Razmnožavanje kozice Penaeus (Melicertus) kerathurus u zaljevu Amvrakikos, zapadna Grčka

The reproduction of the karamote prawn, Penaeus (Melicertus) kerathurus (Forskål 1775), was studied for the native population in Amvrakikos Gulf (Ionian Sea; western Greece). Sampling was carried out on a monthly basis between June 1999 and May 2001. The results showed that the shrimp Penaeus (Melicertus) kerathurus reproduction period spans between late April and late September. The size-at-maturity was estimated at a size of 45.23 mm carapace length (or 156.2 mm in total length). The smallest mature female in the samples was found to have 30 mm CL or 113.95 mm TL. Maximum gonadosomatic index (GSI) was estimated to be 9.62% for female shrimps at stage IV gonad maturity stage. The population gonadosomatic index peaks in May with an average value of 6.895%. Potential fecundity was estimated to be 154600 of oocytes per g of gonad tissue at the stage IV (mature female). Monthly sex ratios (males/females) were found greater than 1 throughout the year with maximum values reaching 2.5. A new life cycle pattern is proposed for this particular population.Razmnožavanje kozice, Penaeus (Melicertus) kerathurus (Forskål, 1775), je istraživano na populacijama iz prirodne sredine na području zaljeva Amvrakikos (Jonsko more, zapadna Grčka). Uzorkovanje je obavljeno svakog mjeseca u razdoblju između lipnja 1999. godine i svibnja 2001. godine. Rezultati istraživanja pokazuju da se kozica mrijesti u razdoblju travanj-rujan. Veličina pri kojoj kozica dosiže spolnu zrelost iznosi 45.23 mm dužina karapaksa (156.2 mm ukupna dužina). Utvrđena je najmanja spolno zrela ženka u uzorku pri dužini 30 mm dužina karapaksa (113.95 mm ukupna dužina). Najveća izračunata vrijednost gonadosomatskog indeksa iznosi 9.62% za ženke pri stadiju IV zrelosti gonada. Gonadosomatski indeks za čitavu populaciju ima svoj maksimum u svibnju pri srednjoj vrijednosti od 6.895%. Izračunati potencijalni fekunditet iznosi 154600 oocita po gramu tkiva gonada pri stadiju IV (zrela ženka). Mjesečni omjer spolova (mužjak/ženka) ima vrijednosti veće od 1 tijekom cijele godine uz maksimalnu vrijednost 2.5. Iznesen je i predložak obrasca novog životnog ciklusa populacije na istraživanom području

Mejora de stocks en el sudeste del Mar Negro, mediante la liberación de rodaballos, Psetta maxima, criados en cautividad: análisis de la captura, migración, crecimiento y dieta

In this study, the capture, growth, migration and diet of hatchery-released turbots (Psetta maxima) were examined in the southeastern Black Sea region for six years (2009-2014). A total of 9933 turbots were marked with individual serial-numbered T-bar anchor tags and released at Trabzon, Turkey. The mean TL and weight of the released turbots were 12.91 cm (±1.25) and 35.41 g (±12.38) and the same measurements for the captured turbots were 31.17±0.86 cm and 878.08±69.47 g, respectively. A total of 2.7% (270 fishes) of the tagged individuals were captured during the study period and the age of the captured tagged fishes was between 0+ and 5+ years. Growth of the captured turbots was analytically examined. Movements of the tagged turbots were expressed as “resident” and “migratory”. Three prey groups showed the majority of forage organisms; teleost fishes, crustaceans and mollusks in the stomach of the captured turbots. The hatchery-released turbots might be used for stock enhancement due to their high growth rate and commercial value, and their relatively limited migration range.En este estudio se examinaron datos de captura, crecimiento, migración y dieta, de rodaballos (Psetta maxima) criados en cautividad y liberados en zonas del sudeste del Mar Negro, durante seis años (2009-2014). Se marcaron individualmente un total de 9933 rodaballos, utilizando marcas numeradas en serie (marcas de plástico tipo T) y se liberaron en Trabzon (Turquía). Las medias de longitud total (TL) y peso total de los rodaballos liberados fueron de 12.91 cm (±1.25) y 35.41 g (±12.38), y las mismas medidas para los rodaballos capturados fueron de 31.17±0.86 cm y 878.08±69.47 g, respectivamente. Un 2.7% (270 peces) de los individuos marcados fue capturado durante el periodo de estudio y la edad de estos individuos osciló entre 0+ y 5+ años de edad. El crecimiento de los rodaballos capturados se examinó analíticamente. Los movimientos de los rodaballos marcados fueron expresados como “residentes” y “migratorios”. La mayoría de los organismos presentes en los estómagos de los rodaballos capturados pertenecían a tres grupos de presas: peces teleósteos, crustáceos y moluscos. Los rodaballos criados en cautividad y liberados podrían ser usados en la mejora de stocks debido a su elevada tasa de crecimiento, valor comercial, y su relativamente limitado rango de migración

On the Atlantic blue crab (Callinectes sapidus Rathbun 1896) in southern European coastal waters: Time to turn a threat into a resource?

[EN] The blue crab Callinectes sapidus is native to the coastal waters of the western Atlantic Ocean, and along the US coasts the species supports an important fishery. The crab was introduced to Europe at the beginning of the 20th century. To date, the species is considered invasive and it has been extensively recorded in southern European waters (SEW), where it is starting to penetrate the shellfish market. Here, an integrated management strategy is proposed for the blue crab in SEW, including the Mediterranean and Black Sea and the eastern Atlantic coasts of the Iberian Peninsula. Taking as introductory examples two case studies represented by the red king crab Paralithodes camtschaticus and the green crab Carcinus maenas, a framework of key issues is reviewed, considering the double nature of the species as invaders and shellfish products. A SWOT analysis is eventually presented for C. sapidus, in order to perform a state-of-the-art synthesis of the proposed scenario, highlighting the potential opportunities as well as the weaknesses related with the limited knowledge of the ecological and economic impact of the species in invaded habitats. The review is concluded by an appraisal of the current trends in global and European crustacean fisheries. The ongoing expansion of C. sapidus might represent a useful management case study, where the need to control an invasive species and mitigate its ecological impact can be harmonized with the opportunity to value it as a fishery resource.Funding from FUR 2013-2014 and 2015-2016 to G. M. is acknowledged. The European Fisheries Fund (FEP) Puglia Region (Italy) supported L. C. (CIP 04/OPI/010). The Portuguese Science Foundation (FCT) supported F. R. (SFRH/BPD/46761/2008). F. R. and P. C. were also supported by the strategic MARE plan Marine and Environmental Sciences Centre (UID/MAR/04292/2013). Constructive comments from two anonymous reviewers on an earlier version of the paper are gratefully acknowledged. This paper is dedicated to Sofia Mancinelli, thy eternal summer shall not fade.Mancinelli, G.; Chainho, P.; Cilenti, L.; Falco, S.; Kapiris, K.; Katselis, G.; Ribeiro, F. (2017). On the Atlantic blue crab (Callinectes sapidus Rathbun 1896) in southern European coastal waters: Time to turn a threat into a resource?. Fisheries Research. 194:1-8. https://doi.org/10.1016/j.fishres.2017.05.002S1819

A bio-economic evaluation of the potential for establishing a commercial fishery on two newly developed stocks: the Ionian Red Shrimp Fishery

It has recently been shown that two deep-water red shrimp species (Aristeus antennatus and Aristaeomorpha foliacea) have the potential to support a viable fishery in the Greek Ionian Sea (eastern Mediterranean). In this article, we investigate (i) the evolution that this newly developed trawl shrimp fishery may undergo when subjected to different management measures, and (ii) the most suitable extraction rates considering the uncertainties about the resource. We further analyse the effects that potential future fuel price increases and changes in the market may have on the fishery. Forecasting the biological and economic consequences of management actions, as well as the effects of market changes on inputs and outputs before they are applied, may help managers select the most suitable management options. We approach the problem by means of bio-economic simulation analysis. The results of this study show that fishing effort can increase by 50-100%, increasing the fleet's profitability without jeopardizing the sustainability of the fishery

Dekapodni rakovi u zaljevu Argolikos (istočni dio Sredozemnog mora, središnji dio Egejskog mora)

The study presents the biomass, the abundance and the depth distribution of the decapod crustaceans in Argolikos Gulf (Central Aegean Sea) from data collected in trawl surveys carried out throughout 2008. This work is the first systematic work in this important Greek area and will support the knowledge for understanding the decapods stocks’ fishery in the above area. A total of 28 species of decapod crustaceans was identified from a total of 42 hauls made in three depth zones (50-100 m, 100-200 m, 500-600 m). Among decapods recorded were 6 Dendrobranchiata (5 Penaeoidea, 1 Sergestoidea), 22 Pleocyemata (9 Brachyura, 8 Caridea, 2 Anomura, 1 Palinurid, 1 Astacideum, 1 Stenopodidea). The most abundant commercial species found in both shallower depth zones (50-100 m, 100-200 m ) was Parapenaeus longirostris while in the deepest one (500-600 m) Aristaeomorpha foliacea was the most numerous. Some new depth distribution records for the Eastern Mediterranean were obtained for some few species.U ovom radu su prikazani biomasa, abundancija i dubinska raspodjela dekapodnih rakova u Argolikos zaljevu (središnji dio Egejskog mora) dobiveni iz podataka prikupljenih povlačnim alatima tijekom 2008. godine. Ovaj rad je prvi sustavni rad, iz ovog važnog grčkog područja, koji donosi saznanja za bolje razumijevanje dekapodnih zaliha. Ustanovljeno je 28 vrsta dekapodnih rakova tijekom 42 koćarska potega na tri dubine (50-100 m, 100-200 m, 500-600 m). Zabilježene su slijedeće vrste dekapodnih rakova: 6 Dendrobranchiata (5 Penaeoidea, 1 Sergestoidea), 22 Pleocyemata (9 Brachyura, 8 Caridea, 2 Anomura, 1 Palinurid, 1 stacideum, 1 Stenopodidea). Najbrojnija komercijalna vrsta koja je pronađena u obje pliće zone (50-100 m, 100-200 m) je P. longirostris, dok je u najdubljoj zoni (500-600 m) bio najbrojniji A. foliacea. Tijekom istraživanja u istočnom Sredozemnom moru su ustanovljeni novi nalazi o raspodjeli nekih vrsta prema dubini

Recreational sea fishing in Europe in a global contextParticipation rates, fishing effort, expenditure, and implications for monitoring and assessment

Marine recreational fishing (MRF) is a high-participation activity with large economic value and social benefits globally, and it impacts on some fish stocks. Although reporting MRF catches is a European Union legislative requirement, estimates are only available for some countries. Here, data on numbers of fishers, participation rates, days fished, expenditures, and catches of two widely targeted species were synthesized to provide European estimates of MRF and placed in the global context. Uncertainty assessment was not possible due to incomplete knowledge of error distributions; instead, a semi-quantitative bias assessment was made. There were an estimated 8.7 million European recreational sea fishers corresponding to a participation rate of 1.6%. An estimated 77.6 million days were fished, and expenditure was Euro5.9 billion annually. There were higher participation, numbers of fishers, days fished and expenditure in the Atlantic than the Mediterranean, but the Mediterranean estimates were generally less robust. Comparisons with other regions showed that European MRF participation rates and expenditure were in the mid-range, with higher participation in Oceania and the United States, higher expenditure in the United States, and lower participation and expenditure in South America and Africa. For both northern European sea bass (Dicentrarchus labrax, Moronidae) and western Baltic cod (Gadus morhua, Gadidae) stocks, MRF represented 27% of the total removals. This study highlights the importance of MRF and the need for bespoke, regular and statistically sound data collection to underpin European fisheries management. Solutions are proposed for future MRF data collection in Europe and other regions to support sustainable fisheries management.Institut Francais de Recherche pour l'Exploitation de la Mer; French Ministry of Fisheries Management; Greek National Data Collection Programme; European Commission, Data Collection Framework; Department for Environment, Food and Rural Affairs [MF1221, MF1230, MI001]; Norges Forskningsrad [267808]; State Department of Agriculture, Food Security and Fisheries Mecklenburg-Western Pomerania; Interreg IVa 2 Seas; Dutch Ministry of Economic Affairs; European Fishery Fund; Government of Galicia [ED481B2014/034-0