The efficacy of releasing caught Nephrops as a management measure

Castro, Margarida; Araújo, Artur; Monteiro, Pedro; Madeira, Ana Margarida; Silvert, William

Publication

The efficacy of releasing caught Nephrops as a management measure

2003Journal article

dc.contributor.author	Castro, Margarida
dc.contributor.author	Araújo, Artur
dc.contributor.author	Monteiro, Pedro
dc.contributor.author	Madeira, Ana Margarida
dc.contributor.author	Silvert, William
dc.date.accessioned	2017-01-17T13:57:05Z
dc.date.available	2017-01-17T13:57:05Z
dc.date.issued	2003
dc.description.abstract	The objective of this work was to examine if a policy of releasing caught lobsters, Nephrops, could be used to protect the Nephrops population off the south coast of Portugal. Such a measure, as an alternative to closing the fishery completely, would allow the continued operation of the fleet in targeting other species, resulting in a reduced economic and social impact compared with a complete closure. For such a proposal to be considered, information on survival rates of released lobsters is required. Nephrops were sampled randomly from the catch of commercial trawlers and put in cages, in an area with similar conditions to the area where they were caught, in order to evaluate survival rates. The cages were immersed for periods of 5–9 days. Several factors were considered to potentially affect survival, including duration of the tow and season, and biological characteristics of the individuals (e.g. size, sex and ovigerous condition). Survival was only affected by season (increased mortality inwarm months).Aglobal estimate of survival of released lobsters, taking into consideration survival and proportion of the catches for each season, was 35%. Simulation models were used to investigate the potential effect of a release measure on the population. Assuming the number of recaptured individuals is negligible, Z (instantaneous total mortality rate)would be considerably reduced if a release policy was implemented. This is particularly important if the levels of exploitation are high, which seems to be the case in this stock. It is our belief that the implementation of amanagement measure of returning all caught lobsters to the sea is worth considering as a means of aiding recovery of the resource. This measure would have the side effect of discouraging the choice of Nephrops as a target species, potentially reducing the fishing mortality even more significantly.	pt_PT
dc.description.version	info:eu-repo/semantics/publishedVersion	pt_PT
dc.identifier.doi	10.1016/j.fishres.2003.09.033	pt_PT
dc.identifier.other	AUT: MCA00514;
dc.identifier.uri	http://hdl.handle.net/10400.1/8943
dc.language.iso	eng	pt_PT
dc.peerreviewed	yes	pt_PT
dc.publisher	Elsevier	pt_PT
dc.rights.uri	http://creativecommons.org/licenses/by/4.0/	pt_PT
dc.subject	Nephrops norvegicus	pt_PT
dc.subject	Survival	pt_PT
dc.subject	Catch-release	pt_PT
dc.subject	Management	pt_PT
dc.title	The efficacy of releasing caught Nephrops as a management measure	pt_PT
dc.type	journal article
dspace.entity.type	Publication
oaire.citation.endPage	484	pt_PT
oaire.citation.issue	1-3	pt_PT
oaire.citation.startPage	475	pt_PT
oaire.citation.title	Fisheries Research	pt_PT
oaire.citation.volume	65	pt_PT
person.familyName	Castro
person.familyName	Monteiro
person.givenName	Margarida
person.givenName	Pedro
person.identifier.ciencia-id	971F-AF68-5799
person.identifier.orcid	0000-0002-7860-2074
person.identifier.orcid	0000-0003-1446-8256
person.identifier.rid	N-1091-2013
person.identifier.rid	D-4995-2009
person.identifier.scopus-author-id	7402292554
rcaap.rights	restrictedAccess	pt_PT
rcaap.type	article	pt_PT
relation.isAuthorOfPublication	76e4cab8-f3b7-4b85-b830-06599975ed40
relation.isAuthorOfPublication	4c74d67f-e46c-4536-81d5-27a047133d95
relation.isAuthorOfPublication.latestForDiscovery	76e4cab8-f3b7-4b85-b830-06599975ed40