scholarly journals Seasonal variation in environmental DNA in relation to population size and environmental factors

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Andrew S. Buxton ◽  
Jim J. Groombridge ◽  
Nurulhuda B. Zakaria ◽  
Richard A. Griffiths
Keyword(s):  
Seasonal Variation ◽  
Environmental Factors ◽  
Population Size ◽  
Environmental Dna

Estimation of Catchabilities and Population Sizes of Lobsters

1963 ◽  
Vol 20 (1) ◽  
pp. 59-88 ◽  
Author(s):  
J. E. Paloheimo
Keyword(s):  
Environmental Factors ◽  
Population Size ◽  
Atlantic Coast ◽  
Temperature Data ◽  
New Method ◽  
Bottom Temperature ◽  
Population Size Estimates ◽  
Population Sizes ◽  
Estimate Population Size ◽  
Size Estimates

Techniques of estimating population size, level of fishing, and the degree of dependence of fishing success on environmental factors are examined on the basis of tagging, catch and effort data. A new method is developed to estimate population size from catch, effort, and temperature data when the catchability varies with temperature.The methods of estimation discussed are applied to data collected from a number of lobster fisheries on Canada's Atlantic coast. Analysis confirms a relationship between the catchability of lobsters and bottom temperature. Differences in this relationship are found between areas and between tagged and untagged lobsters within areas. It is suggested that these differences are attributable to the differences in densities as well as to aggregations of lobsters and fishing. The effect of these aggregations on population size estimates is considered.Calculated average catchabilities at comparable temperatures are different for different areas. These differences are correlated with the numbers of trap hauls per day per square miles fished. It is suggested that the differences in the catchabilities might be due to interactions between units of gear not predicted by the customary relationship between catch and effort.

EXAMINATION OF ENVIRONMENTAL FACTORS AFFECTING FISH ASSEMBLAGES IN THE DOWNSTREAM SEGMENT OF THE HAJI DAM USING ENVIRONMENTAL DNA ANALYSIS

2020 ◽  
Vol 76 (2) ◽  
pp. I_1309-I_1314
Author(s):  
Seiji MIYAZONO ◽  
Takao KODAMA ◽  
Yoshihisa AKAMATSU ◽  
Ryohei NAKAO ◽  
Satsuki TSUJI
Keyword(s):  
Environmental Factors ◽  
Dna Analysis ◽  
Fish Assemblages ◽  
Environmental Dna ◽  
Factors Affecting

Correlation between Chlorophyll-a Concentration and Environmental Factors in Jihongtan Reservoir

2011 ◽  
Vol 356-360 ◽  
pp. 959-962
Author(s):  
Ji Ping Ma ◽  
Cui Jie Rui ◽  
Jian Hua Ge ◽  
Yu Hua Liu ◽  
Zhi Wen Song ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Environmental Factors ◽  
Dissolved Oxygen ◽  
Statistical Method ◽  
Chlorophyll A ◽  
Potassium Permanganate ◽  
Total Nitrogen ◽  
Average Concentration ◽  
Low Concentrations ◽  
High Concentrations

Based on the Jihogntan reservoir’s monitoring data from 2006 to 2009, eutrophication of Jihongtan reservoir was assessed. The result showed that the nutrition level of the Jihongtan reservoir was middle in recent years. The average concentration of chlorophyll-a(Chla) was higher in summer and autumn than in spring and winter. The correlation between concentration of Chla and some environmental factors was studied by statistical method, and seasonal variation of Chla and the extent of eutrophication were also analyzed. The results showed that the correlations between Chla and total nitrogen(TN), dissolved oxygen(DO) and transparency were significantly negative, and that between Chla and total phosphorus(TP), temperature(T) and potassium permanganate index(COD Mn) were significantly positive. The growth of phytoplankton was promoted by TP and TN at low concentrations, and inhibited by TN at high concentrations.

Seasonal variation in numbers of the rabbit flea on the wild rabbit

Parasitology ◽  
1975 ◽  
Vol 70 (1) ◽  
pp. 103-118 ◽  
Author(s):  
A. R. Mead-Briggs ◽  
J. A. Vaughan ◽  
B. D. Rennison
Keyword(s):  
Seasonal Variation ◽  
Population Size ◽  
Wild Rabbit ◽  
Breeding Performance ◽  
Reproductive Condition ◽  
Juvenile Mortality ◽  
Relationship Of ◽  
Host Behaviour ◽  
The Relationship ◽  
Size And Structure

Samples of rabbits were obtained throughout each month over the 4-year period 1967–70. All fleas were removed, sexed and counted and the reproductive condition of the rabbits recorded. Rabbit fleas Spilopsyllus cuniculi (Dale) were present on both sexes of rabbit at all times of the year. In each year significantly high numbers of fleas were found on the rabbits in January, February, March and April and significantly low numbers in August, September and October. Mean flea counts were significantly higher on female rabbits than on males during April, May and June. During the rest of the year counts from each sex of host did not differ significantly. There were significant differences in flea numbers between years. More female than male fleas were found on both sexes of host throughout the year. The rabbit population sampled is shown to be typical of post-myxomatosis populations with regard to breeding performance and juvenile mortality. The relationship of the observed patterns of change in flea numbers to host and flea breeding and to host behaviour, population size and structure is discussed.

Spatiotemporal phytoplankton patterns in the Upper Mississippi River in response to seasonal variation in discharge and other environmental factors

River Systems ◽  
2015 ◽  
Author(s):  
Jillian K. Decker ◽  
John D. Wehr ◽  
Jeffrey N. Houser ◽  
William B. Richardson
Keyword(s):  
Seasonal Variation ◽  
Environmental Factors ◽  
Mississippi River ◽  
Upper Mississippi River

scholarly journals Changes in the reproductive parameters of female harp seals (Pagophilus groenlandicus) in the Northwest Atlantic

2009 ◽  
Vol 67 (2) ◽  
pp. 304-315 ◽  
Author(s):  
Becky Sjare ◽  
Garry B. Stenson
Keyword(s):  
Environmental Factors ◽  
Population Size ◽  
Sexual Maturity ◽  
Reproductive Parameters ◽  
Northwest Atlantic ◽  
Pagophilus Groenlandicus ◽  
Long Term Trends ◽  
The Mean ◽  
The 1950S

Abstract Sjare, B., and Stenson, G. B. 2010. Changes in the reproductive parameters of female harp seals (Pagophilus groenlandicus) in the Northwest Atlantic. – ICES Journal of Marine Science, 67: 304–315. Changes in female harp seal (Pagophilus groenlandicus) reproductive parameters from 1980 to 2004, and long-term trends since the early 1950s, are evaluated. Estimates of the total number of seals in the Northwest Atlantic declined from ∼3.0 million in the 1950s to 1.8 million in the early 1970s, then increased steadily to 5.5 million in 1996, at which relatively stable level it has remained since. Pregnancy rates increased from ∼86% in the 1950s to a high of 98% in the mid-1960s, then declined to ∼65–70% by the early 1990s; the rate then varied between 45 and 70% from 2000 to 2004. Concurrently, the mean age at sexual maturity decreased from 5.8 (s.e = 0.02) years in the mid-1950s to 4.1 (s.e. = 0.02) in the late 1970s, increased to 5.5 (s.e. = 0.03) years by the early 1990s, and peaked at 5.7 (s.e. = 0.01) in 1995. From 2000 to 2004, mean age varied from 4.9 (s.e. = 0.01) to 6.0 (s.e. = 0.01) years. Although the direction of change in each of the parameters was consistent with a density-dependent response, changes in population size explained relatively little of the variability observed, suggesting that other ecological or environmental factors were influential.

scholarly journals Seasonal variation in environmental DNA detection in sediment and water samples

PLoS ONE ◽  
2018 ◽  
Vol 13 (1) ◽  
pp. e0191737 ◽  
Author(s):  
Andrew S. Buxton ◽  
Jim J. Groombridge ◽  
Richard A. Griffiths
Keyword(s):  
Seasonal Variation ◽  
Water Samples ◽  
Dna Detection ◽  
Environmental Dna

Kill-off Patterns in Sheep and Goats: the Mandibles from Aşvan Kale

1973 ◽  
Vol 23 ◽  
pp. 281-303 ◽  
Author(s):  
Sebastian Payne
Keyword(s):  
Seasonal Variation ◽  
Weight Gain ◽  
Environmental Factors ◽  
Age Groups ◽  
Archaeological Sites ◽  
Meat Production ◽  
Young Males ◽  
Animal Bones ◽  
Relative Value ◽  
Mandibular Teeth

Reports on animal bones from archaeological sites often include information about the “kill-off pattern” for each species – i.e. the relative representation of different age-groups in the sample. Osteologists believe that this information can be used as evidence for whether an animal was wild or domesticated, and, if domesticated, about the way in which man managed the animal. In this paper a method is described for recording such data for sheep and goat using mandibles and mandibular teeth; the analysis and interpretation of such data is discussed using excavated samples from Aşvan Kale.When people keep sheep or goats, the age at which the animals are slaughtered depends on a range of factors: on the relative value placed on the different products, on the characteristics of the stock, and on a range of environmental factors – in particular, seasonal variation in the availability of grazing and feed. If meat production is the aim, most of the young males are killed when they reach the optimum point in weight-gain, only a few being kept for breeding.

Sign in / Sign up

Export Citation Format

Share Document