scholarly journals Supporting Spatial Management of Data-Poor, Small-Scale Fisheries With a Bayesian Approach

2021 ◽  
Vol 8 ◽  
Author(s):  
Jennifer Rehren ◽  
Maria Grazia Pennino ◽  
Marta Coll ◽  
Narriman Jiddawi ◽  
Christopher Muhando
Keyword(s):  
Spatial Distribution ◽  
Marine Conservation ◽  
Environmental Drivers ◽  
Small Scale ◽  
Target Species ◽  
Short Term ◽  
Conservation Areas ◽  
Bayesian Hierarchical ◽  
Small Scale Fisheries ◽  
Spatial Management

Marine conservation areas are an important tool for the sustainable management of multispecies, small-scale fisheries. Effective spatial management requires a proper understanding of the spatial distribution of target species and the identification of its environmental drivers. Small-scale fisheries, however, often face scarcity and low-quality of data. In these situations, approaches for the prioritization of conservation areas need to deal with scattered, biased, and short-term information and ideally should quantify data- and model-specific uncertainties for a better understanding of the risks related to management interventions. We used a Bayesian hierarchical species distribution modeling approach on annual landing data of the heavily exploited, small-scale, and data-poor fishery of Chwaka Bay (Zanzibar) in the Western Indian Ocean to understand the distribution of the key target species and identify potential areas for conservation. Few commonalities were found in the set of important habitat and environmental drivers among species, but temperature, depth, and seagrass cover affected the spatial distribution of three of the six analyzed species. A comparison of our results with information from ecological studies suggests that our approach predicts the distribution of the analyzed species reasonably well. Furthermore, the two main common areas of high relative abundance identified in our study have been previously suggested by the local fisher as important areas for spatial conservation. By using short-term, catch per unit of effort data in a Bayesian hierarchical framework, we quantify the associated uncertainties while accounting for spatial dependencies. More importantly, the use of accessible and interpretable tools, such as the here created spatial maps, can frame a better understanding of spatio-temporal management for local fishers. Our approach, thus, supports the operability of spatial management in small-scale fisheries suffering from a general lack of long-term fisheries information and fisheries independent data.

scholarly journals Characterization of small-scale fisheries in the Camamu-Almada basin, southeast state of Bahia, Brazil

2008 ◽  
Vol 68 (4) ◽  
pp. 711-719 ◽  
Author(s):  
TCM. Souza ◽  
M. Petrere-Jr
Keyword(s):  
Low Income ◽  
Small Scale ◽  
Income Generation ◽  
Target Species ◽  
Market Prices ◽  
Marine Fishery ◽  
Small Scale Fisheries ◽  
Main Factor ◽  
Stock Abundance

In the Camamu-Almada basin, marine fishery is exclusively small-scale, with several structural deficiencies such as boats with low or absent navigational technology, lack of credit and low income. Local fishers complain that shrimp and lobster trawling fishing is the main factor responsible for low stock abundance, but they still persist in these activities as these two species command the highest market prices. So they feel that the target species are already over-fished. We suggest that proper management action, alternative ways of income generation and the payment of job insurance would help to mitigate the problem.

scholarly journals Designing locally-appropriate conservation incentives for small-scale fishers

2021 ◽  
Author(s):  
Hollie Booth ◽  
M Said Ramdlan ◽  
Ayesha Hafizh ◽  
Karto Wongsopatty ◽  
Susana Mourato ◽  
...  
Keyword(s):  
Cost Effective ◽  
Marine Conservation ◽  
Small Scale ◽  
Marine Animals ◽  
Small Scale Fisheries ◽  
Outcome Goals ◽  
Use Values ◽  
Combination Of Methods ◽  
Marine Megafauna ◽  
Business As Usual

Large, long-lived marine animals (‘marine megafauna’) play critical roles in ocean ecosystems, however, they are threatened by overfishing. Technologies and practices that reduce fisheries’ impacts on marine megafauna are well documented, yet less is known about how to encourage their adoption. This is particularly challenging in small-scale fisheries (SSFs), where endangered species can have important consumptive use values. We used a novel combination of methods – scenario interviews with contingent valuation (CV) – to investigate how incentive-based interventions might influence fisher behaviour and reduce mortality of Critically Endangered taxa (hammerhead sharks (Sphyrna spp.) and wedgefish (Rhynchobatus spp.)) in two case study SSFs in Indonesia. Scenario interviews revealed that positive performance-based incentives were almost unanimously supported (98% and 96% of fishers would stop landing hammerheads and wedgefish, respectively). This is in contrast to 1% and 6% under a business as usual control scenario, and 52% and 46% in response to a regulation with a fine. Using CV, we estimated that an incentive-based scheme for catch mitigation of all hammerheads and wedgefish across both sites could cost US$71,620-298,820 annually, and save up to 18,500 hammerheads and 2,140 wedgefish relative to current catch baselines. This study provides empirical evidence that performance-based payments could offer a cost-effective, legitimate and socially-just approach for marine conservation in SSFs, and support “a sustainable and equitable blue economy” and “living in harmony with nature”. This is particularly important with the growing adoption of net-outcome goals for biodiversity, with studies such as this providing the basis for locally-appropriate investment ready schemes for bycatch-neutral seafood supply chains.

scholarly journals Net Fisheries’ Métiers in the Eastern Mediterranean: Insights for Small-Scale Fishery Management on Kalymnos Island

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1509 ◽  
Author(s):  
Kyriakoula Roditi ◽  
Dimitris Vafidis
Keyword(s):  
Mediterranean Sea ◽  
Fishery Management ◽  
Eastern Mediterranean ◽  
Market Price ◽  
Aegean Sea ◽  
Small Scale ◽  
Target Species ◽  
Essential Information ◽  
Small Scale Fisheries ◽  
The Difference

Small-scale fisheries constitute an important component of coastal human societies. The present study describes the small-scale net fisheries on Kalymnos Island (south-east Aegean Sea) that harbors the largest small-scale fleet in the eastern Mediterranean Sea. In addition, this study aims to evaluate their characteristics and economics. Relevant métiers were identified through a multivariate analysis by inputting the main resources and fishing gear data that were recorded during landings. Four main practices were observed being used as fishing gears, gillnets and trammel nets, targeting the species Mullus barbatus, Boops boops, Mullus surmuletus, Scorpaena porcus, and Sepia officinalis. Further analysis, which incorporated data concerning the type of the gear used, revealed 11 distinct métiers. Most of these métiers are practiced by other Mediterranean small-scale fisheries as well, in terms of target species, gear and seasonality. However, the métier that had its target species as B.boops is not practiced in other Mediterranean small-scale fisheries. The seasonal rotation of métiers was determined by the availability of different species rather than their market price. The results revealed the difference in fishing practice used by the fishermen in the study area compared to other fishing practices in the Mediterranean Sea. In particular, the fishermen of this study area targeted more species (B.boops) with a very low market price. They also provided essential information for the development and implementation of management plans aiming at the sustainability of small-scale fisheries.

scholarly journals Effect of temporal and spatial resolution on identification of fishing activities in small-scale fisheries using pots and traps

2019 ◽  
Vol 76 (6) ◽  
pp. 1601-1609 ◽  
Author(s):  
Tania Mendo ◽  
Sophie Smout ◽  
Tommaso Russo ◽  
Lorenzo D’Andrea ◽  
Mark James
Keyword(s):  
Spatial Distribution ◽  
Spatial Resolution ◽  
Large Scale ◽  
Low Cost ◽  
Grid Cell ◽  
Analysis Data ◽  
Satellite System ◽  
Small Scale ◽  
Fishing Activity ◽  
Small Scale Fisheries

Abstract Analysis of data from vessel monitoring systems and automated identification systems in large-scale fisheries is used to describe the spatial distribution of effort, impact on habitats, and location of fishing grounds. To identify when and where fishing activities occur, analysis needs to take account of different fishing practices in different fleets. Small-scale fisheries (SSFs) vessels have generally been exempted from positional reporting requirements, but recent developments of compact low-cost systems offer the potential to monitor them effectively. To characterize the spatial distribution of fishing activities in SSFs, positions should be collected with sufficient frequency to allow detection of different fishing behaviours, while minimizing demands for data transmission, storage, and analysis. This study sought to suggest optimal rates of data collection to characterize fishing activities at appropriate spatial resolution. In a SSF case study, on-board observers collected Global Navigation Satellite System (GNSS) position and fishing activity every second during each trip. In analysis, data were re-sampled to lower temporal resolutions to evaluate the effect on the identification of number of hauls and area fished. The effect of estimation at different spatial resolutions was also explored. Consistent results were found for polling intervals <60 s in small vessels and <120 in medium and large vessels. Grid cell size of 100 × 100 m resulted in best estimations of area fished. Remote collection and analysis of GNSS or equivalent data at low cost and sufficient resolution to infer small-scale fisheries activities. This has significant implications globally for sustainable management of these fisheries, many of which are currently unregulated.

scholarly journals Seasonal dynamics of small-scale fisheries in the Adriatic Sea

2018 ◽  
Vol 19 (1) ◽  
pp. 21 ◽  
Author(s):  
FABIO GRATI ◽  
ADMIR ALADZUZ ◽  
ERNESTO AZZURRO ◽  
LUCA BOLOGNINI ◽  
PIERLUIGI CARBONARA ◽  
...  
Keyword(s):  
Seasonal Dynamics ◽  
Adriatic Sea ◽  
Economic Value ◽  
Fishing Effort ◽  
Small Scale ◽  
Target Species ◽  
Frequency Distributions ◽  
Small Scale Fisheries ◽  
Blue Growth ◽  
Physical And Chemical

The main aim of the present study is to increase the knowledge on the seasonal dynamics of the set gears used by Adriatic small-scale fisheries (SSFs) through the collation of data (landings, fishing effort, composition of catches, length-frequency distributions of target species and economic value of landings) on target species,. The study focused on the three set gears mainly used in the basin: gillnets, trammel nets and traps. The results confirmed that SSFs are diverse, complex and dynamic, representing an economic and social engine and providing seafood and employment to local economies. In the Adriatic Sea, SSFs exploit coastal fishing grounds where the seasonal fluctuations of the physical and chemical parameters of the water column strongly influence the occurrence of the different species. Because of this, many different types of set gears are currently used to catch a pool of target species over the year. Fishermen use more than one set gear during the year and tend to increase the fishing effort when the target species concentrate inside the coastal areas during the recruitment or the spawning season. Accordingly, landings reached the highest values during such periods and often include a large portion of juveniles and/or spawners. The study highlighted that the lack of appropriate data and complete statistics is still one of the main constraints for most of the Adriatic coastal countries, as few countries have in place routinely monitoring programs while others are dealing mostly with estimates. These gaps often have the effect of marginalizing and undervaluing the real role of SSFs in a Blue Growth process.

scholarly journals Catch, bycatch and discards of the Galapagos Marine Reserve small-scale handline fishery

2015 ◽  
Author(s):  
Johanna S Zimmerhackel ◽  
Anna C Schuhbauer ◽  
Paolo Usseglio ◽  
Lena C Heel ◽  
Pelayo Salinas-de-León
Keyword(s):  
Marine Reserve ◽  
Marine Conservation ◽  
Economic Consequences ◽  
Small Scale ◽  
Local Market ◽  
Target Species ◽  
Fisheries Bycatch ◽  
Spatio Temporal ◽  
Catch Composition ◽  
Galapagos Marine Reserve

Fisheries bycatch is one of the most significant marine conservation issues as valuable fish are wasted and protected species harmed with potential negative ecological and socio-economic consequences. Even though there are indications that the small-scale handline fishery of the Galapagos Marine Reserve has a low selectivity, information on its bycatch never has been published. We therefore assessed the bycatch of the Galapagos handline fishery by estimating the bycatch ratio, determining species compositions of landings and bycatch, and identifying fishers’ reasons for discarding certain individuals using onboard monitoring and interview data. Moreover, we used interview surveys to reveal historical trends in the bycatch ratio. The estimated bycatch ratio of 0.40 confirmed a low selectivity of this fishery. Characterisation of the catch resulted in a total of 19 target species which were dominated by groupers, and 53 non-target species, with grunts and groupers being most prominent. Most individuals were not landed for economic motivations, either because species (77.4%) or sizes (17.7%) are not marketable and to a lesser extent for regulatory reasons (5.9%). However, sharks were after grunts with 69% the second most often mentioned bycatch taxa during interview surveys. We found that small sized individuals of some of the most exploited species suffer high bycatch mortality because they are used as bait. Moreover, over half of interviewees perceived a historical decrease in bycatch ratios that was explained by a diversification of the catch composition due to the reduction in abundance of the traditionally most important target species. As some target species show signs of overfishing and to date there are no specific regulations for the finfish fishery in place, we recommend the investigation of different gear settings such as the use of different hooks and bait species. Furthermore, we suggest the integration of faster growing species to the local market as well as spatio-temporal closures, and minimum and maximum catch sizes for overexploited species in order to improve the selectivity and sustainability of the Galapagos handline fishery.

Perceptions of gender dynamics in small‐scale fisheries and conservation areas in the Pursat province of Tonle Sap Lake, Cambodia

2020 ◽  
Vol 61 (1) ◽  
pp. 54-70 ◽  
Author(s):  
Y.K. Eugenia Kwok ◽  
Krishna Bahadur KC ◽  
Jennifer J. Silver ◽  
Evan Fraser
Keyword(s):  
Small Scale ◽  
Conservation Areas ◽  
Gender Dynamics ◽  
Small Scale Fisheries ◽  
Tonle Sap Lake ◽  
Tonle Sap

scholarly journals Structure and spatio-temporal dynamics of the artisanal small-scale fisheries at the future MPA of “Taza” (Algerian coast, SW Mediterranean)

2018 ◽  
Vol 19 (3) ◽  
pp. 555 ◽  
Author(s):  
IBRAHIM BOUBEKRI ◽  
ALEX JAMES CAVEEN ◽  
ABDALLAH BORHANE DJEBAR ◽  
RACHID AMARA ◽  
HUBERT MAZUREK
Keyword(s):  
Temporal Dynamics ◽  
Field Work ◽  
Management Plan ◽  
Small Scale ◽  
Target Species ◽  
Small Scale Fisheries ◽  
The Future ◽  
Mullus Surmuletus ◽  
Spatio Temporal ◽  
Management Approaches

Artisanal Small-Scale Fisheries (SSFs) are a primordial and very diverse activity in the Mediterranean, also within Marine Protected Areas (MPAs). This diversity is explained in terms of target species, gears, and fishing strategies. The main objective of this work was to investigate the spatio-temporal dynamics of artisanal SSFs of the future MPA of “Taza” (Algeria, SW Mediterranean). Data were collected through direct assessment of daily landings and using questionnaires. They were the subject of multivariate analyses that allowed us to identify the métiers practiced by artisanal fishers. During the one year (May 2013 to April 2014) field work period, 1330 fishing trips and 1613 fishing operations in 16 fishing grounds were recorded in the Ziama fishing harbor, where 15.2 tons of total catch was assessed. Our results show that, in the study area, the boats are predominantly gillnetters and that among the five métiers characterized by target species, gear type, fishing grounds, and fishing seasons, two métiers (“Mullus surmuletus trammel net” and “Sparids monofilament gillnet”) are practiced throughout the year, while the remaining three (“Sarda sarda driftnet”, “Merluccius merluccius set gillnet”, and “Pagellus set gillnet”) are specific to a determined period of the year. The ‘Mullus surmuletus trammel net’ métier represents 40% of the total fishing operations, of which 57.5% are carried out in the coastal sector at - 25 m. This study could contribute to defining the appropriate management approaches for SSFs in the future MPA of “Taza” by providing baseline information to build a sound management plan. In Algeria, it will certainly serve as a scientific reference in terms of zoning, protection of biodiversity, and specific monitoring at particular locations and periods of the year for the sustainable management of MPAs.

scholarly journals Small scale fisheries performance: comparative analysis before and during the Covid-19 pandemic in Indonesia

2021 ◽  
Vol 322 ◽  
pp. 05001
Author(s):  
Alimudin Laapo ◽  
Dietriech G. Bengen ◽  
Kamsina ◽  
Taryono Kodiran ◽  
Dafina Howara
Keyword(s):  
High Performance ◽  
Comparison Method ◽  
The Other ◽  
Small Scale ◽  
Beach Seine ◽  
Short Term ◽  
Small Scale Fisheries ◽  
Fish Catch ◽  
Economic Contribution ◽  
Central Sulawesi

The incidence of the Covid-19 pandemic indirectly affects the decline in the activity of the processing industry and fish consumption by the community. In the short term, there is also a decline in fish prices. This study examines whether the decline in economic activity in the fisheries sector causes changes in the performance of small-scale fisheries, both before and during the Covid-19 pandemic in Tolitoli Regency, Central Sulawesi Province. The target of the research object is fishers who use trolling lines, handline, and beach seine. The analytical method used is Exponential Comparison Method. The results showed that capture fisheries belonging to SSF, which had high performance before covid-19, were fishing gear, and the lowest performance was Surrounding net. On the other hand, the surrounding net has a higher performance during the pandemic than the other three fishing gears, and the lowest is Trolling lines. However, there has been a significant decline in prices and market affordability, the economic contribution of small-scale fishing businesses from before and during the COVID-19 pandemic. For this reason, a policy to open up an export-oriented fish catch market and a wider market reach is required.

scholarly journals Tasa de captura y composición de tamaños de Anadara spp. en Puerto El Morro, Ecuador

2018 ◽  
pp. 01
Author(s):  
Luis Alfredo Flores Vera ◽  
Maribel Morales-Escalante
Keyword(s):  
Spatial Distribution ◽  
Size Composition ◽  
Fishing Effort ◽  
Catch Rate ◽  
Biological Information ◽  
Small Scale ◽  
Population Status ◽  
Short Term ◽  
Palabras Clave ◽  
Mean Size

Catch rate and size composition of mangrove cockles Anadara spp. in Puerto El Morro, Ecuador Resumen Un análisis de la tasa de captura [captura por unidad de esfuerzo (CPUE)] y la composición de tamaños del desembarque de concha en la localidad de Puerto El Morro, fue realizado entre los años 2011 y 2013 a partir de información colectada en base a una bitácora de pesca. La CPUE promedio para el año 2011 fue de 115 conchas.conchero-1.día-pesca-1, mientras que para el 2012 y 2013 fue de 122 y 126 conchas.conchero-1.día-pesca-1, respectivamente. La captura estuvo compuesta principalmente por la especie A. tuberculosa en los tres años (>99 %). La longitud promedio de captura para A. tuberculosa oscilo entre 48,8 mm y 49,2 mm para el periodo de estudio. Un bajo porcentaje de tallas no comerciales caracterizó la pesquería del recurso. Se infiere un ligero incremento en la CPUE entre el 2011 y 2013, provocado quizás por la reducción observada en la población operativa de concheros y la distribución espacial del esfuerzo de pesca a zonas de mayor productividad. Se sugiere a corto plazo la evaluación directa de las principales áreas de pesca para conocer el estado actual de las mismas y relacionarla con indicadores pesqueros. Palabras clave: captura por unidad de esfuerzo (cpue); estructura poblacional; pesquería artesanal; recurso concha; Refugio de Vida Silvestre Manglares El Morro. Abstract Catch rate [catch per unit of effort (CPUE)] and size composition of the mangrove cockle fishery were analyzed in Puerto El Morro from 2011 to 2013 based on a fishing logbook to register the fishery and biological information. The average CPUE in 2011 was 115 cockles.cockle-collector-1.fishing-day-1, whereas 122 cockles.cockle-collector-1.fishing-day-1 for 2012 and 126 cockles.cockle-collector-1.fishing-day-1 for 2013. A high percentage of the specie A. tuberculosa was observed in the catch in all years (>99%). It was estimated for A. tuberculosa a mean size between 48,8 mm and 49,2 mm. Also, a low percentage of non-commercial sizes were observed in the catch. The slight increase of the CPUE between 2011 and 2013 is perhaps a result of the reduction in fishing effort and its spatial distribution to fishing areas of higher yield. It is suggested in a short term to assess the most important fishing areas to know the population status of this, and related to indicators of the fishery. Keywords: catch per unit of effort (CPUE); population structure; small-scale fishery; mangrove cockle; Refugio de Vida Silvestre Manglares El Morro.

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