Zooplankton and Potential Fish Production in Lake Ontario

1984 ◽  
Vol 41 (9) ◽  
pp. 1303-1309 ◽  
Author(s):  
U. Borgmann ◽  
H. Shear ◽  
J. Moore
Keyword(s):  
Lake Ontario ◽  
Crustacean Zooplankton ◽  
Published Data ◽  
Total Production ◽  
Fish Production ◽  
Commercial Fish ◽  
Diacyclops Thomasi ◽  
Commercial Harvest ◽  
Recent Estimate ◽  
Fish Harvest

We calculated the annual production of epilimnetic crustacean zooplankton in Lake Ontario from data on the abundance of each species and its eggs, and from predictions of egg development times. Bosmina longirostris is the most productive species at the nearshore stations whereas Diacyclops thomasi is the most productive offshore. Total crustacean zooplankton production is fairly uniform throughout the lake, both nearshore and offshore, with the possible exception of somewhat reduced production at the western end of the lake. Average total production was estimated at 15 g∙m−2∙yr−1. Using a recent estimate of particle-size-conversion efficiency in Lake Ontario, obtained from data on contaminant concentrations in aquatic biota, we predicted potential fish production in the lake for various sizes of fish. From published data on the commercial fish harvest from 1910 to 1930, a time period when commercial production was at a maximum, we estimate that the past commercial harvest for pelagic species may have been 20% or more of our predicted potential production.

scholarly journals Characterization of the commercial fish production landed at Manaus, Amazonas State, Brazil

2003 ◽  
Vol 33 (1) ◽  
pp. 53-66 ◽  
Author(s):  
Vandick da Silva BATISTA ◽  
Miguel PETRERE JÚNIOR
Keyword(s):  
Amazon Basin ◽  
Annual Variation ◽  
Total Production ◽  
Fish Production ◽  
Seasonal Component ◽  
Commercial Fish ◽  
Colossoma Macropomum ◽  
Or Groups ◽  
Amazonas State

The present work aims to update a series of information about the regional fishing production, by presenting and characterizing the contribution of the different sub-systems of the Amazon basin to the catch landed at the main fishing market of Manaus, Brazil, from 1994 to 1996. Collectors specifically hired for this function registered key information on the fisheries. Thirty nine types or groups of fish were found in the fishing production landed. Jaraqui (Semaprochilodus spp.), curimatã (Prochilodus nigricans), pacu (Myleinae), matrinchã (Brycon cephalus), sardine (Triportheus spp.), aracu (Anostomidae) and tambaqui (Colossoma macropomum) were the most important items during three consecutive years. In 1994 these items summed up 91.6% of the total production; in 1995 and 1996 these values were, respectively, 85.3% and 86.4% of the total production. Tambaqui landed decreased remarkably during the period 1976-1996. There was a strong seasonal component in the production of the main species; jaraqui and matrinchã were mostly landed between April and June, while curimatã, pacu, and sardine were mostly landed during the dry season. Other important items showed a strong inter-annual variation in their production. The fishing production landed came mostly from the sub-system of the Purus River (around 30% of the total production). The subsystem of the Medium-Solimões contributed with an average of 15% and the sub-systems of the Madeira, Lower-Solimões, Upper-Amazon and Juruá, together contributed with 11.5% of the total production landed. Finally, the remaining sub-systems contributed with only 7.6% of the production.

Incidence and levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin in Lake Ontario commercial fish

1984 ◽  
Vol 18 (9) ◽  
pp. 719-721 ◽  
Author(s):  
John J. Ryan ◽  
Pui Yan. Lau ◽  
Jean C. Pilon ◽  
Dave. Lewis ◽  
Harry A. McLeod ◽  
...  
Keyword(s):  
Lake Ontario ◽  
Commercial Fish ◽  
Tetrachlorodibenzo P Dioxin

scholarly journals Economic viability of the piauçu Leporinus macrocephalus (Garavello & Britski, 1988) production

2004 ◽  
Vol 61 (2) ◽  
pp. 228-233 ◽  
Author(s):  
Leonardo Susumu Takahashi ◽  
Flavio Daolio Gonçalves ◽  
Janessa Sampaio de Abreu ◽  
Maria Inez Espagnoli Geraldo Martins ◽  
Antonio Carlos Manduca Ferreira
Keyword(s):  
Production Cost ◽  
Economic Valuation ◽  
Relative Magnitude ◽  
Productive Efficiency ◽  
Economic Viability ◽  
Selling Price ◽  
Total Production ◽  
Fish Production ◽  
Present Value ◽  
Fish Farms

Brazilian fish farms presented an accelerated development during the early 90's, mainly because of the increase in fee-fishing operations. To meet the demand of this market, fish production and supply became excessive and, as a consequence, the number of fee-fishing operations, farmers and the final selling price, decreased. This study analyzes the technical aspects, production cost, profitability and economic viability of the production of piauçu (L. macrocephalus) in ponds, based on information from a rural property. Feeding and fingerling costs amount to approximately 47.1% of the total production cost, representing together with the final selling price the most important factor affecting profitability. The payback period was 8.3 years, the liquid present value US$ 291.07, the internal return margin 9%, and the income-outcome ratio was 1.01, which represents an unattractive investment as a projection based on current conditions. The improvement in productive efficiency enhances the economic valuation index, and that the relative magnitude of cost and income are the most important points for the economic viability of the studied farm.

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

Structure and ecological production of the fish taxocene of a small floodplain system

1983 ◽  
Vol 61 (11) ◽  
pp. 2446-2464 ◽  
Author(s):  
Lawrence C. Halyk ◽  
Eugene K. Balon
Keyword(s):  
Species Richness ◽  
Fish Species ◽  
Local Extinction ◽  
Total Production ◽  
Fish Production ◽  
Resource Potential ◽  
Annulus Formation ◽  
Total Fish ◽  
Stream Pool ◽  
Pool Area

Fish species richness in floodplain pools results from species addition by spring invasion from the stream and species subtraction by local extinction throughout the summer. Local extinction is the more important of the two components. Nineteen floodplain pools (1 to 597 m2) and an adjacent section of Irvine Creek (43°44′ N, 80°25′ W), Ontario, Canada, were treated with a piscicide to test if the pools contribute significantly to the resource potential of the river basin. Altogether, 41 626 fishes of 20 species were collected. Number of days of stream connection in the spring was not significantly correlated with fish species richness in the pools (P < 0.10). A significant correlation (P < 0.05, r = 0.7413) was found between species richness and the logarithm of pool area. The total fish production for the Irvine Creek section, adjusted to account for dominant and nondominant species, was 298 kg∙ha−∙year−1. Production for this site was underestimated by 49% when weights and densities were backcalculated to time of annulus formation. Total production estimates of the floodplain pools ranged from 135 to 314 kg∙ha−1∙year−1. Stream connection duration affects pool fish production by regulating accessibility to the young of stream spawning species. Floodplain pools are beneficial to the Irvine Creek system. As nursery areas, floodplain pools produce fish biomass which can return to the stream during periods of stream–pool connection. These pools may also act as fish havens if catastrophic stream mortality occurs.

Bacterial Counts of Commercial Fish Diets

1971 ◽  
Vol 28 (8) ◽  
pp. 1185-1189 ◽  
Author(s):  
T. J. Trust
Keyword(s):  
Fluorescent Pseudomonads ◽  
Total Count ◽  
Aerobic Bacteria ◽  
Fish Production ◽  
Commercial Fish ◽  
Fish Diets ◽  
Thermophilic Species ◽  
Aerobic And Anaerobic ◽  
Spore Forming Bacteria ◽  
Representative Samples

Two diets formulated and offered for commercial fish production were examined to determine their microbial burden. The total count of aerobic bacteria ranged from 103 to 107 bacteria per gram of diet. The diets contained psychrophilic and thermophilic species and up to 104 aerobic and anaerobic spore-forming bacteria per gram. Enterococci and members of the Enterobacteriaceae, including species of Salmonella, were also present. Fluorescent pseudomonads were detected in 18 of the 47 samples tested, Proteolytic, amylolytic, lipolytic, and haemolytic organisms were shown to be present in measurable numbers. The total viable aerobic count did not change markedly on storage of representative samples at 4, 20, or 30 C.

Particle-Size-Conversion Efficiency and Contaminant Concentrations in Lake Ontario Biota

1983 ◽  
Vol 40 (3) ◽  
pp. 328-336 ◽  
Author(s):  
Uwe Borgmann ◽  
D. M. Whittle
Keyword(s):  
Particle Size ◽  
Body Size ◽  
Conversion Efficiency ◽  
Food Chain ◽  
Lake Ontario ◽  
Dry Weight ◽  
Growth Efficiency ◽  
Fish Production ◽  
The Relationship ◽  
Zooplankton Production

The particle-size-conversion efficiency (log food consumption/production divided by log predator prey size ratio) is shown to be directly related to the relationship between the concentration of persistent contaminants accumulated primarily through the food chain and body size for organisms in pelagic ecosystems. The difference between particle-size-conversion efficiency for biomass and that for the contaminant gives the slope of the relationship between log contaminant concentration and log body size. This provides a useful theoretical framework for analyzing contaminant concentrations in aquatic biota without the need for specifying trophic level but still incorporating the idea of food chain accumulation. Concentrations of PCB, DDT, and mercury were examined in aquatic organisms from Lake Ontario, ranging in size from zooplankton to large salmonids (a 108 -fold range in dry weight). The slope of the double log plot of concentration versus weight varied from 0.20 to 0.22 for PCB and DDT and was approximately equal to 0.13 for mercury. This indicates that mercury is accumulated less efficiently through the food chain than PCB or DDT. After correcting for incomplete uptake and retention of the contaminant, an estimate of particle-size-conversion efficiency for biomass of about 0.26 was obtained, which agrees reasonably well with previous estimates obtained from growth efficiency experiments and analysis of particle-size spectra. These calculations indicate that potential fish production in Lake Ontario is ~ 120-fold lower than zooplankton production (for fish averaging 108-fold larger in body size as compared to zooplankton).Key words: particle-size-conversion efficiency, PCB, DDT, mercury, zooplankton production, fish production

Sanitation of fish farms and prevention of fish diseases by pond drying with the use of fish and grass rotation

2016 ◽  
Vol 3 (3) ◽  
pp. 380-384
Author(s):  
Наумова ◽  
A. Naumova ◽  
Наумова ◽  
A. Naumova
Keyword(s):  
Comparative Research ◽  
Silver Carp ◽  
Fish Farm ◽  
Fish Production ◽  
Fish Ponds ◽  
Fish Farms ◽  
Commercial Fish ◽  
Causative Agents ◽  
Annual Frequency ◽  
One Year

Objective of research: to present the actuality and novelty of application of fish and grass “rotation” because this allows to reveal new data on pond drainage planning which is the most effective in sanitation of the fish farm. Materials and methods: to determine the most effective cycle for the summer drying of ponds, we studied ecological and epizootological features of fishing ponds, which had been used after drying within 1 and 5 years. As research object served 8 fish ponds: 4 drained ponds under crop (40 ha), 4 — overflowed (40 ha) and filled with one-year carps (2,5-З thousand ind./ha) and silver carps (1,2-1,4 thousand ind./ha). Results and discussion: The results of comparative research on anti-epizootic efficacy of pond drying at different periodicity of 1 and 5 years with the use of fish and grass “rotation” are provided. Data on decreased invasion of fishes (carp, silver carp) by parasites, absence of causative agents of infection, improved blood indicators, increased fish production at annual pond drying (with the use of fish and grass “rotation”) compared with the pond drying of 5 year periodicity are presented. Advantages of economic efficacy of the annual frequency of pond drying are confirmed: twice increased commercial fish production; reduced expenses for purchase of food (own barley and wheat production), drugs, disinfectants, fertilizers that allow increasing economic revenue and making profit.

Mercury concentrations of the axial muscle tissues of some marine fishes of the continental shelf adjacent to Tasmania

1985 ◽  
Vol 36 (4) ◽  
pp. 509 ◽  
Author(s):  
JD Thomson
Keyword(s):  
Total Mercury ◽  
Marine Fishes ◽  
Management Tool ◽  
Published Data ◽  
Organic Mercury ◽  
Commercial Fish ◽  
Total Length ◽  
Muscle Tissues ◽  
Wet Weight ◽  
Health Regulations

The mercury concentrations of 35 commercial and potentially commercial fish species from Tasmanian waters were determined. Four species had mean total mercury concentrations above 0.5 mg kg-1 wet weight and in all four there were individuals with concentrations above 1.5 mg kg-1 wet weight. Two species of shark, Parascyllium ferrugineum and Cephaloscyllium laticeps (with sample sizes of 4 and 1, respectively), had total mercury concentrations above the limit of a mean of 1.0 mg kg-1 wet weight set by the Tasmanian Public Health regulations. Concentrations in the species were compared with published data. Organic mercury concentrations in different species ranged from 40 to 96% of the total mercury concentrations. In fewer than half the species were total mercury concentration and total length or weight significantly correlated, indicating that neither total length nor weight could be used as a universal management tool to control human mercury intake from fish consumption.

THE CASE FOR RESEARCH ON THE EFFECTS OF ZEBRA MUSSELS IN LAKE ERIE: VISUALIZATION OF INFORMATION FROM AUGUST AND SEPTEMBER 1993

1994 ◽  
Vol 02 (04) ◽  
pp. 467-480 ◽  
Author(s):  
MURRAY N. CHARLTON
Keyword(s):  
Energy Flow ◽  
Zebra Mussel ◽  
Lake Erie ◽  
Nutrient Loading ◽  
Zebra Mussels ◽  
Fish Production ◽  
Management Options ◽  
Ecosystem Effects ◽  
Potential Loss ◽  
Fish Harvest

Recent concern about the effects of Zebra mussels has centred on potential loss of fish production and potential loss of fish edibility. The mussels are thought to cause these effects by diversion of energy flow and alteration of contaminant processing. Because management options are limited to controls on nutrients and fish harvest/stocking, it is important to determine the extent and degree of Zebra Mussel effects. Some effects of the mussels are obvious in sheltered shallow areas but the effects on the whole ecosystem are not known. A series of research surveys done in 1993 is reported in this paper. The effects of the mussels seem to result in a loss of about 25 % of the standing algal biomass in some areas. Although an attempt was made to visit many areas of the lake, more extensive work is needed to find whole ecosystem effects. The difficulty in delineating the effects of the mussels is caused by the coincidental achievement of nutrient loading goals. Because the distribution of zebra mussels is uneven their effects may be found through extensive spatial surveys.

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