The den ecology and the effects of fishing pressure on the distribution of Octopus cyanea (Octopodidae: Mollusca) in Rodrigues lagoon, Rodrigues, Mauritius

The Guayas, located in Ecuador, is the largest basin in the Pacific Ocean and has an inventory of 123 native freshwater species. Most of these are endemic species that are threatened or at-risk due to anthropogenic activity and the modification, fragmentation, and destruction of habitats. The aim of this study was to determine the morphometric variation in three wild populations of Brycon dentex in the Guayas basin rivers and their connections to fishing management and environmental conditions. A total of 200 mature fish were captured, and 26 morphometric parameters were measured. The fishing policies (Hypothesis 1) and environmental conditions (Hypothesis 2) were considered fixed factors and were validated by t-tests. The morphological variation among the three populations (Hypothesis 3) was validated through a discriminant analysis. Fishing policies and resource management were found to generate morphological differences associated with body development. In addition, the environmental conditions were found to influence the size and structure of Brycon dentex populations. The analyzed populations were discriminated by the generated morphometric models, which differentiated Cluster 1 (Quevedo and Mocache rivers) with high fishing pressure from Cluster 2 (Pintado river) with medium–low fishing pressure. Morphometric differentiation by discriminant analysis is a direct and economic methodology that can be applied as an indicator of diversity maintenance.

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Estimation of abundance and spatial distribution of Panulirus argus using different methodologies in artificial shelter, trap and coral reef fisheries

Crustaceana ◽

10.1163/15685403-00003159 ◽

2013 ◽

Vol 86 (2) ◽

pp. 158-181 ◽

Cited By ~ 2

Author(s):

Raúl Cruz ◽

Carlos A. Borda

Keyword(s):

Spatial Distribution ◽

Spiny Lobster ◽

Panulirus Argus ◽

Fishing Gear ◽

Productive Capacity ◽

Fishing Pressure ◽

The West ◽

Effective Measure ◽

Protection Area ◽

Marine Protection

Estimates of spiny lobster stocks (Panulirus argus Latreille, 1804) represent a fundamental input for population assessment models and are, therefore, indispensable for proper management. In this study we analysed methodologies employed in the Gulf of Batabanó (Cuba) and Providencia and Santa Catalina (Colombian Caribbean) to estimate abundance (N) and stock productivity. We found evidence that the relative abundance (CPUE) for trap-like jaulones and skin diving in natural shelters was likely to remain high despite the decline in abundance (hyperstability). In contrast, the proportionality between CPUE and N was satisfactory in artificial shelters (Cuban pesqueros). Stock productivity was greater for jaulones (22 288 kg/km2) than for pesqueros (1309 kg/km2) or natural shelters (15.25 kg/km2), reflecting differences in the productive capacity of each type of fishing gear. In natural shelters the exploitable biomass is under great fishing pressure and the reproductive stock is likely to decrease. Thus, the West zone of Providencia and Santa Catalina, characterized by high-density seagrass and mangrove, should be designated a marine protection area to prevent a lobster fishing collapse. The most effective measure to revert the lobster fishing collapse in Cuba would be to ban the use of jaulones and liftable pesqueros, thereby reducing fishing intensity.

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Predicting Distribution, Production, Recreational Fishing Demand, and Conservation Concern of Indigenous Rainbow Trout Populations Based on Landscape Characteristics

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2020-0323 ◽

2021 ◽

Author(s):

Ariane Cantin ◽

Anne Farineau ◽

Darren J. Bender ◽

John R. Post

Keyword(s):

Population Dynamics ◽

Rainbow Trout ◽

Recreational Fishing ◽

Lake Area ◽

Fishing Pressure ◽

Stream Network ◽

Landscape Characteristics ◽

Rainbow Trout Oncorhynchus Mykiss ◽

Conservation Concern ◽

Patterns And Processes

Landscape ecology has mainly been integrated in aquatic science to describe patterns and processes in stream networks, but many lakes are connected through their tributaries and are also impacted by their position and connectivity within the watershed. This information on lake characteristics can be used by inland fisheries managers that oversee large landscapes comprising many waterbodies to predict: (1) species composition; (2) population dynamics and productivity; (3) recreational fishing pressure; and (4) overall conservation concern. We developed a methodology to assess these four items for the rainbow trout (Oncorhynchus mykiss) fishery of British Columbia by presenting a case study focused on the Clearwater and North Thompson watersheds using: the connectivity of lakes within the stream network to predict rainbow trout presence, stream order and lake area to estimate habitat availability and predict population dynamics and productivity (supply), and travel time from population centres to predict recreational fishing pressure (demand). By incorporating connectivity and environmental proxies of habitat, we explore patterns in population dynamics that can be used by fisheries managers to identify populations sensitive to overfishing or disturbance.

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Decline in Atlantic wolffish Anarhichas lupus in the North Sea: Impacts of fishing pressure and climate change

Journal of Fish Biology ◽

10.1111/jfb.14942 ◽

2021 ◽

Author(s):

Joanna K. Bluemel ◽

Simon Fischer ◽

David W. Kulka ◽

Christopher P. Lynam ◽

Jim R. Ellis

Keyword(s):

Climate Change ◽

North Sea ◽

Fishing Pressure ◽

The North ◽

The North Sea ◽

Anarhichas Lupus ◽

Atlantic Wolffish

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Taxonomic status of two morphotypes of Coryphaena hippurus (Perciformes: Coryphaenidae)

Neotropical Ichthyology ◽

10.1590/1982-0224-20160102 ◽

2017 ◽

Vol 15 (1) ◽

Cited By ~ 1

Author(s):

Alan Bonner ◽

Michelle R. Duarte ◽

Rosa C. C. L. Souza ◽

Cassiano Monteiro-Neto ◽

Edson P. Silva

Keyword(s):

Genetic Variation ◽

Taxonomic Status ◽

Brazilian Coast ◽

Gene Pools ◽

Fishing Pressure ◽

Allozyme Electrophoresis ◽

Coryphaena Hippurus ◽

Biological Matter ◽

Electrophoresis Method ◽

Definition Of

ABSTRACT Two Coryphaena hippurus morphotypes (dourado and palombeta) are found along the Brazilian coast and are considered by Rio de Janeiro’s fisherman and fishmongers as two different species. Furthermore, these morphotypes are commercialized under different values and suffer different fishing pressure. Therefore, a definition of their taxonomic status is an important economic and biological matter. In order to investigate this problem, allozyme electrophoresis method was undertaken for seventeen loci on 117 individuals of C. hippurus sampled at Cabo Frio/RJ (Brazil). The data indicate homogeneity between the morphotypes gene pools. Nevertheless, differences were found for genetic variation among dourado and palombeta, especially due to alcohol dehydrogenase locus. Natural selection hypothesis is discussed in explaining these findings.

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Socio-economic, technological and environmental drivers of spatio-temporal changes in fishing pressure

Marine Policy ◽

10.1016/j.marpol.2017.11.029 ◽

2018 ◽

Vol 88 ◽

pp. 189-203 ◽

Cited By ~ 5

Author(s):

Fabrice Stephenson ◽

Aileen C. Mill ◽

Catherine L. Scott ◽

Gavin B. Stewart ◽

Matthew J. Grainger ◽

...

Keyword(s):

Temporal Changes ◽

Environmental Drivers ◽

Fishing Pressure ◽

Spatio Temporal

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INTER-SPECIFIC COMPETITION AND FISHING EFFECT TO POPULATION DYNAMIC OF BALI SARDINE (SARDINELLA LEMURU)

Indonesian Fisheries Research Journal ◽

10.15578/ifrj.22.2.2016.85-90 ◽

2017 ◽

Vol 22 (2) ◽

pp. 85

Author(s):

Andhika Prima Prasetyo ◽

Rudy Masuswo Purwoko

Keyword(s):

Mortality Rate ◽

Population Dynamic ◽

Positive Response ◽

Fishing Pressure ◽

Fishing Mortality ◽

Precautionary Approach ◽

Dramatic Decline ◽

Stock Recruitment ◽

Juvenile Population ◽

Relationship Of

Stock-recruitment relationship of Bali sardine was investigated based on Beverton-Holt model by assuming inter-specific competition. Model is modified to incorporate the effect of fishing pressure that is density-independent to population dynamic by developing scenario fishing on adult and/or juvenile population. The results show that harvested adult the dramatic decline of recruitment supply. However, harvested juvenile is led to the positive response to population size, as an increase in fishing mortality rate will reduce competition mortality rate. Precautionary approach required by considering bipartite life cycle.

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Fisheries Reference Point and Stock Status of Croaker Fishery (Sciaenidae) Exploited from the Bay of Bengal, Bangladesh

Journal of Marine Science and Engineering ◽

10.3390/jmse10010063 ◽

2022 ◽

Vol 10 (1) ◽

pp. 63

Author(s):

Partho Protim Barman ◽

Md. Mostafa Shamsuzzaman ◽

Petra Schneider ◽

Mohammad Mojibul Hoque Mozumder ◽

Qun Liu

Keyword(s):

Bay Of Bengal ◽

Maximum Sustainable Yield ◽

Reference Points ◽

Production Model ◽

Fishing Pressure ◽

Surplus Production ◽

Stock Status ◽

Management Measures ◽

Production Models ◽

The Monte Carlo Method

This research evaluated fisheries reference points and stock status to assess the sustainability of the croaker fishery (Sciaenidae) from the Bay of Bengal (BoB), Bangladesh. Sixteen years (2001–2016) of catch-effort data were analyzed using two surplus production models (Schaefer and Fox), the Monte Carlo method (CMSY) and the Bayesian state-space Schaefer surplus production model (BSM) method. This research applies a Stock–Production Model Incorporating Covariates (ASPIC) software package to run the Schaefer and Fox model. The maximum sustainable yield (MSY) produced by all models ranged from 33,900 to 35,900 metric tons (mt), which is very close to last year’s catch (33,768 mt in 2016). The estimated B > BMSY and F < FMSY indicated the safe biomass and fishing status. The calculated F/FMSY was 0.89, 0.87, and 0.81, and B/BMSY was 1.05, 1.07, and 1.14 for Fox, Schaefer, and BSM, respectively, indicating the fully exploited status of croaker stock in the BoB, Bangladesh. The representation of the Kobe phase plot suggested that the exploitation of croaker stock started from the yellow (unsustainable) quadrant in 2001 and gradually moved to the green (sustainable) quadrant in 2016 because of the reduction in fishing efforts and safe fishing pressure after 2012. Thus, this research suggests that the current fishing pressure needs to be maintained so that the yearly catch does not exceed the MSY limit of croaker. Additionally, specific management measures should implement to guarantee croaker and other fisheries from the BoB.

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The Sea Cucumber Holothuria (Halodeima) atra (Jager, 1833), in South Tarawa Lagoon (Republic of Kiribati): Environmental Variability, Population Biology and Fishing Pressure

10.26686/wgtn.16985467.v1 ◽

2021 ◽

Author(s):

◽

Teatim Tamaroa

Keyword(s):

Repeated Measures ◽

Population Biology ◽

Sea Cucumber ◽

Environmental Variability ◽

Preliminary Investigation ◽

Organic Matter Content ◽

Biological Data ◽

Qualitative Assessment ◽

Current Status ◽

Fishing Pressure

<p>Holothuria atra or lollyfish is the most common sea cucumber in the Pacific and Indian Oceans. The current status of Holothria atra at 13 sites of South Tarawa lagoon (Republic of Kiribati) was established by using biological surveys and fishers' questionnaires. A preliminary investigation was conducted in order to assess how and why environmental variability and fishing pressure have affected the spatial and temporal distribution, mean abundant and mean size of this species at the sites. The 13 sites were selected randomly, and marked with a GPS on the map of South Tarawa. Sedimentary characteristics were determined for each site, and a qualitative assessment of sites health was made. Lollyfish length, biomass and abundance and transect density were calculated for each site. The weight of organic matter content and size of sediment sample were determined. Data were analysed using Kruskal-Walis (KW) and Repeated measures (RM) ANOVA tests. This thesis shows that the environmental variability could not offer reasons as to why the biological data of lollyfish varied from one site to another. However, other factors that were tested may explain the variation in biological data. Fishing pressure is one of those parameters that can regulate the lollyfish distribution and density and responses from local fishers indicate that fishing pressure is high and that the lollyfish resource is under considerable harvest pressure. Dissolved oxygen concentration in the water column and in the sediment may be also involved in the variation in lollyfish distribution and density but this was not tested. The findings of this research lead to a number of recommendations for the sustainable harvest of lollyfish in Tarawa lagoon. These include consideration of gear restrictions, lollyfish size and number limits, and the establishment of marine protected areas under co-management arrangements.</p>

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Gill net Selectivity and Fishing Pressure on Indian Major Carp in Thirumoorthy Reservoir, Tamil Nadu

Current World Environment ◽

10.12944/cwe.11.2.25 ◽

2016 ◽

Vol 11 (2) ◽

pp. 554-559 ◽

Cited By ~ 1

Author(s):

R Velmurugan ◽

N Neethiselvan ◽

B Sundaramoorthy ◽

Xavier Rayan ◽

Kalidoss Radhakrishnan ◽

...

Keyword(s):

Tamil Nadu ◽

Labeo Rohita ◽

Monsoon Season ◽

Catla Catla ◽

Fishing Pressure ◽

Catch Per Unit Effort ◽

Indian Major Carp ◽

Gill Net ◽

Dominant Fish ◽

Post Monsoon Season

In present study attempts has been made to document the fishing crafts and gears which operated in Thirumoorthy reservoir, Tamil Nadu. This investigation revealed, the post monsoon season had higher catch per unit effort of 11kg/boat/day by gillnet fishing and about 20 to 30kg/day in cast net. Catla catla has the dominant fish species and accounted about 58% followed by Cirrhinus mrigala (29%), Labeo rohita (12%) and Cyprinus carpio (2%) against the total landings. However, three species including the Tilapia, Rohu and Mrigala were found to constitute fishery in the cast net with mean CPUE of 20 to 30 kg per day.

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