Speckled trout population parameters, habitat conditions and management strategies in lakes in Nova Scotia, Canada

2016 ◽  
Vol 48 (2) ◽  
pp. 189
Author(s):  
Amy Ryan ◽  
John L. MacMillan
Keyword(s):  
Nova Scotia ◽  
Population Density ◽  
Yellow Perch ◽  
Management Strategies ◽  
Fork Length ◽  
Small Population ◽  
Population Parameters ◽  
Habitat Conditions ◽  
Trout Population ◽  
Density And Biomass

A principal components analysis was conducted on the results of published reports and data sets from technical papers that include speckled trout Salvelinus fontinalis population estimates from 14 Nova Scotia lakes. The purpose of this paper was to identify the factors that influenced trout density and biomass. Population parameters, including mean fork length (cm), population density (n/ha), and population biomass (kg/ha), relative to variation in lake size, acidity, and competitor species were assessed and compared among lakes. Populations with small mean length and slow growth displayed larger fish density and biomass suggesting density-dependence. Acidic conditions potentially impact spawning potential and reduced recruitment that resulted in small population density and larger trout. The number of other fish species present in the lakes was used as an index of competition and had the greatest impact on trout density and biomass in Nova Scotia lakes. Yellow perch seemed to have the most impact of all the competitor species. In five lakes that contained yellow perch the mean trout population biomass was 0.19 kg-ha-1 (0.2,SD) compared to 4.5 kg-ha-1 (0.26, SD) in eight lakes that did not contain perch species. Lentic habitat conditions can greatly influence the potential success of different fisheries management strategies.

scholarly journals GROWTH AND OVERPOPULATION OF YELLOW PERCH AND THE APPARENT EFFECT OF INCREASED COMPETITION ON BROOK TROUT IN LONG LAKE, HALIFAX COUNTY, NOVA SCOTIA

2012 ◽  
Vol 47 (1) ◽  
Author(s):  
Cathy L. Munro
Keyword(s):  
Nova Scotia ◽  
Brook Trout ◽  
Yellow Perch ◽  
Slow Growth ◽  
River System ◽  
Von Bertalanffy ◽  
Scale Analysis ◽  
Age At Maturity ◽  
Apparent Effect ◽  
Trout Population

A fish survey was conducted on Long Lake, Woodens River, Halifax County, Nova Scotia during May 2005. A total of 2711 yellow perch were captured over a twelve day period and were the most abundant fish. Fifty-eight yellow perch were sampled for length, weight, scales, and sex. Total length of yellow perch ranged from 81mm to 276 mm with a mean of 133mm. Ages determined from scale analysis ranged from 2 to 13 years but 95% were younger than 8 years of age. Age at maturity was 2 years. The Von Bertalanffy growth relationship for yellow perch described slow growth and suggested stunting which is consistent in crowded populations. Increased abundance of yellow perch and reduced abundance of brook trout has been reported by anglers in the Woodens River system and was evident from our catches. The apparent effect of increased, intraguild competition on the brook trout population is discussed.Keywords: yellow perch, brook trout, overpopulation, stunting, intraguild competition.

Organochlorine Residues in Brook Trout and Yellow Perch From New Brunswick and Nova Scotia (Canada) Lakes

1987 ◽  
Vol 22 (3) ◽  
pp. 352-364
Author(s):  
R. Peterson ◽  
S. Ray
Keyword(s):  
Nova Scotia ◽  
New Brunswick ◽  
Brook Trout ◽  
Yellow Perch ◽  
Intensive Agriculture ◽  
Fish Tissues ◽  
North Central ◽  
Ddt Metabolites ◽  
Headwater Lakes

Abstract Brook trout and yellow perch collected while surveying New Brunswick and Nova Scotia headwater lakes were analyzed for DDT metabolites, chlordane, hexacyclohexane isomers, hexachlorobenzene, toxaphene and PCB’s. Concentrations of DDT metabolites were much higher from fish taken from lakes in north-central N.B. (200-700 ng/g wet wt) than from fish taken elsewhere (<10 ng/g). Seventy to 90% of the DDT metabolites was DDE. Chlordane (3-13 ng/g) was analyzed in seven trout, six of them from central N.B. areas with intensive agriculture. Isomers of hexachlorocyclohexane were in highest concentration from north-central N.B. (10-20 ng/g), eastern N.S. (5-15 ng/g) and southern N.B. (5-20 ng/g). In most cases, alpha-hexachlorocyclohexane (lindane) was the isomer in highest concentration. Concentrations of hexachlorobenzene in fish tissues was highly variable with no obvious geographic bias. PCB’s were detected in very few fish, and no toxaphene was detected.

scholarly journals Population Density or Populations Size. Which Factor Determines Urban Traffic Congestion?

2021 ◽  
Vol 13 (8) ◽  
pp. 4280
Author(s):  
Yu Sang Chang ◽  
Sung Jun Jo ◽  
Yoo-Taek Lee ◽  
Yoonji Lee
Keyword(s):  
Population Density ◽  
Population Size ◽  
Traffic Congestion ◽  
Critical Role ◽  
Small Population ◽  
High Density ◽  
Urban Traffic ◽  
Contradictory Result ◽  
Low Density

A large number of articles have documented that as population density of cities increases, car use declines and public transit use rises. These articles had a significant impact of promoting high-density compact urban development to mitigate traffic congestion. Another approach followed by other researchers used the urban scaling model to indicate that traffic congestion increases as population size of cities increases, thus generating a possible contradictory result. Therefore, this study examines the role of both density and population size on traffic congestion in 164 global cities by the use of Stochastic Impacts by Regression on Population, Affluence and Technology model. We divide 164 cities into the two subgroups of 66 low density cities and 98 high density cities for analysis. The findings from the subgroups analysis indicated a clear-cut difference on the critical role of density in low-density cities and the exclusive role of population size in high-density cities. Furthermore, using threshold regression model, 164 cities are divided into the two regions of large and small population cities to determine population scale advantage of traffic congestion. Our findings highlight the importance of including analysis of subgroups based on density and/or population size in future studies of traffic congestion.

Stochastic models that predict trout population density or biomass on a mesohabitat scale

Hydrobiologia ◽  
1996 ◽  
Vol 337 (1-3) ◽  
pp. 1-9 ◽  
Author(s):  
Philippe Baran ◽  
Sovan Lek ◽  
Marc Delacoste ◽  
Alain Belaud
Keyword(s):  
Population Density ◽  
Stochastic Models ◽  
Trout Population

PREDATION BY INSECTS AND SPIDERS INHABITING COLONIAL WEBS OF HYPHANTRIA CUNEA

1972 ◽  
Vol 104 (8) ◽  
pp. 1197-1207 ◽  
Author(s):  
R. F. Morris
Keyword(s):  
Population Dynamics ◽  
Nova Scotia ◽  
North America ◽  
Population Density ◽  
New Brunswick ◽  
Numerical Response ◽  
Initial Number ◽  
Hyphantria Cunea ◽  
The North ◽  
The Mean

AbstractThe number of predators inhabiting nests of Hyphantria cunea Drury was recorded annually for 13 years in four areas in New Brunswick and two areas on the coast of Nova Scotia. The most common groups were the pentatomids and spiders, which sometimes reproduced within the nests, but the mean number per nest was low in relation to the number of H. cunea larvae in the colonies. The rate of predation on fifth-instar larvae was low. Small or timid predators appeared to prey largely on moribund larvae or small saprophagans during the principal defoliating instars of H. cunea.No relationship could be detected between the number of larvae reaching the fifth instar and the number of predators in the colony; nor could any functional or numerical response of the predators to either the initial number of larvae per colony or the population density of colonies be found. It is concluded that the influence of the nest-inhabiting predators is small and relatively stable, and may be treated as a constant in the development of models to explain the population dynamics of H. cunea.H. cunea is a pest in parts of Europe and Asia, where it has been accidentally introduced from North America. The introduction to other continents of the North American predator, Podisus maculiventiis (Say), is discussed briefly.

scholarly journals Aspects of the ecology of Penelope superciliaris temminck, 1815 (Aves: Cracidae) in the Araripe National Forest, Ceará, Brazil

2015 ◽  
Vol 75 (4 suppl 1) ◽  
pp. 126-135 ◽  
Author(s):  
T. N. Thel ◽  
P. H. R. Teixeira ◽  
R. M. Lyra-Neves ◽  
W. R. Telino-Júnior ◽  
J. M. R. Ferreira ◽  
...  
Keyword(s):  
Direct Observation ◽  
Feeding Ecology ◽  
Management Strategies ◽  
Natural Populations ◽  
Line Transect ◽  
National Forest ◽  
Population Parameters ◽  
Neotropical Forests ◽  
Frugivorous Birds ◽  
Fecal Samples

Abstract Guans are large frugivorous birds that inhabit Neotropical forests and play a fundamental role in seed dispersal and forest regeneration. Despite their ecological importance, the natural populations of these birds are increasingly threatened by deforestation and hunting pressure. The present study was conducted in the Araripe National Forest, Ceará (Brazil), with the objective of estimating population parameters (density and total population size) in the Rusty-margined Guan (Penelope superciliaris) and the White-browed Guan (Penelope jacucaca), as well as providing data on their feeding ecology, including seasonal variation and fruit morphology. The study was based on the monthly collection of data between November, 2011, and October, 2012. Population parameters were estimated using line transect surveys, while feeding ecology was studied by direct observation, and the collection of plant and fecal samples. The estimated population density of P. superciliaris was 19.17 individuals/km2 (CV=13.98%), with a mean of 0.13 sightings per 10 km walked. Penelope jacucaca was not encountered during the surveys. A total of 14 plant species were recorded in the diet of P. superciliaris, 12 by direct observation, and two from fecal samples. Fruit diameter varied from 6.3±1.35 mm (Miconia albicans) to 29.9±1.7 mm (Psidium sp.). Yellow was the most frequent fruit color (41.6%, n=5), with two species each (16.6%) providing black, green, and red fruits. Fleshy fruits of the baccate (50.0%, n=6) and drupe (33.3%, n=4) types were the most consumed. The data on population parameters and feeding ecology collected in the present study provide an important database for the development of effective management strategies by environmental agencies for the conservation of the populations of the two guan species.

scholarly journals Population Variability and Heat Bias Prediction in a Tropical Country, Nigeria, From 2006 to 2036

2018 ◽  
Vol 4 (1) ◽  
pp. 28-38
Author(s):  
Peace Nwaerema ◽  
David Edokpa
Keyword(s):  
Population Density ◽  
Management Strategies ◽  
Positive Association ◽  
Population Variability ◽  
Land Use Management ◽  
High Concentration ◽  
Tropical Country ◽  
Safe Place ◽  
National Population ◽  
Land Mass

This research explores population variability and heat bias prediction in a tropical country, Nigeria from 2006 to 2036. Data were generated from the projections of the National Population Commission (NPC) using the population mathematical model for heat bias data.  With national population growth rate of 2.67%, Nigeria recorded heat bias of 60C in 2016, 6.1oC in 2026 and 6.20C in 2036 as well as 0.10C decadal variation indicating that it has exceeded the 0.5-0.250C standard comfort threshold. The analytical results show that there is a positive association between population density and heat bias across the states of Nigeria with greater effects in states such as Lagos, Anambra, Imo, Abia, Akwa Ibom Ekiti, Rivers, Osun and Ebonyi due to the high concentration of people in their limited land mass. And more of the eastern states of Nigeria will have much effect of the heat bias due to their high population density. It shows that land mass does not have any association with heat bias and will likely be influenced by land modification and atmospheric characteristics. Heat wave could result to death of people; therefore, national planners should implement environmental, health and land-use management strategies with immediate action in order to make Nigeria a safe place to live.

scholarly journals Parietaria pensylvanicu Mühlenb. ex Willd. - potentialities of migration from park habitats to segetal communities

2013 ◽  
Vol 53 (1) ◽  
pp. 65-74
Author(s):  
Anna K. Sawilska ◽  
Józef Misiewicz
Keyword(s):  
North America ◽  
Life Strategy ◽  
Vegetable Crops ◽  
Habitat Conditions ◽  
Vegetation Season ◽  
Type Selection ◽  
Density And Biomass ◽  
Segetal Communities

Parietaria pensvlvanica Mühlenb ex. Willd is a species native to North America, whose occurrence in Poland was first reported in Bydgoszcz in 1991. Its biology and ecology has been researched since 1996. The present paper discusses measurements and phenological observations carried out on four selected populations during the vegetation season in 1997. The aim of the research was to determine potentialities of the migration of P. pensylvanica from park habitats to segetal communities, on the basis of a defined life strategy of the examined populations. The analysis focused on the dynamics of density and biomass as well as on the weight of 1000 nucules, against the habitat conditions. The findings demonstrated that the investigated species was characterised by a set of life strategy properties referred to as C-S-R or S-R, and was subject to the "r"-type selection. P. pensylvanica has become an integral part of the Bydgoszcz flora and is likely to expand into segetal communities of agricultural and vegetable crops.

The Food and Growth of the Maskinonge (Esox masquinongy Mitchill) in Canadian Waters

1952 ◽  
Vol 8c (5) ◽  
pp. 347-368 ◽  
Author(s):  
Alan S. Hourston
Keyword(s):  
Yellow Perch ◽  
Fork Length ◽  
The Other ◽  
Western Region ◽  
Eastern Region ◽  
Weight Relationship ◽  
Straight Line ◽  
Central Regions ◽  
The Western Region ◽  
St Lawrence River

Maskinonge from three regions were studied: the Lake of the Woods district in Ontario (called Western); the Kawartha Lakes and Georgian Bay district in Ontario (Central) and the St. Lawrence River district in Quebec (Eastern). Examination of 202 stomachs, 81 containing food, showed the maskinonge to be a general carnivore, preying mainly on fish over 150 mm. in length. The families Percidae, Catostomidae, Ameiuridae, Centrarchidae, Hiodontidae, Esocidae and Cyprinidae were represented, along with at least one Cambarus. The yellow perch, Perca flavescens, was the species eaten most frequently in all three regions. A common white sucker (Catostomus commersonnii) was found in a stomach of the hybrid E. masquinongy × E. lucius. Examination of the teeth of each specimen showed that they were being continuously replaced throughout the summer season.Rate of growth varied with sex and locality. Females had a significantly faster rate of growth, both in length and in weight, than did males. Maskinonge from the Western Region were shorter and weighed less than fish of the same age from the other two regions. Maskinonge of the Eastern and Central Regions reached the legal size of 30 inches fork length during their fifth summer, but in the Western Region they did not attain this size until their seventh summer. The length-weight relationship appears to be the same in the Eastern and Central Regions, whereas maskinonge from the Western Region tended to be heavier than those of comparable lengths from the other two regions. In all regions the length-weight relationship was a straight line when plotted logarithmically, its slope being estimated as 3.26 in the Eastern Region. Sexual maturity occurs first between the ages of three and six years, or about 575 to 800 mm. fork length. Specimens of a E. masquinongy × E. lucius hybrid appeared to be infertile. They did not differ from the maskinonge specimens in their length-weight relationships but made faster growth than did the maskinonge from the same region.

Managing Weeds in Commercial Edamame Production: Current Options and Implications

Weed Science ◽  
2015 ◽  
Vol 63 (4) ◽  
pp. 954-961 ◽  
Author(s):  
Martin M. Williams
Keyword(s):  
Population Density ◽  
Weed Management ◽  
Crop Production ◽  
The United States ◽  
Global Market ◽  
Production Costs ◽  
Management Options ◽  
Weed Suppressive Ability ◽  
Hand Weeding ◽  
Density And Biomass

Edamame, a specialty food-grade soybean popular among health-conscious consumers, is growing in popularity worldwide. Despite a well-developed soybean industry, most edamame consumed in the United States is imported from Asia. Considerable interest exists in growing edamame domestically; however, weed interference is a major problem, and until recently, only a single herbicide was registered for use on the crop. The objectives of this work were (1) to compare effectiveness of weed management treatments that utilize herbicides currently registered for use on edamame or that may be registered in the near future, (2) to determine the significance of edamame cultivar on performance of these treatments, and (3) to identify potential relationships between the crop and weed. Ten different weed management treatments were tested in three edamame cultivars over a 3-yr period. All weed management treatments increased marketable pod yield relative to the nontreated control, but only treatments with saflufenacil orS-metolachlor combinations were comparable to the hand-weeded weed-free treatment. Of the treatments studied,S-metolachlor followed by imazamox was among the greatest yielding, had the least weed density and biomass, and did not reduce crop population density. Also, cultivars differed in their weed-suppressive ability. Path analysis indicated certain relationships were consistent across cultivars, such as weed population density having a direct negative association with crop biomass; however, other edamame–weed interactions were not identical across cultivars. Although more improvements are needed, the vegetable industry is beginning to have nascent weed management options in edamame, which will likely reduce reliance on hand weeding and result in crop-production costs that are more competitive in the global market.

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