scholarly journals Using pingers to reduce bycatch of small cetaceans in Peru's small-scale driftnet fishery

Oryx ◽  
2013 ◽  
Vol 47 (4) ◽  
pp. 595-606 ◽  
Author(s):  
Jeffrey C. Mangel ◽  
Joanna Alfaro-Shigueto ◽  
Matthew J. Witt ◽  
David J. Hodgson ◽  
Brendan J. Godley

AbstractThere is growing awareness that small-scale fisheries may have large impacts on threatened marine fauna. Bycatch of small cetaceans by the Peruvian small-scale driftnet fleet results in the deaths of thousands of animals annually. We sought to assess the effectiveness of acoustic alarms (pingers) for reducing the incidental capture of dolphins and porpoises by this fleet. Forty-three experimental trips (156 fishing sets) and 47 control trips (195 fishing sets) out of Salaverry Port, northern Peru, were observed from April 2009 to August 2011. Twenty-two percent of control sets captured small cetaceans (67 individuals) and 16% of experimental sets had captures of small cetaceans (33 individuals). The bycatch rate of experimental sets was 0.50 individuals km−2h−1, whereas for control sets the rate was 0.80 individuals km−2h−1. This 37% reduction in bycatch rate suggests that pingers may be effective in reducing the bycatch of small cetaceans in this fishery. Catch rates of the fishery's target shark and ray species were unchanged. Given the vast size of this fishery and its current levels of bycatch of small cetaceans (> 10,000 individuals annually), even the modest declines in bycatch we observed could result in reductions in mortality of hundreds or thousands of small cetaceans per annum. Challenges, including increased costs, to large-scale utilization of pingers have yet to be overcome. The harpooning of dolphins for use as bait will also need to be addressed for further reductions in dolphin and porpoise bycatch and mortality to be achievable.

1973 ◽  
Vol 30 (12) ◽  
pp. 2172-2177
Author(s):  
P. C. George

Small-scale fisheries have traditionally been the backbone of the fishing industry all over the world. Although large-scale mechanized fishing has come into the limelight recently, even such countries as have developed substantial capability in this direction still have a large fleet of small boats in coastal areas. The landings of this sector of the industry are always substantial, and in many countries they still dominate the picture. In India, small-scale fisheries landed almost 1.15 million tons in 1971. This figure has been increasing as motor-powered small craft have increased in numbers, although 70% of marine fish is still caught from nonpowered boats. Measures taken to increase fishing capacity, landings, and net fishermen’s income over the past 10 years include various kinds of loans and subsidies for the purchase of boats, motors, and nets; assistance for the construction of ponds in inland areas; organization of cooperatives; training programs for fishermen and supporting personnel, especially motor repairmen (with the cooperation of Norway); and gear and vessel research including pilot-scale demonstrations with new types of vessels and equipment.


PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0234760
Author(s):  
Alexander Tilley ◽  
Joctan Dos Reis Lopes ◽  
Shaun P. Wilkinson

Small-scale fisheries are responsible for landing half of the world’s fish catch, yet there are very sparse data on these fishing activities and associated fisheries production in time and space. Fisheries-dependent data underpin scientific guidance of management and conservation of fisheries systems, but it is inherently difficult to generate robust and comprehensive data for small-scale fisheries, particularly given their dispersed and diverse nature. In tackling this challenge, we use open source software components including the Shiny R package to build PeskAAS; an adaptable and scalable digital application that enables the collation, classification, analysis and visualisation of small-scale fisheries catch and effort data. We piloted and refined this system in Timor-Leste; a small island developing nation. The features that make PeskAAS fit for purpose are that it is: (i) fully open-source and free to use (ii) component-based, flexible and able to integrate vessel tracking data with catch records; (iii) able to perform spatial and temporal filtering of fishing productivity by fishing method and habitat; (iv) integrated with species-specific length-weight parameters from FishBase; (v) controlled through a click-button dashboard, that was co-designed with fisheries scientists and government managers, that enables easy to read data summaries and interpretation of context-specific fisheries data. With limited training and code adaptation, the PeskAAS workflow has been used as a framework on which to build and adapt systematic, standardised data collection for small-scale fisheries in other contexts. Automated analytics of these data can provide fishers, managers and researchers with insights into a fisher’s experience of fishing efforts, fisheries status, catch rates, economic efficiency and geographic preferences and limits that can potentially guide management and livelihood investments.


Environments ◽  
2020 ◽  
Vol 7 (12) ◽  
pp. 104
Author(s):  
Cristian Albornoz ◽  
Johannes Glückler

We examine decision-making, shared authority, and pluralism as key characteristics for the effective co-management of natural resources. Drawing on the concept of network governance, we complement this approach by studying localized practices of governance that support existing and compensate for missing aspects in the regulation. The regime of territorial use rights for fisheries (TURF) in Chile is a recognized example of large-scale co-management that has given rise to local organizations that manage and exploit benthic resources. Based on multi-sited qualitative fieldwork across five regions, we analyze practices with respect to two governance objects: the deterrence of illegal fishing and the periodic assessment of the fisheries’ biology fields. Our analysis shows that local fisher organizations have institutionalized informal practices of surveillance and monitoring to fill in the gaps of existing regulations. Although fisher organizations and consultants—the so-called management and exploitation areas for benthic resources (AMERB)—have managed to operate the TURF regime, they depend on the government to enforce regulations and receive public subsidies to cover the costs of delegated governance tasks. We suggest that governance effectiveness could benefit from delegating additional authority to the local level. This would enhance the supervision of productive areas and better adaptation of national co-management regulations to the specific geographical context.


2019 ◽  
Vol 76 (6) ◽  
pp. 1601-1609 ◽  
Author(s):  
Tania Mendo ◽  
Sophie Smout ◽  
Tommaso Russo ◽  
Lorenzo D’Andrea ◽  
Mark James

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.


2013 ◽  
Vol 70 (2) ◽  
pp. 379-386 ◽  
Author(s):  
Espen Johnsen ◽  
Alf Harbitz

Abstract Johnsen, E., and Harbitz, A. 2013. Small-scale spatial structuring of burrowed sandeels and the catching properties of the dredge – ICES Journal of Marine Science, 70: 379–386. The lesser sandeel (Ammodytes marinus) remains burrowed for long periods in the seabed in sandy areas, and its habitat preference is reflected in a large-scale (10 km) patchy distribution in the North Sea. The small-scale spatial structure of sandeels in the seabed is less known. In this study, it was found that sandeel catches in grabs and dredges fit gamma distributions with a common shape parameter on both a 10 m and a 100 m scale. These spatial models were used to examine the catching properties of the dredge, which, in the new ICES sandeel assessment, is used to estimate recruitment and maturity curves. Analyses of the empirical data and simulations of the dredge and grab catch rates show very low dredge catchability (∼5%), but no length-dependent catchability in the dredge was found. However, analyses of the catch rates of parallel dredge hauls indicated increasing dredge catchability with sandeel density. The observed small-scale patchiness and the low and seemingly density-dependent dredge catchability result in biased abundance estimates with low precision. Therefore, we recommend a joint international effort to develop a more catch-efficient sampling dredge, where the effect of density on catchability is further examined.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Nicolas Acuña-Perales ◽  
Francisco Córdova-Zavaleta ◽  
Joanna Alfaro-Shigueto ◽  
Jeffrey C. Mangel

AbstractBetween October 2018 and October 2019, seven megamouth sharks were reported as bycatch in the small-scale surface and midwater gillnet fisheries operating from the ports of Mancora and Salaverry in northern Peru. Here we present details of these specimens and bycatch events that represent the first documented records of this species in Peruvian waters, confirming their occurrence as fisheries bycatch. We recommend continued monitoring programs in small-scale fisheries toward assessing the extent of this species’ occurrence in Peru and its vulnerability to fishery interactions.


2021 ◽  
Vol 13 (1) ◽  
pp. 68
Author(s):  
Nur Arina Hayati Mohidin ◽  
Sukree Hajisamae ◽  
Mazlan Hashim ◽  
Nik Aziz Nik Ali ◽  
Mohd Fazrul Hisam Abd Aziz

HighlightRay capture worldwide using variety fishing gear.Efficiency of fishing gear used in capture ray species among countries.The maturation size for female and male ray according to species present.Bycatch issues of elasmobranch in small and large scale fisheries.Suitable fishing gear to capture ray species at particular country.AbstractA coral reef is one of the important ecosystems. However coral Gillnets are usually used as a fishing gear by an artisanal fishery in Malaysia. This gear is commonly used by most countries. This paper discussed the rays capture worldwide by using a variety of fishing gear and also bycatch issues that commonly happen. The efficiency of the fishing gear used in capture ray species is compared and discussed among the countries. This paper distinguishes the maturation size for the female and male ray according to the species presence. The bycatch scenario is also discussed as the majority of this elasmobranch (shark and ray) which is caught as bycatch in both small scale fisheries (gill nets, long lines and hooks) and large scale fisheries (bottom trawl and purse seine). This paper explains the suitable type of fishing gear to use to capture ray species in a particular country.


2010 ◽  
Vol 11 (2) ◽  
pp. 225 ◽  
Author(s):  
K. ERZINI ◽  
J.M.S. GONCALVES ◽  
L. BENTES ◽  
P.G. LINO ◽  
J. RIBEIRO ◽  
...  

Parallel fishing trials with 0.30 mm diameter monofilament gill nets and longlines using small hooks were carried out in the Algarve (southern Portugal) over a one-year period, 1997-1998, with the objective of comparing species composition, catch rates, discards and size ranges. Four hook sizes of 'Mustad' brand, round bent, flatted sea hooks (numbers 15, 13, 12 and 11) and four mesh sizes of 25, 30, 35 and 40 mm (nominal bar length) of gill nets were used in the trials. Overall, 84 species were caught, with gill nets taking 71 species and longlines 54 species and with 41 species caught by both gears. The amount of discarding was higher for gill nets than for longlines. The catch species composition differed between the two gears, with the commercially valuable sea breams dominating the longline catches whereas small pelagics were relatively more important in the gill nets. Multivariate analysis showed a clear separation between the different sizes of the two gears both in terms of numbers and weights per species. Algarve gill netters and longliners fish the same species assemblage on the same fishing grounds, but have clearly different impacts in terms of catch species composition, catch rates and sizes. This information will be useful for the improved management of these small-scale, multi-species, multi-gear fisheries, where different gears compete for scarce resources. In particular this study provides a basis for a more rational allocation of licenses and control of fishing effort.


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