Genetic population structure of broad whitefish, Coregonus nasus, from the Mackenzie River, Northwest Territories: implications for subsistence fishery management

2010 ◽  
Vol 67 (6) ◽  
pp. 905-918 ◽  
Author(s):  
Les N. Harris ◽  
Eric B. Taylor
Keyword(s):  
Northwest Territories ◽  
Fishery Management ◽  
Management Strategies ◽  
River System ◽  
Population Subdivision ◽  
Genetic Population ◽  
Dna Variation ◽  
Scale Population ◽  
Population Structuring ◽  
Mackenzie River

We assayed microsatellite DNA variation among 1013 broad whitefish, Coregonus nasus , from 36 localities within the lower Mackenzie River (Northwest Territories, Canada) to provide the first assessment of fine-scale population structuring of broad whitefish in this large system. Among sampling locations, averaged across all loci, the number of alleles ranged from 3.00 to 6.71 and heterozygosity averaged 0.54. Population subdivision was generally low, but significant (θ = 0.026, P < 0.05), although pairwise comparisons indicated that overall significance was heavily influenced by comparisons between anadromous and lacustrine groups. Bayesian-based STRUCTURE analysis suggested that there are two main genetic groups within our study area: anadromous and lacustrine broad whitefish. A mixture analysis indicated that all populations contribute to the lower Mackenzie River subsistence fishery, yet catches were dominated by Peel River fish, highlighting the importance of this tributary. Our data also supported the idea that there are several units of conservation among Mackenzie River system broad whitefish populations and that management strategies should be implemented accordingly.

Major range extensions of anadromous salmonids and first record of chinook salmon in the Mackenzie River drainage

1983 ◽  
Vol 61 (9) ◽  
pp. 2183-2184 ◽  
Author(s):  
C. L. McLeod ◽  
J. P. O'Neil
Keyword(s):  
Northwest Territories ◽  
Chinook Salmon ◽  
Chum Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Grand Canyon ◽  
River System ◽  
First Record ◽  
Oncorhynchus Keta ◽  
River Drainage ◽  
Mackenzie River

Spawning migrations of chum salmon, Oncorhynchus keta (Walbaum), and Arctic cisco Coregonus autumnalis (Pallas), in the Liard River system (Mackenzie River drainage) within the Northwest Territories and British Columbia were documented during the period 1978 to 1981. These species have not been reported previously from the Liard River. The points of capture, as far upstream as the Grand Canyon of the Liard, represent a major southerly range extension in the Mackenzie River drainage and upstream migrations of nearly 2000 km from the Beaufort Sea. The first record of a chinook salmon, Oncorhynchus tshawytscha (Walbaum), from the Mackenzie River drainage is reported also. The specimen was collected in the Liard River, Northwest Territories, and was probably a stray, accompanying a spawning escapement of chum salmon.

scholarly journals RAD sequencing of common whelk, Buccinum undatum, reveals fine‐scale population structuring in Europe and cryptic speciation within the North Atlantic

2021 ◽  
Vol 11 (6) ◽  
pp. 2616-2629
Author(s):  
Jake Goodall ◽  
Kristen Marie Westfall ◽  
Hildur Magnúsdóttir ◽  
Snæbjörn Pálsson ◽  
Erla Björk Örnólfsdóttir ◽  
...  
Keyword(s):  
North Atlantic ◽  
Cryptic Speciation ◽  
Rad Sequencing ◽  
Fine Scale ◽  
Buccinum Undatum ◽  
The North ◽  
Scale Population ◽  
Population Structuring ◽  
The North Atlantic

scholarly journals Evaluating and Predicting the Effects of Land Use Changes on Hydrology in Wami River Basin, Tanzania

Hydrology ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 17 ◽  
Author(s):  
Sekela Twisa ◽  
Shija Kazumba ◽  
Mathew Kurian ◽  
Manfred F. Buchroithner
Keyword(s):  
Land Use ◽  
Water Resources ◽  
Assessment Tool ◽  
Swat Model ◽  
Land Use Changes ◽  
Management Strategies ◽  
River System ◽  
Least Squares Regression ◽  
Natural Forests ◽  
The Impact

Understanding the variation in the hydrological response of a basin associated with land use changes is essential for developing management strategies for water resources. The impact of hydrological changes caused by expected land use changes may be severe for the Wami river system, given its role as a crucial area for water, providing food and livelihoods. The objective of this study is to examine the influence of land use changes on various elements of the hydrological processes of the basin. Hybrid classification, which includes unsupervised and supervised classification techniques, is used to process the images (2000 and 2016), while CA–Markov chain analysis is used to forecast and simulate the 2032 land use state. In the current study, a combined approach—including a Soil and Water Assessment Tool (SWAT) model and Partial Least Squares Regression (PLSR)—is used to explore the influences of individual land use classes on fluctuations in the hydrological components. From the study, it is evident that land use has changed across the basin since 2000 (which is expected to continue in 2032), as well as that the hydrological effects caused by land use changes were observed. It has been found that the major land use changes that affected hydrology components in the basin were expansion of cultivation land, built-up area and grassland, and decline in natural forests and woodland during the study period. These findings provide baseline information for decision-makers and stakeholders concerning land and water resources for better planning and management decisions in the basin resources’ use.

New Complexities in Zoogeography and Taxonomy of the Pygmy Whitefish (Prosopium coulteri)

1972 ◽  
Vol 29 (12) ◽  
pp. 1772-1775 ◽  
Author(s):  
C. C. Lindsey ◽  
W. G. Franzin
Keyword(s):  
River System ◽  
Yukon Territory ◽  
Hudson Bay ◽  
The South ◽  
Bristol Bay ◽  
River Drainage ◽  
Bay Area ◽  
First Time ◽  
Mackenzie River

Pygmy whitefish (Prosopium coulteri) are recorded for the first time from the Peel–Mackenzie river drainage (Elliott Lake, Yukon Territory) and from the Hudson Bay drainage (Waterton Lakes, Alberta, in the South Saskatchewan–Nelson river system). The morphology of specimens from both localities contradicts the previously known pattern of a southeastern "low-rakered" and a northwestern "high-rakered" form (with the two forms occurring sympatrically in some lakes of the Bristol Bay area). Specimens from Elliott Lake, the most northerly known locality, resemble the southeastern form and those from Waterton Lakes the northwestern form. Both Waterton and Elliott lakes lie close to unglaciated refugia, suggesting that the species may have survived Wisconsin glaciation and diverged in several different watersheds.

scholarly journals Essential habitat for sardine juveniles in Iberian waters

2017 ◽  
Vol 81 (3) ◽  
pp. 351 ◽  
Author(s):  
Sílvia Rodríguez-Climent ◽  
Maria Manuel Angélico ◽  
Vítor Marques ◽  
Paulo Oliveira ◽  
Laura Wise ◽  
...  
Keyword(s):  
Fishery Management ◽  
Generalized Additive Models ◽  
Management Strategies ◽  
Coastal Region ◽  
Additive Models ◽  
Spawning Grounds ◽  
Significant Relationships ◽  
Juvenile Abundance ◽  
Spatial Differences ◽  
Core Areas

In a period when the Iberian sardine stock abundance is at its historical minimum, knowledge of the sardine juvenile’s distribution is crucial for the development of fishery management strategies. Generalized additive models were used to relate juvenile sardine presence with geographical variables and spawning grounds (egg abundance) and to model juvenile abundance with the concurrent environmental conditions. Three core areas of juvenile distribution were identified: the Northern Portuguese shelf (centred off Aveiro), the coastal region in the vicinity of the Tagus estuary, and the eastern Gulf of Cadiz. Spatial differences in the relationship between juvenile presence and egg abundances suggest that essential juvenile habitat might partially differ from the prevailing spawning grounds. Models also depicted significant relationships between juvenile abundance, temperature and geographical variables in combination with salinity in the west and with zooplankton in the south. Results indicate that the sardine juvenile distribution along the Iberian Peninsula waters are an outcome of a combination of dynamic processes occurring early in life, such as egg and larva retention, reduced mortality and favourable feeding grounds for both larvae and juveniles.

Assessing population sustainability and response to fishing in terms of aggregation structure for greenlip abalone (Haliotis laevigata) fishery management

2004 ◽  
Vol 61 (2) ◽  
pp. 247-259 ◽  
Author(s):  
Natalie A Dowling ◽  
Stephen J Hall ◽  
Richard McGarvey
Keyword(s):  
Egg Production ◽  
Fishery Management ◽  
Management Strategies ◽  
South Australia ◽  
Fertilization Success ◽  
Adult Density ◽  
Demographic Feature ◽  
Data Set ◽  
Functional Relationships ◽  
Aggregation Size

The greenlip abalone (Haliotis laevigata) population in Waterloo Bay, South Australia, has undergone collapse and fishery closure twice since 1978. A rich data set, including survey measures of degree of spatial aggregation, has been gathered over that time and provides a unique opportunity to identify factors accounting for persistence or collapse, an issue that is of significance to abalone fisheries worldwide. Statistical analyses of fishery and survey data were undertaken to infer functional relationships between catch, effort, recruitment, adult density, and extent of aggregation. Catch rates were hyperstable, an observation consistent with the targeting of large aggregations. Statistical analysis of recruitment showed a significant year effect, implying an environmental signal, and suggested that aggregation size impacts fertilization success. Aggregation size grew under closure, suggesting an impact of fishing on this demographic feature. Aggregative behaviour appears to be critical for subpopulation sustainability. Fishery collapse may be triggered by depletion of larger abalone aggregations by heavy fishing, resulting in declines in fertilized egg production. When heavy fishing coincides with unfavourable environmental conditions, recruitment may be insufficient to sustain the subpopulation. If aggregation is similarly critical for other subpopulations, management strategies could be adapted according to the extent of aggregation in each subpopulation.

Fish Stock Indicators as Measure for Sustainability

2015 ◽  
pp. 118-182 ◽  
Author(s):  
Violin S. Raykov ◽  
Ivelina Zlateva
Keyword(s):  
Black Sea ◽  
Fishery Management ◽  
Management Strategies ◽  
Age Determination ◽  
Reproductive Potential ◽  
Local Environment ◽  
Point Of View ◽  
The Black Sea ◽  
Fish Stock ◽  
Mortality Estimation

Particular species may be good indicators of specific environmental factors in their local environment. It was found that one of the main objectives for effective and sustainable management of the fish stocks is to make regular annual assessment of the parental stock biomass, length and weight growth, age determination, mortality estimation and reproductive potential estimation. The Black Sea sprat (Sprattus sprattus L.) is a key species in the Black Sea ecosystem. Small pelagic forage fish and especially local one with shared stocks are very important from ecological (key trophic level) and commercial (intensively exploited) point of view. Fishery management strategies must ensure that fishing mortality will not exceed that which corresponds to MSY, and that the biomass will not fall below a predefined threshold. The goal of the chapter is to define the main objectives and measures for sustainable sprat exploitation in order to be in favour of decision makers and fishery managers.

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