scholarly journals On the relationship between squid and the environment: artisanal jigging for Loligo plei at São Sebastião Island (24°S), southeastern Brazil

2010 ◽  
Vol 67 (7) ◽  
pp. 1353-1362 ◽  
Author(s):  
Felippe A. Postuma ◽  
Maria A. Gasalla
Keyword(s):  
Environmental Variables ◽  
Linear Models ◽  
Environmental Data ◽  
Southeastern Brazil ◽  
Small Scale ◽  
Lunar Phase ◽  
Catch Per Unit Effort ◽  
Chl A ◽  
Small Scale Fisheries ◽  
The Relationship

AbstractPostuma, F. A., and Gasalla, M. A. 2010. On the relationship between squid and the environment: artisanal jigging for Loligo plei at São Sebastião Island (24°S), southeastern Brazil. – ICES Journal of Marine Science, 67: 1353–1362. The squid Loligo plei concentrates in the southeastern Brazil Bight, where it has traditionally supported small-scale fisheries around São Sebastião Island (SSI). Sea surface temperature (SST), chlorophyll-a (Chl a), windspeed, wave height, rainfall, and lunar phase are related to fishing records and to the results of a survey of local fishers to investigate how they believe environmental variables might affect catches of L. plei. Daily fishery-dependent data over the years 2005–2009 were obtained from a fishing cooperative and were matched with satellite and meteorological forecast data. Generalized linear models were used to explore the significance of environmental variables in relation to variability in catch and catch per unit effort (cpue). Squid are fished with jigs in water shallower than 20 m, generally where SST is warmer and Chl a and windspeed are lower. Cpue and monthly catches decreased from 2005 to 2008, followed by a slight increase in 2009. The correlations between fishery and environmental data relate well to fishers' oceanological knowledge, underscoring the potential of incorporating such knowledge into evaluations of the fishery.

scholarly journals Experimental evaluation of influence of FADs on community structure and fisheries in coastal Kenya

2018 ◽  
Vol 31 ◽  
pp. 6 ◽  
Author(s):  
Emmanuel K. Mbaru ◽  
Dorcas Sigana ◽  
Renison K. Ruwa ◽  
Elizabeth M. Mueni ◽  
Collins K. Ndoro ◽  
...  
Keyword(s):  
Fish Assemblages ◽  
Small Scale ◽  
Catch Per Unit Effort ◽  
Fish Stocks ◽  
Coastal Fisheries ◽  
Small Scale Fisheries ◽  
Open Sea ◽  
Catch Composition ◽  
Structural Indices ◽  
Fish Aggregating Devices

Fish aggregating devices (FADs) have been widely used by commercial fisheries to increase the catchability of pelagic stocks in the open sea. FADs have the potential to enhance nearshore small-scale fisheries where stocks are often overfished. This study examined changes in catch composition, abundance, catch and effort, and aspects of diversity in Kenya's nearshore coastal fisheries after deployment of anchored fish aggregating devices (AFADs). The study combined both fishery independent and dependent methods in assessing changes in fish assemblages post-deployment. Results showed orders of magnitude increase in length, weight, commercial value, and catch per unit effort (CPUE) of landed catch after deployment of FADs suggesting that FADs had a positive effect on the local fishery. Species richness at FAD sites increased post-deployment (n = 281) compared to pre-deployment values (n = 223). Simultaneous use of several complementary structural indices may be required in order to accurately describe and monitor fish assemblages around the FADs. The findings suggest that AFADs are capable of creating both short and long-term impacts on livelihoods, with the potential to deflect pressure on the overfished nearshore fish stocks. However, more research will be needed on redistribution of fish around FADs, design and placement configuration, and site selection amongst others.

Does habitat or depth influence catch rates of pelagic species?

2007 ◽  
Vol 64 (11) ◽  
pp. 1581-1594 ◽  
Author(s):  
Keith A Bigelow ◽  
Mark N Maunder
Keyword(s):  
Relative Abundance ◽  
Environmental Conditions ◽  
Environmental Data ◽  
Catch Per Unit Effort ◽  
Blue Shark ◽  
Species Vulnerability ◽  
Thunnus Obesus ◽  
Catch Rates ◽  
The Relationship ◽  
The Vertical Distribution

The efficiency of a pelagic longline fishing operation and the species composition of the resulting catch is influenced primarily by the relationship between the distribution of hooks and species vulnerability, with vulnerability described by either depth or some suite of environmental variables. We therefore fitted longline catch rate models to determine whether catch is estimated better by vertically distributing a species by depth or by environmental conditions (e.g., temperature, thermocline gradient, and oxygen concentration). Catch rates were estimated by two methods: (i) monitoring longlines where the vertical distribution of hooks and catch in relation to depth and environmental conditions is known, and (ii) applying a statistical habitat-based standardization (statHBS) model to fishery and environmental data to develop relative abundance indices for bigeye tuna (Thunnus obesus) and blue shark (Prionace glauca). Results indicated that an understanding of gear dynamics and environmental influences are important for analyzing catch-per-unit-effort (CPUE) data correctly. Analyses based on depth-specific catch rates can lead to serious misinterpretation of abundance trends, despite the use of sophisticated statistical techniques (e.g., generalized linear mixed models). This illustrates that inappropriate inclusion or exclusion of important covariates can bias estimates of relative abundance, which may be a common occurrence in CPUE analysis.

scholarly journals Bony fishes (Teleostei) caught by small-scale fisheries off central to south coast of São Paulo State, Southeastern Brazil

2014 ◽  
Vol 14 (4) ◽  
Author(s):  
Fabio Santos Motta ◽  
Marcos Rogério Rosa ◽  
Rafael Cabrera Namora ◽  
Otto Bismarck Fazzano Gadig
Keyword(s):  
Conservation Status ◽  
Abundant Species ◽  
Sao Paulo ◽  
Southeastern Brazil ◽  
Species Number ◽  
Small Scale ◽  
Artisanal Fisheries ◽  
São Paulo ◽  
Small Scale Fisheries ◽  
Bony Fishes

Small-scale fisheries have a great socioeconomic importance in Brazil. Different regional characteristics along the coast, mostly related to landing sites, equipment used, and targeted species, renders its assessment and monitoring difficult. The aim of this paper is to present a list of species of bony fishes (Teleostei) caught by artisanal fisheries along the São Paulo coast, southeastern Brazil and to provide comments on the relative abundance and conservation status of those species. A total of 315 fishing fleet landings were surveyed, and 106 species distributed among 38 families were recorded. Sciaenidae and Carangidae were the most frequent families in species number. The southern king weakfish, Macrodon atricauda, was the most abundant species, representing 28.03% of the total number of specimens caught. Eleven of the most abundant species are classified as Overexploited in the country or as Near Threatened in the state of São Paulo. These findings reinforce the relevance of assessing and managing artisanal fisheries.

scholarly journals MORPHOMETRICS OF JUVENILE WHITE SHRIMP IN SANTOS (SP, BRAZIL) - AN ATLANTIC STRESSED ESTUARY

2020 ◽  
Vol 46 (3) ◽  
pp. 1-6
Author(s):  
Felippe Veneziani ABBATEPAULO ◽  
◽  
Sergio Luiz dos Santos TUTUI ◽  
Acacio Ribeiro Gomes TOMÁS ◽  
◽  
...  
Keyword(s):  
White Shrimp ◽  
Small Scale ◽  
Body Measurement ◽  
Recreational Fisheries ◽  
Southwest Atlantic ◽  
Small Scale Fisheries ◽  
Total Length ◽  
Males And Females ◽  
Live Bait ◽  
The Relationship

Shrimps are one of the world’s most valuable fishing resources, with the Penaeidae family having the greatest economic importance. In the southwest Atlantic the white shrimp Litopenaeus schmitti plays an important socioeconomic role for small-scale fisheries, and juveniles are targeted as live bait for recreational fisheries. This study was carried out monthly along two periods (May/2009‑January/2010 and March/2011-March/2015) at Santos estuary and aimed to investigate the relationship between morphometric and sex of the early development stages of Litopenaeus schmitti. A total of 6,978 individuals were caught and measured, with no differences (p>0.1) between sexes shown regarding total length or weight. Differences between males and females were found for Total length (TL) x Carapace length (CL) and TL x Total weight (TW) and negative allometries (b<3) were found for all relationships. The results indicate that morphometric differences among sexes seem to be more associated with total length, suggesting that TL could be a more appropriate body measurement to compare specimens of L. schmitti, at least when the analysis includes juveniles. The presence of L. schmitti specimens all year long inside the estuary reinforces the idea of a continuous reproductive cycle with peak periods. Both information comes to fulfill part of the lack of knowledge regarding this species estuarine phases.

scholarly journals Focused small-scale fisheries as complex systems using deep learning models

2021 ◽  
Vol 49 (2) ◽  
pp. 342-353
Author(s):  
Ricardo Cavieses-Núñez ◽  
Miguel A. Ojeda-Ruiz ◽  
Alfredo Flores-Irigollen ◽  
Elvia Marín-Monroy ◽  
Mirtha Lbañez-Lucero ◽  
...  
Keyword(s):  
Deep Learning ◽  
Environmental Variables ◽  
Predictive Power ◽  
Small Scale ◽  
Learning Models ◽  
Small Scale Fisheries ◽  
Productive Activities ◽  
Lack Of Information ◽  
Management Measures ◽  
The Face

Small-scale fishing (SSF) is a relevant economic activity worldwide, so sustainable development will be essential to assure its contributions to food security, poverty alleviation, and healthy ecosystems. However, the wide diversity of fisheries, their complexity, and the lack of information limit the ability to propose/evaluate management measures and plans and their effects on communities and other productive activities. The state of Baja California Sur, Mexico, our study case, ranks as the third place in national fisheries production, possesses SSF fleets, has a wide variety of fisheries that share fishing areas, fishing seasons, and operating units. In this work, assuming SSF as a complex system were proposed deep learning models (DLM) to forecast the catch volumes, evaluate each input variable's importance, and find interactions. Environmental variables and catch fisheries were tested in the DLM to estimate their predictive power. Different DLM structures and parameters to find the optimal model was used. The variables that presented higher predictive power are the environmental variables with R = 0.90. Moreover, when used in combination with the catches from other areas, the performance of R = 0.95 is obtained. Using only the catches, the model has an R = 0.81. This model allows the use of variables that indirectly affect the system and demonstrates a useful tool to assess a complex system's state in the face of disturbances in its variables.

scholarly journals OVERFISHING AND OVERCAPACITY SMALL SCALE FISHERIES IN SEMARANG CITY

2019 ◽  
Vol 11 (2) ◽  
pp. 427-435
Author(s):  
Jamaludin Malik ◽  
Achmad Fahrudin ◽  
Dietriech Geoffrey Bengen ◽  
Taryono Khodiron
Keyword(s):  
Sustainable Management ◽  
Maximum Sustainable Yield ◽  
Utilization Rate ◽  
Small Scale ◽  
Fishing Gear ◽  
Catch Per Unit Effort ◽  
Small Scale Fisheries ◽  
Surplus Production ◽  
Capacity Level ◽  
The Status

Fisheries in Semarang City are dominated by small-scale fisheries. This is indicated by the use of the largest fishing fleet of 10 gross tons operating near the coast. This study aims to analyze the status of small-scale fisheries in Semarang City for sustainable management. Sustainable management is management that guarantees the availability of natural resources and environmental services for future generations. The study was conducted for three months, namely September-November 2018 in the coastal waters of Semarang City, which was part of the Fisheries Management Region (WPP) 712. The method used in this study is the analysis of time series surplus production, namely data from the catch (ton/year) and the number of fishing gear (unit) within 10 years (2007-2016), to calculate the catch per-unit effort (CPUE), maximum sustainable yield (MSY), optimum effort (fopt), utilization rate (TP) and capacity level (TK). This study was obtained results of a downward trend in CPUE; the existing fishery catch or production in 2016 has exceeded the MSY value is 479 tons/year (Schaefer) and 439.11 tons/year (Fox); utilization rate of more than 100% which is 108-127% (Schaefer) and 118-138% (Fox), so that small-scale fisheries in Semarang City are at the level of over-exploited. Based on the fopt analysis, the number of fishing gear used (fexisting) has exceeded the optimum effort with a fishing capacity exceeding 100%, so that small-scale fisheries in Semarang City have experienced overcapacity.

scholarly journals Fishing Effort and Associated Catch per Unit Effort for Small-Scale Fisheries in the Mozambique Channel Region: 1950–2016

2021 ◽  
Vol 8 ◽  
Author(s):  
Dirk Zeller ◽  
Gabriel M. S. Vianna ◽  
Matthew Ansell ◽  
Angie Coulter ◽  
Brittany Derrick ◽  
...  
Keyword(s):  
Fishing Effort ◽  
Small Scale ◽  
Catch Per Unit Effort ◽  
Important Species ◽  
Small Scale Fisheries ◽  
Mozambique Channel ◽  
Fishing Vessels ◽  
Unit Effort ◽  
Fishing Capacity ◽  
Channel Region

The Mozambique Channel region in East Africa has diverse marine ecosystems and serves as a migratory corridor for economically important species. Local and foreign industrial fisheries operate in the Mozambique Channel, but regional small-scale fisheries are the crucially important fisheries that provide food security, livelihoods, and economic opportunities for rural coastal communities. This study reconstructed and investigated trends in the fishing effort and catch per unit effort (CPUE) of small-scale marine fisheries in four Exclusive Economic Zones (EEZ) that constitute the Mozambique Channel, i.e., Union of Comoros, Madagascar, Mayotte, and Mozambique, from 1950 to 2016. Effective fishing effort for small-scale fisheries in the form of fishing capacity in kWdays (i.e., kilowatt days) was derived using the number, length, motorization (engine power) by fishing vessels, as well as an approximate human-powered equivalent for shore-based fishers without vessels, as well as days of fishing per year. Effective small-scale fishing effort in the Mozambique Channel increased by nearly 60 times from just over 386,000 kWdays in 1950 to over 23 million kWdays in 2016. Correspondingly, the overall small-scale CPUE, based on previously and independently reconstructed catch data declined by 91% in the region as a whole, from just under 175 kg⋅kWday–1 in the early 1950s to just over 15 kg⋅kWday–1 in recent years. All four EEZs showed the strongest declines in the small-scale CPUE in the earlier decades, driven by motorization and growth in vessel numbers impacting effective fishing effort. Increased motorization combined with a substantial growth in overall vessel numbers were the drivers of the increasing fishing effort and decreasing CPUE, and clearly suggest that continuing to increase the fishing capacity of small-scale fisheries in the absence of effective and restrictive management actions may exacerbate overexploitation risk.

scholarly journals Establishing a governance threshold in small-scale fisheries to achieve sustainability

AMBIO ◽  
2021 ◽  
Author(s):  
Alba Aguión ◽  
Elena Ojea ◽  
Lucía García-Flórez ◽  
Teresa Cruz ◽  
Joxe Mikel Garmendia ◽  
...  
Keyword(s):  
Social Economic ◽  
Spatial Scales ◽  
Small Scale ◽  
Effective Governance ◽  
Small Scale Fisheries ◽  
Pollicipes Pollicipes ◽  
Mere Presence ◽  
Monitoring And Surveillance ◽  
Access Rights ◽  
The Relationship

AbstractThe lack of effective governance is a major concern in small-scale fisheries. The implementation of governance that encompasses the three pillars of sustainability (social, economic, and ecological) is still a worldwide challenge. We examined nine stalked barnacle fisheries (Pollicipes pollicipes) across Southwest Europe to better understand the relationship between governance elements and sustainability. Our results show that nested spatial scales of management, the access structure, co-management, and fisher’s participation in monitoring and surveillance promote sustainability. However, it is not the mere presence of these elements but their level of implementation that drives sustainability. Efforts should be placed in the accomplishment of a minimum combination of local scales of management, access rights through individual quotas, instructive-consultative co-management and functional participation. Surpassing this threshold in future governance structures will start to adequately promote social, economic and ecologically sustainability in small-scale fisheries.

scholarly journals Small-scale fisheries in Madeira: recreational vs artisanal fisheries

2021 ◽  
Vol 85 (4) ◽  
pp. 257-270
Author(s):  
Roi Martínez-Escauriaza ◽  
Francesca Gizzi ◽  
Lídia Gouveia ◽  
Nuno Gouveia ◽  
Margarida Hermida
Keyword(s):  
Coastal Ecosystems ◽  
Small Scale ◽  
Artisanal Fisheries ◽  
Artisanal Fishery ◽  
Catch Per Unit Effort ◽  
Small Scale Fisheries ◽  
Recreational Fishery ◽  
Management Of Resources ◽  
Pagrus Pagrus ◽  
Phycis Phycis

Small-scale recreational and artisanal fisheries are popular activities in the Autonomous Region of Madeira, and to date no information is available on their impact on regional coastal ecosystems. Through fishers’ surveys and official registers of fish landings, we described and characterized these fisheries in Madeira, comparing artisanal and recreational fisheries. In 2017, artisanal boats landed 91 species in fishing ports, while recreational catches landed 58 species. The most frequent catches were Dentex gibbosus, Phycis phycis and Pagrus pagrus for artisanal fishery and P. pagrus, Serranus atricauda and Diplodus spp. for recreational fishery. Comparing the same techniques, artisanal fishery always showed higher catch per unit effort values than recreational boat fishery. Nevertheless, the low number of artisanal fishery boats in comparison with the recreational ones reflected the lower total landings of the artisanal fishery, which in 2017 were 62.3 t, compared with the 509.8 t estimated catches for the recreational fishery. Though the estimated recreational fishing data were based on surveys and thus subject to various biases, this activity seems to negatively affect coastal ecosystems and, together with artisanal fishing, exerts a combined pressure on targeted species. Improved legislation for both fisheries is essential for an appropriate management of resources.

scholarly journals SEASONAL AND SPATIAL DYNAMIC OF SMALL SCALE FISHERIES IN CENTRAL AMAZONIA

2021 ◽  
Vol 6 (15) ◽  
pp. 206-223
Author(s):  
Vinícius Verona Carvalho Gonçalves ◽  
Jamerson Aguiar Dos Santos ◽  
Carlos Edwar de Carvalho Freitas
Keyword(s):  
Local Population ◽  
Principal Component ◽  
High Water ◽  
Small Scale ◽  
Catch Per Unit Effort ◽  
Fishing Activity ◽  
Small Scale Fisheries ◽  
Central Amazonia ◽  
Flood Period

Amazonia is considered to host some of the more productive freshwater fisheries of the world, and these are of key importance to the local population. Accordingly, fishing activity needs to be studied to evaluate its dynamics, so that long-term sustainability of the resource can be assured the fishing. The objective of the current study, therefore, was to analyze seasonal and spatial variation in the production of fish landed in the city of Manacapuru, in Central Amazonia. The landing data was collected daily from January to December 2012 at the main port of landing in Manacapuru, Amazonas, Brazil. Results indicate that lakes were most frequently visited by fishermen, but that rivers had higher catch values. In total, 39 species of fish were landed, with jaraqui escama grossa (Semaprochilodus taenirus) and jaraqui escama fina (Semaprochilodus insignis) being the species most exploited by fishermen. Landing had a seasonal character, with higher values in the rising and high water periods. Significant differences were observed between the different seasonal periods, with peak-flood period having the highest catch per unit effort (CPUE) values. Principal Component Analysis (PCA) revealed that fishing gear varied according to the fishing environment and exploited species.

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