Science, Technology, and Society Initiative to minimize Unwanted Catches in European Fisheries

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Portuguese fisheries in seamounts of Madeira-Tore (NE Atlantic)

Publication . Campos, Aida; Lopes, Paulo; Fonseca, Paulo; Figueiredo, I.; Henriques, Victor; Gouveia, N.; Delgado, J.; Gouveia, L.; Amorim, A.; Araujo, G.; Drago, T.; dos Santos, A.

The activity of the Portuguese fishing fleet operating near seamounts of the Madeira Tore geologic complex was analyzed. The main objective is to identify the different fisheries taking place in the area, characterize the spatial patterns of vessels activity and estimate the fishing intensity, thus contributing to better inform management decisions. Vessel Monitoring System (VMS) and e-logbook data for the period 2012–2014 were used. The combined analysis of these data allowed the identification of fishing events and the estimation of the fishing intensity by gear type, as well as the characterization of general patterns relating to fishing operations. A total of 47 vessels displayed fishing activity in the studied area, mainly longliners based either on the mainland or the Madeira archipelago, visiting different seamounts in fishing trips lasting two to three weeks, and a few pole and line bait boats. Bottom and pelagic longlining alternate throughout the year, the former mostly in spring and summer, targeting the wreckfish Polyprion americanus and the European conger, Conger conger, while the latter is carried out in autumn and winter using a surface longline targeting the swordfish Xiphias gladius and a drifting longline set deeper in the water column, targeting the black scabbard fish Aphanopus carbo. A global evaluation of the fishing intensity and estimation of fishing impact in this area calls for the availability of VMS data, elogbooks and landing declarations from non-Portuguese fleets, making monitoring in these areas a top priority to assess the sustainability of human activities.

2019Journal article

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One device does not fit all: limited results of using a Sort-X grid in the multi-species trawl fishery in the Gulf of Cádiz

Publication . Gamaza, MariÁngeles; Fonseca, Paulo; Campos, Aida; Erzini, Karim; Sobrino, Ignacio

A Sort-X grid device with four different bar-spacing grids (25, 30, 40 and 50 mm) was tested in the Gulf of Cádiz (GoC) on-board commercial trawlers. A total of 83 fish, five crustacean and nine cephalopods species were sampled in 282 hauls. Most of the target and commercial bycatch species were sorted out by the grid with the exception of hake. Merluccius merluccius (L.). Additionally, common pandora, Pagellus erythrinus (L.), sardine, Sardina pilchardus (Walbaum), octopus, Octopus vulgaris Lamark, and cuttlefish, Sepia officinalis L., also showed a sizeable retention for some of the grid bar spacing. Statistical modelling of selectivity at length for hake found influence of depth on the selection parameters. Lengths at 50% retention for hake were estimated to be 27.4, 30.3, 36.3 and 42.3 cm TL for 25–50 mm bar spacing, respectively, all above the minimum conservation reference size (MCRS) in the GoC. The probability of hake contacting the grid was estimated as 0.95. Overall, although the selective device showed a good performance for hake, it is not appropriate for improving the fishing pattern of a multi-species trawl fishery such as that of the GoC.

2018Journal article

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Effects of different slipping methods on the mortality of sardine, Sardina pilchardus, after purse-seine capture off the Portuguese Southern coast (Algarve)

Publication . Marçalo, Ana; Guerreiro, Pedro; Bentes, Luis; Rangel, Mafalda; Monteiro, Pedro; Oliveira, Frederico; Afonso, Carlos; Pousao-Ferreira, Pedro; Benoit, Hugues P.; Breen, Mike; Erzini, Karim; Gonçalves, Jorge Manuel Santos

The effects of two different slipping methods on the survival, physical and physiological response of sardines, Sardina pilchardus, captured in a purse-seine fishery were investigated in southern Portugal. Sardines were collected and transferred into holding tanks onboard a commercial fishing vessel after being captured, crowded and deliberately released using two slipping procedures: standard and modified. The standard slipping procedure aggregated fish at high densities and made them "roll over" the floatline, while the modified procedure aggregated the fish at moderate densities and enabled them to escape through an opening created by adding weights to the floatline. Both slipping methods were compared with minimally harmed non-slipped sardines (sardines collected from the loose pocket of the purse seine). Survival rates were monitored in captivity over 28 days using three replicates for each treatment. The estimated survival of sardines was 43.6% for the non-slipped fish, 44.7% for the modified slipping and 11.7% for the standard slipping treatments. Scale loss indicated the level of physical impact experienced, with dead fish from the non-slipped and modified slipping technique showing significantly lower scale loss than those fish from the standard slipping treatment within the same period. Of the physiological indicators of stress measured, cortisol, glucose, lactate and osmolality attained peak values during slipping and up to the first hours after introduction to captivity. This work indicates that although delayed mortality after release may be substantial, appropriately modified slipping techniques significantly enhance survival of slipped sardines.

2018-05Journal article

Open Access

The MINOUWApp: a web-based tool in support of by-catch and discards management

Publication . D’Andrea, Lorenzo; Campos, Aida; Erzini, Karim; Fonseca, Paulo; Franceschini, Simone; Kavadas, Stefanos; Maina, Irida; Maynou, Francesc; Russo, Tommaso

Current fishing practices often do not allow adequate selection of species or sizes of fish, resulting in unwanted catches, subsequently discarded, with the consequent negative effects on both marine communities and fisheries profitability. The cross-analysis of density patches of potential unwanted catches and distribution of fishing effort can support the identification of spatial-temporal hot-spots in which the fishing pressure should be reduced to limit the amount of discards. The MinouwApp represents a technological and methodological framework to bring different, and structurally complex, sources of georeferenced data together into a simple visual interface aiming to interactively explore temporal ranges and areas of interest. The objective is to improve the understanding of fisheries dynamics, including discards, thus contributing to the implementation of discard management plans in a context of participative, ecosystem-based fisheries management strategies.

2020Journal article

Open Access

Marine spatial closures as a supplementary tool to reduce discards in bottom trawl fisheries: examples from southern European waters

Publication . Despoti, Smaragda; Milisenda, Giacomo; Ligas, Alessandro; Bentes, Luis; Maynou, Francesc; Vitale, Sergio; Garofalo, Germana; Sbrana, Mario; Erzini, Karim; Tserpes, George; Tsagarakis, Konstantinos; Maina, Irida; Pyrounaki, Maria-Myrto; Papadopoulou, Nadia; Machias, Athanassios; Colloca, Francesco; Fiorentino, Fabio; Stergiou, Konstantinos, I; Giannoulaki, Marianna

Discards is an important issue in fisheries around the world. the spatial management of discards has attracted interest as a potential tool for minimizing the unwanted catch. the aim of the present work was to identify areas with high quantities of bottom trawl discarded catch regarding species subjected to MCRS, in six areas of southern European waters (southern Portuguese waters, Catalan Sea, Ligurian and northern Tyrrhenian Seas, Strait of Sicily, eastern Ionian Sea, and Aegean Sea). Analyses were based on two types of data: (a) the undersized catch of species subjected to MCRS from bottom trawl surveys and (b) the actual discarded catch (including undersized and non-undersized individuals) of species subjected to MCRS from commercial bottom trawling. Geostatistical analysis techniques were applied to the first type of data and Generalized Additive Models using environmental variables were applied to the second one. Subsequently, areas that persistently presented high quantities of discarded catch (i.e., "iDC grounds") or undersized catch (i.e., "iUC grounds") were identified and mapped. the "iDC grounds"/"iUC grounds" were located either over the slope or within the continental shelf and over marine plateaus, largely depending on the main target species of each fishery. Next, the overlap of "iDC grounds"/"iUC grounds" with the existing Fisheries Restricted Areas (FRAs) and the proposed Marine Protected Areas (MPAs) was estimated aiming to explore how spatial closures could contribute to the reduction of bottom trawl discarded catch/undersized catch. Certain spatial closures were more effective in the Central Mediterranean and others to the Eastern Mediterranean. the overlapping of existing FRAs with "iDC grounds"/`iUC grounds" did not exceed 24 % in any study area, whereas proposed MPAs, like the CIESM Marine Peace Parks, reached up to 90 % for the same study area.

2020-12Journal article

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