scholarly journals Bait efficiency to monitor mandi (Pimelodus maculatus) in the tailrace of hydropower dams, Southeast Brazil

2021 ◽  
Vol 33 ◽  
Author(s):  
Alexandre Peressin ◽  
Rafael Couto Rosa Souza ◽  
Alexandre Lima Godinho
Keyword(s):  
Water Temperature ◽  
Linear Models ◽  
Environmental Variable ◽  
Fish Mortality ◽  
Catch Per Unit Effort ◽  
Discharge Water ◽  
Unit Effort ◽  
Hydropower Dams ◽  
Upper Paraná River ◽  
Pimelodus Maculatus

Abstract: Aim This study compared the efficiency of two baits (earthworm and cow heart) for monitoring the abundance of mandi catfish (Pimelodus maculatus) in the tailrace of hydropower dams, one of the commonly killed fish in turbine procedures. Methods Sampling occurred every two months from February 2014 to December 2015 at the Camargos and Itutinga hydropower dams, located in the upper Paraná River basin, using hooks baited with earthworm and cow heart. We used generalized linear models to test the influence of dam, bait type, dam outflow discharge, water temperature, transparency, and dissolved oxygen on mandi abundance, calculated as catch per unit effort. Results Most mandi (73%) were caught using earthworms but catch per unit effort of mandi for both baits showed the same pattern of seasonal variation at each dam. At both dams, individuals of mandi sampled using earthworms were smaller than those sampled using cow heart, and water temperature was the only environmental variable significantly associated with the catch per unit effort of mandi. Conclusions Both baits are efficient to monitor seasonal variations in mandi abundance, which is influenced by water temperature. Monitoring the abundance of mandi in the tailrace can help minimizing fish mortality by scheduling risky turbine procedures for periods of lower mandi abundance.

scholarly journals Influence plots and metrics: tools for better understanding fisheries catch-per-unit-effort standardizations

2011 ◽  
Vol 69 (1) ◽  
pp. 84-88 ◽  
Author(s):  
Nokome Bentley ◽  
Terese H. Kendrick ◽  
Paul J. Starr ◽  
Paul A. Breen
Keyword(s):  
New Zealand ◽  
Generalized Linear Models ◽  
Linear Models ◽  
Marine Science ◽  
Catch Per Unit Effort ◽  
Common Procedure ◽  
Explanatory Variables ◽  
Unit Effort

Abstract Bentley, N., Kendrick, T. H., Starr, P. J., and Breen, P. A. 2012. Influence plots and metrics: tools for better understanding fisheries catch-per-unit-effort standardizations. – ICES Journal of Marine Science, 69: 84–88. Standardization of catch per unit effort using generalized linear models (GLMs) is a common procedure that attempts to remove the confounding effects of variables other than abundance. Simple plots and metrics are described to assist understanding the standardization effects of explanatory variables included in GLMs, illustrated with an example based on New Zealand trevally (Caranx lutescens) data.

scholarly journals FAKTOR-FAKTOR PENTING YANG MEMPENGARUHI CPUE (Catch Per Unit Effort) PERIKANAN HUHATE BERBASIS DI BITUNG

2016 ◽  
Vol 22 (1) ◽  
pp. 43
Author(s):  
Agus Setiyawan ◽  
Lilis Sadiyah ◽  
Syarief Samsuddin
Keyword(s):  
Generalized Linear Model ◽  
Linear Models ◽  
Catch Per Unit Effort ◽  
Katsuwonus Pelamis ◽  
Fishing Vessels ◽  
Unit Effort ◽  
Landing Sites ◽  
Technical Factors ◽  
Live Bait ◽  
Logbook Data

<p>Bitung merupakan salah satu sentra pendaratan untuk perikanan huhate. Perikanan huhate bergantung terhadap ketersediaan umpan ikan hidup dan beberapa faktor teknis. Penelitian ini bertujuan untuk mengkaji faktor yang paling berpengaruh terhadap hasil tangkapan per upaya penangkapan (CPUE) ikan cakalang (<em>Katsuwonus pelamis - </em>SKJ). Pengambilan data primer dilaksanakan di atas kapal huhate dari Januari – Mei 2013 yang berbasis di Pelabuhan Perikanan Bitung – Sulawesi Utara. Data logbook kapal serta data harian kapal diperoleh pada saat melakukan pemancingan. Analisis data dilakukan dengan menggunakan analisis <em>Generalized Linear Models</em> (GLM), uji korelasi dan regresi sederhana. Hasil penelitian ini menunjukkan bahwa terdapat empat faktor signifikan berpengaruh terhadap nilai CPUE cakalang (SKJ). Faktor pertama adalah jenis umpan hidup yang digunakan berpengaruh secara signifikan terhadap CPUE SKJ (P&lt; 0,01). Jenis umpan hidup yang berpengaruh signifikan adalah jenis ikan layang dicampur dengan puri merah. Ketiga faktor lainya yaitu suhu permukaan laut (SPL), jumlah pemancing dan daerah penangkapan mempengaruhi CPUE SKJ dengan nilai P &lt; 0.05.</p><p><strong> </strong><em>Bitung is one of the main landing sites for pole and line fishing vessels. The<strong> </strong>pole and line fisheries depend on the availability of live fish bait and some technical factors. Objective of this study is to assess several factors that may influence catch per unit effort (CPUE) of skipjack (Katsuwonus pelamis – SKJ). Logbook data and record of daily vessel activities during fishing from January – May 2013 were used in the analysis. The data were analyzed using generalized linear model (GLM), correlation and regression. The results showed that type of live bait was significantly affect the SKJ CPUE (P&lt;0.01). Round scad (Decapterus spp) mixed with anchovy (Stelophorus spp) were giving higher SKJ CPUE as live bait. In addition, sea surface temperature, number of fishers, and fishing location also affect the SKJ CPUE with P &lt;0.05.   </em></p>

Status of swordfish stocks in the eastern Pacific Ocean estimated using data from Japanese tuna longline fisheries

2003 ◽  
Vol 54 (4) ◽  
pp. 393 ◽  
Author(s):  
Michael G. Hinton
Keyword(s):  
Pacific Ocean ◽  
Linear Models ◽  
Rapid Change ◽  
Eastern Pacific ◽  
Eastern Pacific Ocean ◽  
Catch Per Unit Effort ◽  
The North ◽  
Unit Effort ◽  
Using Data ◽  
Longline Fisheries

Swordfish (Xiphias gladius) are harvested in target and non-target fisheries throughout the eastern Pacific Ocean (east of 150°W). Analyses of trends in catch rates (catch per unit effort) standardized using general linear models indicate that there are two stocks in the eastern Pacific Ocean that have a north–south boundary at 5°S latitude; this is in striking contrast to the 10°N boundary that has generally been assumed by previous studies. Trends in standardized catch per unit effort have held relatively level for the north stock and have been increasing for the south stock. Considering these trends and given that annual catches have been fairly stable in the region since 1989, it appears that swordfish are not overfished in the eastern Pacific Ocean. Given the potential for rapid change in the nature of those gill-net and longline fisheries that are increasingly targeting swordfish in the region, the trends in standardized catch per unit effort should be closely monitored for indications of changing status of these stocks.

scholarly journals Evaluation of techniques used to protect tailrace fishes during turbine maneuvers at Três Marias Dam, Brazil

2012 ◽  
Vol 10 (4) ◽  
pp. 723-730 ◽  
Author(s):  
Francisco de Andrade ◽  
Ivo Gavião Prado ◽  
Raquel Coelho Loures ◽  
Alexandre Lima Godinho
Keyword(s):  
Statistical Power ◽  
Draft Tube ◽  
Fish Biomass ◽  
Catch Per Unit Effort ◽  
Sao Francisco River ◽  
Unit Effort ◽  
São Francisco River ◽  
Pimelodus Maculatus

Turbine dewatering and stop/startup may lead to the death of tons of fish at Brazilian power dams. The Três Marias Dam (TMD) on the São Francisco River has adopted two techniques to reduce the quantity of fish, mostly mandi (Pimelodus maculatus, Pimelodidae), affected by these maneuvers. They are: (i) spill before turbine dewatering to attract fish out of the tailrace, and (ii) fish screens in the stop log slots during turbine stop/startup to prevent fish from entering the draft tube. Here, we investigated whether spill and fish screens reduced the quantity of fish affected by turbine dewatering and stop/startup at TMD. We also determined whether the biomass of mandi trapped during turbine dewatering may be predicted by turbine discharge (Q) and/or catch per unit effort (CPUE) of mandis in the tailrace. Due to insufficient statistical power, our data were inconclusive as to whether spill attracted mandi out of the tailrace. We verified that the presence of fish screens significantly reduced the biomass of dead/moribund fish during turbine stop/startup. The biomass of mandis trapped in the draft tube during turbine dewatering was mainly influenced by Q (r² = 0.67), followed by CPUE (r² = 0.49). Since the trapped fish biomass correlated negatively with Q, we recommend that Q be maximized before turbine dewatering to reduce quantity of mandi trapped in the draft tube. The information presented here may be useful for reducing the quantity of fish affected by turbine maneuvers at TMD, as well as other dams.

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.

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