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  • Effects of reallocating fishing effort from trawling to creels in a Norway lobster fishery
    Publication . Eichert, Moritz; Campos, Aida; Fonseca, Paulo; Lopes, Pedro; Marques, Lino; Castro, Margarida
    The consequences of reallocating fishing effort from trawling to creels in an area off the West coast of Portugal for the operation of the trawl fleet, as well as on the population dynamics and the global catch value for a high valued species, the Norway lobster (Nephrops norvegicus) are evaluated. The results suggest that only small portions of the area of interest are used by the trawl fleet, opening the possibility for a trawl ban without major disruption of the trawling activity. Economic benefits are expected, since predictions two scenarios tested, heavy and moderate exploitation, indicate no loss of catch value with much lower operational costs. Social benefits to local communities can also be expected since a much lower investment is needed for creel fishing, making this fishery attractive to small local companies already operating in the region. The proposed ban is consistent with the ecosystem approach to fisheries management and the Common Fisheries Policy (CFP) where the transition towards more responsible fishing practices is encouraged.
  • 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.