Dnevna slika migriranja kratkorepog raka, Maja crispata, Risso 1827 (Brachyura, Majidae)

Occurrence, distribution, and assemblage of crustaceans in the southern Adriatic Sea were determined from data collected during five seasonal (summer) trawl surveys carried out during 1996-2000. Trawls were conducted at a bathymetric range of 10-800 m, by the same vessel and same sampling gear in the framework of the E.U. Project, MEDITS. Fifty-two benthic-epibenthic, and nektonic species (three stomatopods, 49 decapods) were caught. Species density data (individuals per km2) were processed according to multivariate techniques to describe the composition and distribution of main pecies assemblages. The assemblages were consistent throughout the surveyed area with some differences between the western and eastern zones, mostly those found on shelf bottoms. The influence of oceanographic features, other than depth, is discussed.U sjevernom Jadranu su promatrana dnevna pomicanja populacije brahiurnog raka, Maja crispata. Odnos spolova, mužjaka prema ženkama, iznosio je 3:2. Mužjaci su imali maksimalnu dužinu oklopa 91 mm, a ženke 74 mm. Maja crispata češće se nalazila na šljunkovitom dnu nego na bilo kojem drugom habitatu. Sedmero promatranih primjeraka nije se pomicalo prema nekom određenom području, nego se zadržavalo većim dijelom na tvrdom supstratu, između 0,8 i 3,5 m dubine. Maksimalna udaljenost od početnog položaja postignuta je u 9 dana, a iznosila je 16 metara

Stock status and potential yield of deep water rose shrimp (Parapenaeus longirostris, Lucas 1846) in the south-central Mediterranean Sea

This document summarises the data used, methods adopted and the results of the joint stock assessment carried out during the MedSudMed and CopeMed II Working Groups on Parapenaeus longirostris and related fisheries held in 2009 and 2010 in Malta and Italy respectively. The aim of this document is to describe the state of the stock of P. longirostris in the south-central Mediterranean Sea using data from Italy, Tunisia and Malta. The long term objective of this study is to provide the baseline for the establishment of a harmonised management regime for the deep water rose shrimp fishery in the south-central Mediterranean Sea. Overall, fishery dependent data from Italy, Malta and Tunisia for the first time were pooled together and jointly processed. The assessment was performed using length cohort analysis (LCA) and biomass and yield per recruits analyses as implemented in VIT4Win. Current mean fishing mortality and exploitation pattern were assessed using the steady state LCA on length frequency distributions (LFD) of 2007, 2008 and 2009 as well as the average 2007-2009 catches, raised to the total landings. Analyses were performed separately by keeping sex and fleet segments separate (i.e. Italy 12-24; Italy > 24; Tunisia; Malta) as first step. A sensitivity analysis was also carried out as implemented in VIT. The results are discussed in the view of providing robust technical advice for the management of national fisheries exploiting P. longirostris in the MedSudMed area taking into account the possible evolution of national fisheries. Some perspective for future joint activities to be carried out within the cooperative framework established by the FAO Projects are also presented.peer-reviewe

World squid fisheries

Peer reviewedPublisher PD

Ecological-Fishery Forecasting of Squid Stock Dynamics under Climate Variability and Change: Review, Challenges, and Recommendations

World Fisheries Congress 2021 (WFC), 20-24 September, onlineN

Effects of Climate Variability and Change on the Population Dynamics of Cephalopods and a Predictive and Forecast Framework to Inform Fisheries Management

AFS Global Conference, 22-23 October 2020, onlineN

Ecological-Fishery Forecasting of Squid Stock Dynamics under Climate Variability and Change: Review, Challenges, and Recommendations

24 pages, 3 figures, 5 tablesGlobally, cephalopods support large industrial-scale fisheries and small-scale to partly large-scale local artisanal fisheries. They are of increasing economic importance as evidenced by the rapid rise in their global landings from 1950 to 2014. Cephalopods are sensitive to environmental variability and climate change and many if not all species show wide fluctuations in abundance. This is most evident in ommastrephid nerito-oceanic squid since their life cycle is associated with boundary currents that are changing with climate change. The inter-annual variability in catch presents challenges for fishers and managers due to the ‘boom-or-bust’ nature of the fishery. A key barrier to rational management of squid fisheries is the low level of development of fishery forecasting. Despite substantial progress made in relating squid population dynamics to environmental variability and change, several challenges remain to develop forecast products to support squid fisheries management. Ideally, squid fisheries management needs a forecasting system that includes all time-scales of forecasting, and especially short - and medium-terms forecasts. The present overview first provides current knowledge of the effects of climate change and variability on squid population dynamics, challenges and opportunities to advance ecological-fishery forecast products, and finally a roadmap is proposed for future development of forecasts products to support squid sustainable fisheries management. As for the adoption of specific forecasting methods to the squid fishery management process, what is important is the relationship between needs, feasibility, and the ultimate success of a forecast will be determined by whether it is used by end-usersPeer reviewe

Synthesis of information on some demersal crustaceans relevant for fisheries target species in the south-central Mediterranean Sea

This document reviews and compiles the scientific information on some demersal crustaceans relevant for fisheries target species in the south-central Mediterranean Sea: Aristaeomorpha foliacea; Melicertus (Penaeus) kerathurus; Metapenaeus monoceros; Nephrops norvegicus; Palinurus elephas and Parapenaeus longirostris. The document provides a description of each species including bio-ecology, life history parameters, fishery exploitation and fishing gear selectivity information. Scientific information was organized to provide a synthetic outline on each species, including meristic description, ecology (geographical distribution, habitats), biogical information (maximum size, spawning activity, length at first maturity, recruitment at habitat and nurseries, sex ratio, length-weight relationship, maximum age and natural mortality, von bertalanffy growth function, feeding behaviour, stock units). Information on stock status and exploitation when available (abundance indices from trawl surveys, strength of recruitment, stock assessment, fisheries, fishing zones and seasons, yield, fishing and discards) is also provided per species. This work is the result of international scientific cooperation among the fishery research institutions participating in the FAO-MedSudMed Project.peer-reviewe