Error Distribution Model to Standardize LPUE, CPUE and Survey-Derived Catch Rates of Target and Non-Target Species

Abstract: Indices of abundance are usually a key input parameter used for fitting a stock assessment model, as they provide abundance estimates representative of the fraction of the stock that is vulnerable to fishing. These indices can be estimated from catches derived from fishery-dependent sources, such as catch per unit effort (CPUE) and landings per unit effort (LPUE), or from scientific survey data (e.g., relative population number—RPN). However, fluctuations in many factors (e.g., vessel size, period, area, gear) may affect the catch rates, bringing the need to evaluate the appropriateness of the statistical models for the standardization process. In this research, we analyzed different generalized linear models to select the best technique to standardize catch rates of target and non-target species from fishery dependent (CPUE and LPUE) and independent (RPN) data. The examined error distribution models were gamma, lognormal, tweedie, and hurdle models. For hurdle, positive observations were analyzed assuming a lognormal (hurdle–lognormal) or gamma (hurdle–gamma) error distribution. Based on deviance table analyses and diagnostic checks, the hurdle–lognormal was the statistical model that best satisfied the underlying characteristics of the different data sets. Finally, catch rates (CPUE, LPUE and RPN) of the thornback ray Raja clavata, blackbelly rosefish Helicolenus dactylopterus, and common mora Mora moro from the NE Atlantic (Azores region) were standardized. The analyses confirmed the spatial and temporal nature of their distribution.

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Alternative error distribution models for standardization of catch rates of non-target species from a pelagic longline fishery: billfish species in the Venezuelan tuna longline fishery

Fisheries Research ◽

10.1016/j.fishres.2004.08.028 ◽

2004 ◽

Vol 70 (2-3) ◽

pp. 275-297 ◽

Cited By ~ 75

Author(s):

Mauricio Ortiz ◽

Freddy Arocha

Keyword(s):

Error Distribution ◽

Longline Fishery ◽

Target Species ◽

Distribution Models ◽

Pelagic Longline Fishery ◽

Catch Rates ◽

Pelagic Longline ◽

Tuna Longline

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Fish and invertebrate by-catch in the crab pot fishery in the Isle of Man, Irish Sea

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315417001643 ◽

2017 ◽

Vol 98 (8) ◽

pp. 2099-2111

Author(s):

Fikret Öndes ◽

Michel J. Kaiser ◽

Lee G. Murray

Keyword(s):

Irish Sea ◽

Target Species ◽

Catch Per Unit Effort ◽

Isle Of Man ◽

Ecosystem Effects ◽

By Catch ◽

Catch Rates ◽

Taxonomic Groups ◽

Catch Composition ◽

Autumn And Winter

Baited trap or pot fisheries are considered to have relatively few wider ecosystem effects on the marine environment, particularly when compared with towed mobile fishing gear. However, this assumption is rarely tested in the field. This study aimed to determine the composition of non-target species that occur in crustacean pots and to assess spatial and temporal differences in catches in the waters around the Isle of Man, Irish Sea. The data were collected using fishery independent surveys and a questionnaire study. Based on fishery independent surveys, a total of five taxonomic groups and 43 species occurred as by-catch. The dominant by-catch species was velvet crab Necora puber. The by-catch per unit effort (BPUE) for all of the non-target species was low particularly in comparison to towed bottom gear fisheries around the Isle of Man. BPUE of species composition varied considerably between different locations around the Isle of Man. The results of both the fishery independent and questionnaire data suggested that the by-catch rates varied with season with peak BPUE occurring in spring which then declined into autumn and winter. By-catch composition did not decrease significantly with an increasing target species catch. Overall, by-catch was low relative to target species catch which may be partially attributable to the use of escape panels in pot fisheries in the Isle of Man.

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Conservation, Ecology, and Management of Catfish: The Second International Symposium

Conservation, Ecology, and Management of Catfish: The Second International Symposium ◽

10.47886/9781934874257.ch12 ◽

2011 ◽

Keyword(s):

Population Dynamics ◽

Channel Catfish ◽

Mississippi River ◽

Upper Mississippi River ◽

Catch Per Unit Effort ◽

Blue Catfish ◽

Resource Monitoring ◽

Flathead Catfish ◽

Unit Effort ◽

Catch Rates

Abstract.—Using Long Term Resource Monitoring Program data collected from impounded (Pool 26) and unimpounded (Open River) reaches of the upper Mississippi River, we investigated population dynamics of flathead catfish Pylodictis olivaris, channel catfish Ictalurus punctatus, and blue catfish I. furcatus from random sites located in side channel border (SCB) and main channel border (MCB) habitats. Objectives were to (1) compare trends (1993–2007) of three catfishes collected in Pool 26 and Open River reaches of the upper Mississippi River, and (2) provide needed information to managers on population dynamics through time using a binary gear approach of active (i.e., daytime electrofishing) and passive gears (hoopnetting). Active gears resulted in a higher catch per unit effort (CPUE) of all catfishes in each habitat–reach combination as compared to passive gears. Passive gears resulted in negligible catches of blue catfish and flathead catfishes (e.g., mean of <1 fish/net night). Catch per unit effort using active gear resulted in a greater number of channel catfish captured in Pool 26 compared to the Open River, with Open River SCB habitat having the lowest CPUE in most years. Blue catfish in the Open River had a higher CPUE using active gear as compared to Pool 26, with the Open River MCB having the greatest CPUE. Flathead catfish had a higher CPUE in MCB habitat compared to SCB habitat, with the Open River MCB having the highest CPUE in most years. However, declining trends in flathead catfish appears to be occurring in Open River habitats while trends in flathead catfish appear to be slightly increasing in Pool 26. The most common length-classes captured were substock and stock-sized fish regardless of habitat, species, or reach. Trends for channel catfish were easily determined due to high catch rates; however, more monitoring and enhanced sampling is needed to accurately assess flathead catfish and blue catfish trends and to accurately determine demographics for all three species.

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Species Distribution Models (SDM) – A Strategic Tool for Predicting Suitable Habitats for Conserving the Target Species

Advances in Geospatial Technologies - Handbook of Research on Geographic Information Systems Applications and Advancements ◽

10.4018/978-1-5225-0937-0.ch017 ◽

2017 ◽

pp. 427-440

Author(s):

Balaguru Balakrishnan ◽

Nagamurugan Nandakumar ◽

Soosairaj Sebastin ◽

Khaleel Ahamed Abdul Kareem

Keyword(s):

Species Distribution ◽

Spatial Data ◽

Environmental Variables ◽

Species Distribution Models ◽

Species Distribution Model ◽

Distribution Model ◽

Suitable Habitat ◽

Target Species ◽

Distribution Models ◽

Suitable Habitats

Conservation of the species in their native landscapes required understanding patterns of spatial distribution of species and their ecological connectivity through Species Distribution Models (SDM) by generation and integration of spatial data from different sources using Geographical Information System (GIS) tools. SDM is an ecological/spatial model which combines datasets and maps of occurrence of target species and their geographical and environmental variables by linking various algorithms together, that has been applied to either identify or predict the regions fulfilling the set conditions. This article is focused on comprehensive review of spatial data requirements, statistical algorithms and softwares used to generate the SDMs. This chapter also includes a case study predicting the suitable habitat distribution of Gnetum ula, an endemic and vulnerable plant species using maximum entropy (MaxEnt) species distribution model for species occurrences with inputs from environmental variables such as bioclimate and elevation.

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Spatio-temporal distribution of longline catch per unit effort, sea surface temperature and Atlantic marlin

Marine and Freshwater Research ◽

10.1071/mf01255 ◽

2003 ◽

Vol 54 (4) ◽

pp. 409 ◽

Cited By ~ 15

Author(s):

C. Phillip Goodyear

Keyword(s):

Temporal Distribution ◽

Fishing Effort ◽

Sea Surface ◽

Sea Surface Temperatures ◽

Fishing Mortality ◽

Catch Per Unit Effort ◽

Surface Temperatures ◽

Unit Effort ◽

Spatio Temporal ◽

Catch Rates

Atlantic blue and white marlin are currently overfished, primarily as a result of bycatch in pelagic longlines directed at other species. One possible management measure to reduce fishing mortality on these species would be to restrict fishing effort in times and places with exceptionally high marlin catch per unit effort (CPUE). The International Commission for the Conservation of Atlantic Tunas maintains a database of catch and catch-effort statistics of participating nations. These data were analysed to determine whether the distribution of CPUE is sufficiently heterogeneous in time and space that such measures might provide meaningful management alternatives. The resulting distributions of catch rates were also contrasted with monthly average sea surface temperatures to examine the possible association between temperature and CPUE. The results show spatio-temporal heterogeneity in catch rates that may be partly explained by seasonal changes in sea surface temperatures. The time–area concentrations of high CPUE differ between the species. This observed heterogeneity might be exploited to develop alternatives for reducing fishing mortality for future management of the fisheries, but additional research is needed to refine the spatial scale of the analysis and to more fully understand the factors contributing to the observed distribution.

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Trade-offs in marine protection: multispecies interactions within a community-led temperate marine reserve

ICES Journal of Marine Science ◽

10.1093/icesjms/fsw166 ◽

2016 ◽

Vol 74 (1) ◽

pp. 263-276 ◽

Cited By ~ 8

Author(s):

Leigh M. Howarth ◽

Pascal Dubois ◽

Paul Gratton ◽

Matthew Judge ◽

Brian Christie ◽

...

Keyword(s):

Marine Reserve ◽

Fishing Effort ◽

Catch Per Unit Effort ◽

Physical Damage ◽

Unit Effort ◽

Trade Offs ◽

Commercially Important ◽

Low Levels ◽

Multispecies Interactions ◽

Catch Rates

This study investigated the effects of a community-led temperate marine reserve in Lamlash Bay, Firth of Clyde, Scotland, on commercially important populations of European lobster (Homarus gammarus), brown crab (Cancer pagurus), and velvet swimming crabs (Necora puber). Potting surveys conducted over 4 years revealed significantly higher catch per unit effort (cpue 109% greater), weight per unit effort (wpue 189% greater), and carapace length (10–15 mm greater) in lobsters within the reserve compared with control sites. However, likely due to low levels of recruitment and increased fishing effort outside the reserve, lobster catches decreased in all areas during the final 2 years. Nevertheless, catch rates remained higher within the reserve across all years, suggesting the reserve buffered these wider declines. Additionally, lobster cpue and wpue declined with increasing distance from the boundaries of the marine reserve, a trend which tag–recapture data suggested were due to spillover. Catches of berried lobster were also twice as high within the reserve than outside, and the mean potential reproductive output per female was 22.1% greater. It was originally thought that higher densities of lobster within the reserve might lead to greater levels of aggression and physical damage. However, damage levels were solely related to body size, as large lobsters >110 mm had sustained over 218% more damage than smaller individuals. Interestingly, catches of adult lobsters were inversely correlated with those of juvenile lobsters, brown crabs, and velvet crabs, which may be evidence of competitive displacement and/or predation. Our findings provide evidence that temperate marine reserves can deliver fisheries and conservation benefits, and highlight the importance of investigating multispecies interactions, as the recovery of some species can have knock-on effects on others.

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Not easy to catch: multiple covariates influence catch rates of brown shrimp (Crangon crangon L.), potentially affecting inferences drawn from catch and landings data

ICES Journal of Marine Science ◽

10.1093/icesjms/fsx203 ◽

2018 ◽

Vol 75 (4) ◽

pp. 1318-1328 ◽

Cited By ~ 2

Author(s):

Katharina Friederike Schulte ◽

Andreas Dänhardt ◽

Marc Hufnagl ◽

Volker Siegel ◽

Werner Wosniok ◽

...

Keyword(s):

North Sea ◽

Stock Assessment ◽

Brown Shrimp ◽

Catch Per Unit Effort ◽

Crangon Crangon ◽

Reproductive State ◽

Factors Affecting ◽

Southern North Sea ◽

Unit Effort ◽

Catch Rates

Abstract Brown shrimps (Crangon crangon) occur in high densities in the southern North Sea and support a large, but so far unmanaged fishery with >500 vessels. Cohort-based stock assessment is not possible, and catch per unit effort from scientific surveys and commercial landings are the only variables collected. Landings per unit effort are currently used to approximate the state of stock and to trigger catch restrictions, but, although decisive in interpreting unit catches or landings, factors affecting catch rates are rarely understood. Using data from two long-term (1997–2010) scientific surveys conducted in autumn and winter, respectively, in the southern North Sea and from a vertically resolving stow net deployed at two stations in the German Wadden Sea (2005–2007), we investigate the effects of season, reproductive state, size, tidal state, daylight, and water depth on catch rates of brown shrimp. Log-linear random intercept models revealed an influence of all factors examined on the catch rate. Depth had a clear effect on the composition of size and reproductive state, supporting the hypothesis that brown shrimp utilize selective tidal stream transport to migrate to depths preferred during certain periods within their life cycle. The vertical distribution of brown shrimp across the water column revealed that on average two thirds to three quarters of the brown shrimps were located above reach of the standard shrimp catching gear. Our findings indicate that multiple factors and interactions affect catch rates of brown shrimp and, thus, need to be accounted for when interpreting unit catches or landings for management purposes. We suggest that brown shrimps are not primarily demersal, and that stock size estimates solely relying on beam trawl data may underestimate the true density of shrimps per area.

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Interpreting catch per unit effort data to assess the status of individual stocks and communities

ICES Journal of Marine Science ◽

10.1016/j.icesjms.2006.05.008 ◽

2006 ◽

Vol 63 (8) ◽

pp. 1373-1385 ◽

Cited By ~ 271

Author(s):

Mark N. Maunder ◽

John R. Sibert ◽

Alain Fonteneau ◽

John Hampton ◽

Pierre Kleiber ◽

...

Keyword(s):

Relative Abundance ◽

Stock Assessment ◽

Limited Information ◽

Catch Per Unit Effort ◽

Fish Stocks ◽

Unit Effort ◽

Strategy Evaluation ◽

The Status ◽

Catch Rates ◽

Management Advice

AbstractDespite being one of the most common pieces of information used in assessing the status of fish stocks, relative abundance indices based on catch per unit effort (cpue) data are notoriously problematic. Raw cpue is seldom proportional to abundance over a whole exploitation history and an entire geographic range, because numerous factors affect catch rates. One of the most commonly applied fisheries analyses is standardization of cpue data to remove the effect of factors that bias cpue as an index of abundance. Even if cpue is standardized appropriately, the resulting index of relative abundance, in isolation, provides limited information for management advice or about the effect of fishing. In addition, cpue data generally cannot provide information needed to assess and manage communities or ecosystems. We discuss some of the problems associated with the use of cpue data and some methods to assess and provide management advice about fish populations that can help overcome these problems, including integrated stock assessment models, management strategy evaluation, and adaptive management. We also discuss the inappropriateness of using cpue data to evaluate the status of communities. We use tuna stocks in the Pacific Ocean as examples.

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Efficiency of fishing gears in the river Halda, Chittagong, Bangladesh

Journal of Fisheries ◽

10.17017/jfish.v3i3.2015.73 ◽

2015 ◽

Vol 3 (3) ◽

pp. 275 ◽

Cited By ~ 1

Author(s):

Mohammad Arshad-Ul-Alam ◽

Mohammad Ali Azadi

Keyword(s):

Analysis Of Variance ◽

Catch Per Unit Effort ◽

Pooled Data ◽

Unit Effort ◽

Gill Net ◽

Significant Difference ◽

Fishing Gears ◽

The Mean ◽

Catch Rates

To determine the catch efficiency of fishing gears, catch per unit effort (CPUE)data were collected for two years during January 2007 to December 2008 from the river Halda. Analyses were done to examine the variation of CPUE among gears, studied sections, months and years. The mean CPUE for pooled data of all gears was 2.247±0.265 kg.gear-1day-1 and 2.697±0.355 kg.gear-1day-1 for 2007 and 2008 respectively. Among eight gear categories, bag nets yielded the highest CPUE during 2007 (5.957±0.704 kg.gear-1day-1) and seine nets during 2008 (7.288±1.477 kg.gear-1day-1). Among 31 gear types, small meshed bag nets yielded the highest CPUE (18.065±6.660 and 15.69±4.479 kg.gear-1day-1 during 2007 and 2008 respectively). CPUE was highest during March-April and September-November periods. Analysis of variance showed significant difference among catch rates of different fishing gears. The CPUE differed significantly among different months for net fence, gill net, cast net and scoop net during 2007; and for seine net, net fence, bag net and cast net during 2008.

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