Is square-mesh better selective than larger mesh? A perspective onthe management for Mediterranean trawl fisheries

tRelatively little scientific work has been done to assess the selectivity of square-mesh codends in thehighly variable multi-species conditions in the Italian trawl fisheries. Therefore this study was initiatedto investigate the effect of using square-mesh and larger diamond-mesh codends on size selectivity ofdeepwater red shrimp (Aristaeomorpha foliacea) and red mullet (Mullus barbatus), with possible impli-cation in future management measures. Four different codends were used in the sea trials. When sizeselection estimates are applied for management issues it is not sufficient only to consider the mean sizeselection parameters. It also needs to consider the effect of between-haul variations in the selection pro-cess. In the current study, potential consequences of the between-haul variation on the selection curveshave been considered by applying a pooled curve with a double bootstrap approach. The results attainedin the present study indicate that the use of 40 mm square-mesh codend results in a 50% retention length(L50) similar to that of the 50 mm diamond-mesh codend, but with a steeper selection range (SR). For redmullet, both 50 mm diamond-mesh and 40 mm square-mesh codends lead to an L50 that is higher thanthe minimum landing size (MLS, 11 cm). Deepwater red shrimp is not subject to any MLS and may alwaysbe landed legally. However, large amounts of juveniles of deepwater red shrimp have been retained in allcodends.

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Tests of artificial light for bycatch reduction in an ocean shrimp(Pandalus jordani) trawl

The addition of artificial light in the vicinity of the rigid-grate bycatch reduction device (BRD) and along the fishing line of an ocean shrimp (Pandalus jordani) trawl altered fish bycatch and ocean shrimp catch. In separate trials using double-rigged shrimp nets, with one net incorporating artificial lights and the other serving as a control, the investigators 1) attached one to four Lindgren-Pitman Electralume® LED lights (colors green or blue) in locations around the rigid-grate BRD, and 2) attached 10 green lights along the trawl fishing line. Both experiments were conducted with rigid-grate BRDs with 19.1 mm bar spacing installed in each net. Contrary to expectations, in 12 paired hauls the addition of artificial light around the rigid-grate increased the bycatch of eulachon (Thaleichthys pacificus), a threatened anadromous smelt species, by 104% (all by weight, P = 0.0005) and slender sole (Lyopsetta exilis) by 77% (P = 0.0082), with no effect on ocean shrimp catch or bycatch of other fishes (P > 0.05). In 42 paired hauls, the addition of 10 LED lights along the fishing line dramatically reduced the bycatch of a wide variety of fishes with no effect on ocean shrimp catch (P > 0.05). Bycatch of eulachon was reduced by 91% (P = 0.0001). Bycatch of slender sole and other small flatfishes were each reduced by 69% (P < 0.0005). Bycatch of darkblotched rockfish (Sebastes crameri), a commercially important but depressed rockfish species, was reduced by 82%(P = 0.0001) while the bycatch of other juvenile rockfish (Sebastes spp.) was reduced by 56% (P = 0.0001). How the addition of artificial light is causing these changes in fish behavior and bycatch reduction is not known. However, in both experiments the addition of artificial light appears to have greatly increased the passage of fishes through restricted spaces (between BRD bars and the open space between trawlfishing line and groundline) that they typically would not pass through as readily under normal seafloor ambient light conditions.

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A quantitative and qualitative assessment of the discard ban in European Mediterranean waters

The new Common Fisheries Policy aims to reduce the discard rate in Europe, and one way in which it seeks to achieve this goal is by making it compulsory to land all species subject to catch limits, and some of species managed by minimum catch size. The characteristics of the Mediterranean Sea raise serious concerns over the viability, efficacy and consequences of these measures, and the purpose of this study is therefore to analyse these with a view to improving discard management in this region. The Port of Santa Pola was chosen as a reference fishing port in the Spanish Mediterranean for quantitative analysis, comparing all the species caught with those proposed by the CFP.

The governing system should take in to consideration the contextualization of discard management according to the specific characteristics of each métier; coordination between stakeholders; and caution about the ecological cost of landing discards. The high logistical, surveillance, monitoring and ecological costs  produce a negative outcome despite the objective pursued, the willingness of the fishing industry to reduce discards and the profitable use of the resource by its proposed end users. This may lead to the measure proving unviable in the Mediterranean Sea and its ensuing failure to reduce discards.

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Short-term effect of selectivity change in a trawling fishery in the Western Mediterranean

The change of mesh size or shape as a management measure to improve selectivity as proposed by the EU should be assessed using actual fishery data, despite being tested experimentally in previous studies. Four metiers were identified in the fishery: European hake (Merluccius merluccius), red mullet (Mullus barbatus), red shrimp (Aristeus antennatus) and Norway lobster (Nephrops norvegicus). No significant differences were observed in biomass or income owing to the new mesh in either European hake or red mullet. In contrast, the total biomass of the red shrimp metier and the biomass of the Norway lobster, Nephrops norvegicus, were significantly higher after the selectivity change. Regarding the catch composition, only the European hake metier showed slight – but not significant – changes after using the new mesh. Considering these results, there was no short-term effect (substantial biological or economic loss) as previous studies had expected. This could possibly be related to a higher performance of the new gear that may compensate for the lower retention of small sizes.

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Seafood CRC Final Report of Bioeconomic Workshop

The Institute of Marine and Antarctic Studies (IMAS) at the University of Tasmania organized a bio-economic workshop for fisheries managers. It was attended by fisheries managers from the eight Australian jurisdictions, invited speakers including prominent international fisheries economists Ralph Townsend (University of Winona, U.S.) and Seth Macinko (University of Rhode Island, U.S.)

At the workshop, participants discussed the importance of economic objectives and the role of government and industry in attaining those objectives. It was highlighted that many jurisdictions do not have operational economic objectives in fisheries management plans or harvest strategies. It was also advised that the National Strategy Guidelines have been released with the aim to increase the use of economic and social indicators or target reference points within harvest strategies, as required under an Ecological Sustainable Development (ESD) framework. Participants identified that the historical focus of management has been on ensuring biological objectives are met and this has meant that less money has been allocated to economic and social research. A presentation from Econsearch, who have been collecting economic data from the commercial fishing industry in South Australia for the last 17 years, discussed the value of a time series of economic data that can increase the credibility of industry when discussing marine resource use with government. This data can be collected at a low costs relative to biological data and in South Australia is funded through licence fees.

Participants learnt how economic analyses, such as bio-economics, can identify management changes that can improve fishery yield.”

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ICES latest CRR focuses on cephalopod species.

ICES Working Group on Cephalopod Fisheries and Life History(WGCEPH), chaired by Marina Santurtún and Jean-Paul Robin, studies and compiles information on cephalopod biology and ecology and the fisheries and regulations that can affect them.​

Cephalopods are short-lived marine invertebrates, characterized by a high metabolic rate, fast growth, and sensitivity to environmental change, which result in highly variable levels of abundance. In the last 2 years, within the groups work related to the MSFD, the use of cephalopods as indicators for ecosystem biodiversity (D1), sustainable fisheries (D3), trophic interactions (D4), contaminants in seafood (D9), underwater noise (D11), and changes in hydrographical conditions (D7) appear to be adequate.

In 2015, WGCEPH will also work on providing information about the state of cephalopod diversity in Eco-Regions like the North Sea, Baltic Sea, Celtic Seas and Bay of Biscay and the Iberian coast. The authors have generated a compact, comprehensive, and up-to-date set of reviews covering relevant biological and ecological information on exploited European cephalopods. This CRR falls between the short accounts issued by FAO and the more detailed and discursive species reviews that have appeared in journals and books over the years.

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Majorcan case studies

Monitoring unwanted catches from trammelnets has been launched at Mallorca. An on-board observer is monitoring wanted and unwanted catches twice a week. We are constrained for the fishers in the sense that sampling design is imposed by fisher’s choice. We are quantifying commercial and non-commercial fish (species-level identification). When possible, a photo of the non-commercial fraction is taken and the weight/size of the commercial part is recorded. Concerning invertebrates, commercial catches are counted but a 5 liters sample of small non-commercial is keep and the total volume is measured. Provided that boats are very small, we are implementing a voice-based recording system: an application for smart phone allows to link both, voice files and pictures with date:time and GPS position. Metadata (net details, fishing strategy, environmentla variable...) are keept. We are planning to continue with this monitoring plan for at least one year.

Minouw project kick-off meeting
Photo with participants to the kick-off meeting

The project kick-off meeting took place in Palma de Mallorca (Spain) from 13 to 16 April.

European Parliament delays discards sanctions

The European Parliament has agreed to give fishermen two years to ‘adapt’ to the new discard ban before sanctions for failing to comply take effect.

Project starts march 1, 2015: on february 26, 2105

The European Commission signed accession to the GA and appointed march 1, 2015 as starting date for the project.