Postimpoundment Change in Financial Performance of the Southern Indian Lake Commercial Fishery

1984 ◽  
Vol 41 (4) ◽  
pp. 715-719 ◽  
Author(s):  
M. W. Wagner
Keyword(s):  
Financial Performance ◽  
Cash Flow ◽  
Economic Viability ◽  
Lower Grade ◽  
Commercial Fishery ◽  
Catch Per Unit Effort ◽  
Capital Costs ◽  
Unit Effort ◽  
Traditional Fishing

Since impoundment of Southern Indian Lake in 1976, two economic surveys of the summer fishery have been carried out in 1977 and 1980. These surveys revealed a decrease in cash flow per fishing enterprise of 66%, from $3362 to $1141 (1980$), so that by 1980 the average enterprise could not meet its capital costs. The reduction in cash flow was mainly attributable to decreased gross revenues, due to decreased catch per unit effort on traditional fishing grounds, an increase in the proportion of lower grade whitefish in the catch, and a decrease in the average number of days spent fishing per enterprise. Consideration of a freight subsidy paid to fishermen further accented the decrease in financial performance. It is projected that by 1981 economic viability had worsened further.

Wind-Aided Recruitment of Canadian Arctic Cisco (Coregonus autumnalis) into Alaskan Waters

1988 ◽  
Vol 45 (5) ◽  
pp. 906-910 ◽  
Author(s):  
Robert G. Fechhelm ◽  
David B. Fissel
Keyword(s):  
Time Series ◽  
Canadian Arctic ◽  
Wind Data ◽  
Commercial Fishery ◽  
Catch Per Unit Effort ◽  
Longshore Currents ◽  
Unit Effort ◽  
Colville River ◽  
Young Of The Year ◽  
Mackenzie River

Summer wind data collected at Barter Island, Alaska, were compared with commercial fishery catches of arctic cisco (Coregonus autumnalis) at the Colville River, Alaska, for the period 1967–85. There was a significant (p = 0.036) association between yearly catch-per-unit-effort and the percent of easterly winds after adjusting for a 5-yr differential in the two time series. Results suggest that young-of-the-year fish which spawn in Canada's Mackenzie River are aided in their westward dispersal into Alaskan waters via wind-driven longshore currents. The greater the prevalence of easterly winds (westerly currents), the greater the recruitment. Increased recruitment manifests itself as an increase in Alaskan commercial fishery catch some 5-yr later when fish have grown to a size that renders them susceptible to commercial nets.

scholarly journals Assessing the stock status of holobenthic octopus fisheries: is catch per unit effort sufficient?

2009 ◽  
Vol 66 (3) ◽  
pp. 478-487 ◽  
Author(s):  
Stephen C. Leporati ◽  
Philippe E. Ziegler ◽  
Jayson M. Semmens
Keyword(s):  
Egg Production ◽  
Biological Information ◽  
Life History Strategies ◽  
Sufficient Information ◽  
Commercial Fishery ◽  
Catch Per Unit Effort ◽  
Stock Status ◽  
Unit Effort ◽  
The Status ◽  
Spawning Periods

Abstract Leporati, S. C., Ziegler, P. E., and Semmens, J. M. 2009. Assessing the stock status of holobenthic octopus fisheries: is catch per unit effort sufficient? – ICES Journal of Marine Science, 66: 478–487. Holobenthic and merobenthic octopus fisheries are commonly treated as biological equivalents, regardless of their contrasting life-history strategies. This is the consequence of a lack of species identification and relevant biological information for many species, which has led to a reliance on catch per unit effort (cpue) data for stock status assessments. Using the commercial Octopus pallidus fishery in southeast Australian waters as a case study, the reliability of commercial cpue data as an indicator of stock status for holobenthic octopus fisheries was assessed. To achieve this, cpue and biological information from a fixed position experimental research line were investigated for consistency in stock status patterns and compared with commercial fishery cpue trends. Research line results revealed that cpue could remain stable regardless of size-selective fishing mortality potentially impacting recruitment. The cpue in the commercial fishery was very seasonal and dominated by females during autumn, when both cpue and spawning periods peaked, so increasing the potential for negative fishery impacts on egg production. The inability of cpue to account for the effects of continual fishing pressure on recruitment or seasonal changes in sex-specific catchability, however, indicates that cpue alone cannot provide sufficient information on the status of a holobenthic octopus fishery.

Great Slave Lake: Effects of Exploitation on the Salmonid Community

1972 ◽  
Vol 29 (6) ◽  
pp. 741-753 ◽  
Author(s):  
J. J. Keleher
Keyword(s):  
Lake Trout ◽  
Fishing Effort ◽  
Study Data ◽  
Background Information ◽  
Commercial Fishery ◽  
Catch Per Unit Effort ◽  
Quota System ◽  
Great Slave Lake ◽  
Unit Effort ◽  
Average Size

A 20-year investigation commenced at the inception of the Great Slave Lake commercial fishery, and it is inferred that exploitation has been the sole cause of change in the fish stocks. Background information on the operation of the commercial fishery, the fishing regulations, and the study methods are provided. Lake whitefish, Coregonus clupeaformis, and lake trout, Salvelinus namaycush, have made up 94% of the commercial landings of 119 million lb during the period. Only three other species of the 25 occurring in the lake were usually marketed. Whitefish catches generally were distributed equally between the summer and winter seasons. Trout were caught almost exclusively during the summer season. The annual catch of these two species rose from 1.6 million lb in 1945 to a maximum of 9.4 million lb in 1949 then gradually decreased to about the 5 million lb level. The study data have been partitioned according to 13 statistical areas. Catch has not been in proportion to the extent of these areas. Whitefish catch has predominated in the western, Interior Lowlands, portion of the lake while trout catch has predominated in the eastern, Canadian Shield, portion. In various areas, the peak catches for whitefish were associated with peak catches for trout, indicating that both were the result of fishing down the virgin stocks. Summer catch per unit effort for each species has declined during the 20-year period. CPE varied with the statistical areas. The usual observed reduction for whitefish was 60% in contrast to 93% for trout. Estimated summer fishing effort and whitefish catch showed a direct relation but the relation for trout usually changed from a positive to a negative one. The average size of commercially caught fish has declined to about 2 lb for whitefish and 5 lb for trout. Information on catch per unit effort for other species indicates no evident explosions in their numbers, though ciscoes, Leucichthys spp., appear to have increased in abundance. Although the fishery was regulated in order to provide for maximum annual sustained yields, this has not been achieved for trout. Three opinions for this are offered. Exploitation under a pooled quota system for whitefish and trout is not favoured and a decrease in trout quota is recommended.

Qarun Lake fisheries; Fishing gears, Species composition and Catch per unit effort

2014 ◽  
Vol 18 (2) ◽  
pp. 39-49
Author(s):  
Sabry El-Serafy ◽  
Alaa El-Haweet ◽  
Azza El-Ganiny ◽  
Alaa El-Far
Keyword(s):  
Species Composition ◽  
Catch Per Unit Effort ◽  
Unit Effort ◽  
Fishing Gears ◽  
Lake Fisheries

scholarly journals Modeling of Lake Malombe Annual Fish Landings and Catch per Unit Effort (CPUE)

Forecasting ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 39-55
Author(s):  
Rodgers Makwinja ◽  
Seyoum Mengistou ◽  
Emmanuel Kaunda ◽  
Tena Alemiew ◽  
Titus Bandulo Phiri ◽  
...  
Keyword(s):  
Time Series ◽  
Information Criterion ◽  
Coefficient Of Determination ◽  
Series Data ◽  
Efficiency Coefficient ◽  
Arima Models ◽  
Catch Per Unit Effort ◽  
Annual Fish ◽  
Unit Effort ◽  
The Mean

Forecasting, using time series data, has become the most relevant and effective tool for fisheries stock assessment. Autoregressive integrated moving average (ARIMA) modeling has been commonly used to predict the general trend for fish landings with increased reliability and precision. In this paper, ARIMA models were applied to predict Lake Malombe annual fish landings and catch per unit effort (CPUE). The annual fish landings and CPUE trends were first observed and both were non-stationary. The first-order differencing was applied to transform the non-stationary data into stationary. Autocorrelation functions (AC), partial autocorrelation function (PAC), Akaike information criterion (AIC), Bayesian information criterion (BIC), square root of the mean square error (RMSE), the mean absolute error (MAE), percentage standard error of prediction (SEP), average relative variance (ARV), Gaussian maximum likelihood estimation (GMLE) algorithm, efficiency coefficient (E2), coefficient of determination (R2), and persistent index (PI) were estimated, which led to the identification and construction of ARIMA models, suitable in explaining the time series and forecasting. According to the measures of forecasting accuracy, the best forecasting models for fish landings and CPUE were ARIMA (0,1,1) and ARIMA (0,1,0). These models had the lowest values AIC, BIC, RMSE, MAE, SEP, ARV. The models further displayed the highest values of GMLE, PI, R2, and E2. The “auto. arima ()” command in R version 3.6.3 further displayed ARIMA (0,1,1) and ARIMA (0,1,0) as the best. The selected models satisfactorily forecasted the fish landings of 2725.243 metric tons and CPUE of 0.097 kg/h by 2024.

Environmental drivers of golden tilefish ( Lopholatilus chamaeleonticeps ) commercial landings and catch‐per‐unit‐effort

2021 ◽  
Author(s):  
Geneviève Nesslage ◽  
Vyacheslav Lyubchich ◽  
Paul Nitschke ◽  
Erik Williams ◽  
Churchill Grimes ◽  
...  
Keyword(s):  
Environmental Drivers ◽  
Catch Per Unit Effort ◽  
Unit Effort

Ecological and environmental factors affecting the foraging activity of the White-bellied Heron Ardea insignis (Hume, 1878) in Bhutan

2021 ◽  
pp. 1-18
Author(s):  
PEMA KHANDU ◽  
GEORGE A. GALE ◽  
SARA BUMRUNGSRI
Keyword(s):  
Relative Abundance ◽  
Habitat Restoration ◽  
Prey Species ◽  
Catch Per Unit Effort ◽  
Factors Affecting ◽  
Prey Biomass ◽  
Gravel Mining ◽  
Unit Effort ◽  
Prey Preferences ◽  
The Government

Summary White-bellied Heron Ardea insignis (WBH) is critically endangered, but we lack data on many aspects of its basic ecology and threats to the species are not clearly understood. The goal of this study was to analyse WBH foraging microhabitat selection, foraging behaviour, and prey preferences in two river basins (Punatsangchhu and Mangdechhu) in Bhutan which are likely home to one of the largest remaining populations of WBH. We also explored the relationship between the relative abundance of the WBH and prey biomass catch per unit effort within four foraging river microhabitats (pool, pond, riffle and run). Prey species were sampled in 13 different 100-m thalweg lengths of the rivers using cast nets and electrofishing gear. Riffles and pools were the most commonly used microhabitats; relative abundance was the highest in riffles. The relative abundance of WBH and prey biomass catch per unit effort (CPUE) also showed a weak but significant positive correlation (rs = 0.22). The highest biomass CPUE was observed in riffles while the lowest was found in the ponds. From the 97 prey items caught by the WBH, 95% of the prey were fish. The WBH mainly exploited three genera of fish (Garra, Salmo, and Schizothorax) of which Schizothorax (64%) was the most frequently consumed. This study provides evidence in support of further protection of critical riverine habitat and fish resources for this heron. Regular monitoring of sand and gravel mining, curbing illegal fishing, habitat restoration/mitigation, and developing sustainable alternatives for local people should be urgently implemented by the government and other relevant agencies. Further study is also required for understanding the seasonal variation and abundance of its prey species in their prime habitats along the Punatsangchhu and Mangdechhu basins.

Modelling catch per unit effort of the Black Volta near the Bui dam in Ghana

2016 ◽  
Vol 55 (2) ◽  
pp. 126-133
Author(s):  
Elliot H. Alhassan ◽  
Patrick K. Ofori-Danson ◽  
Francis K. E. Nunoo
Keyword(s):  
Catch Per Unit Effort ◽  
Unit Effort

Predation by southern sea lions (Otaria flavescens) on artisanal fishing catches in Uruguay

2002 ◽  
Vol 53 (8) ◽  
pp. 1161 ◽  
Author(s):  
Diana Szteren ◽  
Enrique Páez
Keyword(s):  
Significant Relationship ◽  
Shallow Waters ◽  
Fishing Gear ◽  
Artisanal Fishery ◽  
Artisanal Fishing ◽  
Catch Per Unit Effort ◽  
Sea Lion ◽  
Otaria Flavescens ◽  
Sea Lions ◽  
Unit Effort

Southern sea lions (Otaria flavescens) forage in coastal fishery grounds in shallow waters, where they interact with coastal fishing activities. The main objective of this research was to evaluate the predation of southern sea lions on artisanal fishery catches and thus determine whether interactions with sea lions affected catches. Between July 1997 and March 1998, we observed 53 fishing events onboard artisanal fishing boats in four localities. The presence and number of sea lions around the boat and the numbers of each fish species consumed by sea lions were recorded by an onboard observer. To estimate the damage caused by sea lions to fishery catches, we considered two scenarios, a conservative scenario and a maximized scenario. Predation on catches was observed in 50.9% of all the fishing events and up to four sea lions were sighted in 67.9% of fishing events. Considering a conservative scenario, predation varied from 0.8 to 9.1% of the catch per unit effort (CPUE) depending on the location. Considering the maximized scenario, predation varied from 3.4 to 46.2%. However, no significant relationship was found between CPUE and the number of sea lions in any locality or with either type of fishing gear. Furthermore, CPUE did not differ in the presence or absence of sea lion interactions and predation per unit effort did not vary between localities or seasons. It was concluded that neither the presence of sea lions nor the damage they cause were responsible for variations in CPUE.

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