests. Importantly, upon scrutiny, the purported social conflict between the Old Settler element and the newcomers was shown to be overblown and inconsequential to black progress. Recent revisionist scholarship over the past two decades has served to minimize the first phase of northward movement and has positioned it within the context of a half-century phenomenon under the labels of the “Second Great Migration” and the “Great Black Migration.” No matter what the designation, the voluntary movement of five to six million blacks from what had been their traditional home to the uncertainty of the North and West between the First World War and the Vietnam conflict stands as both a condemnation of regional oppression of the human spirit and aspirations of millions, and a demonstration of group courage in taking on new challenges in new settings. Although Chicago would prove to be “no crystal stair,” it was on many occasions a land of hope and promise for migrants throughout the past century.

Dependence of Total Annual Growth in Yellow Perch on Temperature

1966 ◽  
Vol 23 (1) ◽  
pp. 15-20 ◽  
Author(s):  
Daniel W. Coble
Keyword(s):  
Water Temperature ◽  
Yellow Perch ◽  
Perca Flavescens ◽  
Lake Huron ◽  
Annual Growth ◽  
Published Data ◽  
Red Lake ◽  
Air Temperatures

Total yearly growth of female yellow perch, Perca flavescens (Mitchill), in South Bay, Lake Huron, estimated by the distance along the lateral radius from last annulus to scale edge, showed a marked relationship to mean water temperature at a depth of 20 ft. When published data on growth of perch in Lower Red Lake, Minnesota, were compared with mean air temperatures for the period June through September at Redlake, no such relationship could be demonstrated. The reasons for the different results obtained in these and in other studies could not be determined.

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