Standing Stock and Production of Fish in a Cascading Lake System on the Canadian Shield

1985 ◽  
Vol 42 (7) ◽  
pp. 1315-1320 ◽  
Author(s):  
John R. M. Kelso
Keyword(s):  
Standing Stock ◽  
Canadian Shield ◽  
Published Data ◽  
Fish Biomass ◽  
Fish Production ◽  
Large Fish ◽  
Lake Depth ◽  
Lake System ◽  
Total Fish ◽  
Shield Lakes

To examine factors influencing fish biomass and production, I carried out a multiple mark and recapture program in a cascading lake system on the Canadian Shield. Standing stock and production were determined for all "large" fish (vulnerable to the gear in use) in the system. Total fish biomass (range 5.2–24.8 kg∙ha−1) decreased with progression downstream and with increasing depth. Production ranged from approximately 2.2 to 6.6 kg∙ha−1∙yr−1 and operated in a manner identical to standing stock. Salmonid flesh production, however, formed a greater proportion to overall fish production in the downstream, less productive lakes. Biomass was strongly influenced by lake depth in this watershed, and this was confirmed by examination of other published data for fish biomass and production in Shield lakes.

Cadmium concentrations of crustacean zooplankton of acidified and nonacidified Canadian Shield lakes

1990 ◽  
Vol 24 (9) ◽  
pp. 1367-1372 ◽  
Author(s):  
Norman D. Yan ◽  
Gerald L. Mackie ◽  
Peter J. Dillon
Keyword(s):  
Canadian Shield ◽  
Crustacean Zooplankton ◽  
Shield Lakes

Total Dissolved Solids as a Predictor of Lake Biomass and Productivity

1983 ◽  
Vol 40 (1) ◽  
pp. 92-95 ◽  
Author(s):  
E. E. Prepas
Keyword(s):  
Chlorophyll A ◽  
Significant Relationship ◽  
Positive Relationship ◽  
Biomass Productivity ◽  
Total Dissolved Solids ◽  
Fish Production ◽  
Dissolved Solids ◽  
Significant Positive Relationship ◽  
Morphoedaphic Index ◽  
Shield Lakes

Total dissolved solids (TDS) and chlorophyll a were not related in 25 lakes which were all off the Precambrian Shield. Both on-shield and off-shield lakes were included in the previous reports which showed a significant relationship between TDS and productivity. When data from on-shield and off-shield lakes were analyzed separately, there was no significant positive relationship between TDS and lake biomass or productivity. It was also shown that mean depth ([Formula: see text]) was as good a predictor of fish production as the TDS: [Formula: see text] ratio, the morphoedaphic index.Key words: TDS, biomass, productivity, morphoedaphic index, chlorophyll a, lakes

Flood basalts, dike swarms and sub-crustal flow

1968 ◽  
Vol 5 (1) ◽  
pp. 93-96 ◽  
Author(s):  
Paul M. Clifford
Keyword(s):  
Unsteady Motion ◽  
Canadian Shield ◽  
Published Data ◽  
Flood Basalts ◽  
Crustal Movements ◽  
Geologic Time ◽  
Dike Swarms ◽  
Convective Cells

A review of published data on flood basalts and diabase dike swarms suggests that they are related in origin, typically being developed in zones of crustal tension induced by sub-crustal flow. Perhaps, therefore, these basaltic effusions may be used to map convective cells in the mantle for various periods during geologic time. The inferred pattern of sub-crustal movements, particularly for the southern continents, is seen to be complicated, both temporarily and spatially, and is strongly suggestive of unsteady motion. Dikes of the Canadian Shield permit inferences about the site of convective cells back to 2150 million years.

scholarly journals The role of predator removal by fishing on ocean carbon dynamics

2021 ◽  
Author(s):  
Rick Stafford ◽  
Zach Boakes ◽  
Alice Hall ◽  
Georgia Jones
Keyword(s):  
Predatory Fish ◽  
Fish Biomass ◽  
Predator Removal ◽  
High Productivity ◽  
Respiration Rates ◽  
Total Fish ◽  
Ocean Carbon ◽  
Global Carbon ◽  
Phytoplankton Photosynthesis

Abstract The ocean is a net sequester of carbon dioxide, predominantly through low biomass, high productivity phytoplankton photosynthesis. Selective removal of predatory fish through extractive fishing alters the community structure of the ocean, with an increased biomass of more productive, low trophic level fish and higher overall respiration rates, despite possible decreases in total fish biomass. High pressure fishing on predators may result in as much as a 19% increase in respiration from fish communities and could prove highly significant in global carbon budgets.

Calibration of the zooplankton community size spectrum as an indicator of change in Canadian Shield lakes

2019 ◽  
Vol 76 (12) ◽  
pp. 2268-2287
Author(s):  
Lauren Emily Barth ◽  
Brian John Shuter ◽  
William Gary Sprules ◽  
Charles Kenneth Minns ◽  
James Anthony Rusak
Keyword(s):  
Zooplankton Community ◽  
Canadian Shield ◽  
Rate Of Change ◽  
Crustacean Zooplankton ◽  
Size Spectrum ◽  
Community Size ◽  
Mean Values ◽  
Sampling Protocols ◽  
Stable Characteristic ◽  
Shield Lakes

Developing the crustacean zooplankton community size spectrum into an indicator of change in lakes requires quantification of the natural variability in the size spectrum related to broad-scale seasonal, annual, and spatial factors. Characterizing seasonal patterns of variation in the size spectrum is necessary so that monitoring programs can be designed to minimize the masking effects that seasonal processes can have on detecting longer-term temporal change. We used a random effects model to measure monthly, annual, and interlake variability in the slope (i.e., relative abundance of small and large organisms) and centered height (i.e., total abundance) of the crustacean zooplankton normalized abundance size spectrum from 1981 to 2011 among eight Canadian Shield lakes. Consistent with theoretical predictions, the slope was a relatively stable characteristic of the zooplankton community compared with the height, which varied significantly among lakes. We identified a seasonal signal in height and slope and used a mixed effects model to characterize the linear rate of change from May to October; there was an overall decline in height and an overall increase in slope. Seasonal variance was greater than annual variance for both the height and the slope, suggesting that long-term monitoring of lakes and interlake comparisons using zooplankton size spectra should be based on temporally standardized sampling protocols that minimize the effects of seasonal processes. We recommend sampling the zooplankton community in midsummer because this results in size spectrum estimates close to seasonal mean values.

scholarly journals Current status and barriers to fisheries comanagement: Evidences from an Oxbow lake of Bangladesh

2018 ◽  
Vol 46 (2) ◽  
pp. 105-116
Author(s):  
Md Monirul Islam ◽  
Chandan Kar ◽  
Goutam Kumar Kundu ◽  
Gouri Mondal ◽  
Mohammad Shahneawz Khan
Keyword(s):  
Sustainable Management ◽  
Common Property ◽  
Secondary Data ◽  
Oxbow Lake ◽  
Current Status ◽  
Fish Production ◽  
Group Discussions ◽  
Social Barriers ◽  
Institutional Economic ◽  
Total Fish

Co-management of common property aquatic habitats are increasingly implemented with a view to increasing fish production, ensuring fishers’ rights and to conserve biodiversity. This study investigates the current status and identifies barriers to fisheries management in an oxbow lake (baor) at Jessore district, Bangladesh. Using interviews, focus group discussions and secondary data, this study revealed that both capture and culture fisheries are practised at the same time at the same water-body. As the wetland was used solely for capture fisheries before, the introduction of aquaculture practice has increased the total fish production and income for some people. However, it has reduced the access to poor fishers and fish biodiversity. Particularly the biodiversity of Channa sp, Puntius sp, Mastacembelus sp, Mystus sp, and Colisa fasciatus has been reduced. A range of climatic, institutional, economic and social barriers have facilitated the reduced access of poor fishers and biodiversity. To overcome the barriers and ensure sustainable management of the baor this study proposes to implement a fair leasing system, increase financial and human resources together with an ecosystem-based approach to baor management. Bangladesh J. Zool. 46(2): 105-116, 2018

scholarly journals Impact of aqua drugs and chemicals on the recoveries of fish diseases and total fish production in Sherpur region of Bangladesh

2016 ◽  
Vol 1 (3) ◽  
pp. 600-606
Author(s):  
Gias Uddin Ahmed ◽  
Mohammad Nurul Alam ◽  
Md Mamunur Rahman
Keyword(s):  
Potassium Permanganate ◽  
Total Production ◽  
Fish Production ◽  
Average Recovery ◽  
Fish Diseases ◽  
Disease Information ◽  
Different Types ◽  
Liver And Kidney ◽  
Total Fish ◽  
The Impact

The present study was conducted to investigate the impact of aqua-drugs and chemicals on fish health and total fish production in Sherpur region, Bangladesh from July 2014 to June 2015. Forty nine different types of aqua-drugs and chemicals were recorded in the study area; among those sixteen types mainly ADDIC drugs and chemicals were widely used by the farmers for treatment of different fish diseases. It was recorded that GR Plus, Active Blue with Copper sulphate, ID Plus, Aqua c vit and H. vit plus were used for the treatment of EUS in Pangus, Shing and Thai koi which had an average recovery of 80-90%. For the treatment of Edwardsiellosis in Pangus and Thai koi, farmers used GR Plus, ID Plus, OTC power, Aqua c vit, H.vit plus and potassium permanganate which had an average recovery of 75-80%, and for the treatment of dropsy in Thai koi and Shing GR Plus, ID Plus, OTC power, Aqua c vit, H.vit plus and potassium permanganate were used which had an average recovery of 75-85%. Histopathology of liver and kidney of fishes were almost normal in control ponds, whereas, in fish organs from drug treated ponds had pathological changes like necrosis, pyknotic cells, hemorrhage, fat droplet, ilets of langerhens, degeneration of kidney tubules and vacuums. Total production of Thai koi, Shing and Pangus was 10,000 kg/acre, 10,000 kg/acre, and 13,000 kg/acre in drugs treated ponds; whereas, such value was 5,000 kg/acre, 4,500 kg/acre and 6,500 kg/acre in non-treaded ponds, respectively in the study areas. In control ponds, mortality rate was comparatively high and production was also low than drugs treated ponds. End of the experiment, it was observed that efficacy of drugs of Aqua Drug and Disease Information Centre (ADDIC) was excellent.Asian J. Med. Biol. Res. December 2015, 1(3): 600-606

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