Suchergebnisse

The Striped Venus Clam, Chamelea gallina, is one of the most important commercial bivalve species of the Verenidae family in the Mediterranean. It was suggested for the first time as potential candidate for exploitation from its natural fisheries and for possible aquaculture in Egypt (FAO EastMed 2014). The present study was conducted to investigate the heavy metals concentrations in Chamelea gallina from natural fisheries to evaluate its safety for human consumption as potential bivalve resource for exploitation in Egypt. Chamelea gallina was sampled from 12 transects representative of about 60 km along the Mediterranean coast between Rasheed (Rosetta) and Burullus from 31.45874 N and 30.50054 E to 31.59596 N and 30.94383 E. Clams soft tissues were analyzed for the levels of eight heavy metals; four hazardous metals [lead (Pb), cadmium (Cd), Mercury (Hg) and chromium (Cr)] and four essential metals [copper (Cu), manganese (Mn), iron (Fe) and zinc (Zn)] using SHIMADZU Atomic Absorption Spectrophotometer. Results were compared to authorities' maximum permissible limits as set by different organizations of different countries on both dry weight (d.w) and wet weight (w.w.) basis. Results showed that the examined bivalve fisheries are considered clean compared to other areas of the world. They are considered safe for human consumption considering the FAO/WHO, USFDA and other regulations from different countries of the world. However, in few cases they failed to be approved for the European regulations which are the most strict legislations. Spatial distribution of heavy metals in clams across the investigated area showed that the clams are in general within safe limits especially in the western and middle parts of the investigated area from Rasheed eastwards. This zone have the maximum biomass of C. gallina as confirmed by a simultaneous fishery study (FAO EastMed 2014). This indicates that, Chamelea gallina in this zone is safe for human use and might provide promising fisheries for exploitation when toxic risk of the most hazardous heavy metals such Hg, Cu, Cr and Zn are concern. However, the eastern part of the studied area near Burullus must be monitored for Pb contamination and sources. Then, collection of C. gallina should be avoided when necessary.

Prior to joining the European Union, Malta operated a 25nm Exclusive Fishing Zone that was retained as a Fisheries Conservation Zone (FCZ) following EU membership. The present study was conducted in this FCZ as part of the ongoing MEDITS trawl survey programme. Otter trawl samples were collected from muddy bottoms at depths of 100-300m. The catch from each haul was sorted into commercial and non-commercial components, and fauna were identified and counted. Samples for analyses of infauna and sediment characteristics were collected using a 0.0625m² capacity box-corer. Macrofaunal abundance data for the stations were analysed using ordination techniques (nMDS) and relationships between environmental variables and faunal assemblages were explored by superimposing individual variables on the two-dimensional nMDS plots. The analyses clearly separated the commercial species into two distinct groups of assemblages that seemed to be defined principally by depth: those from inshore and south-eastern stations (depth range 100-250m) and those from north-western stations (depth range 250-300m). The non-commercial species showed a similar pattern with assemblages from inshore stations grouping together; however, the offshore stations had a greater variability in non-target species composition, especially for infauna. For the offshore stations, geographical position seemed to be important since stations off the north-western coast of the Maltese islands grouped separately from those off south-eastern Malta. ; peer-reviewed

The migration of Lessepsian species, which was the result of the opening of the Suez Canal in 1869 and further facilitated by human activities and environmental conditions, seems to play a key role for fisheries particularly in the Levant basin. However, there is still lack of accurate data for most of the Lessepsian species in order to evaluate their positive or negative effect to the fisheries catches and local fish stocks. The Project "Scientific and Institutional Cooperation to Support Responsible Fisheries in the Eastern Mediterranean- EastMed has been declared in September 2009, is executed by the Food and Agriculture Organization of the United Nations (FAO) and funded by Greece, Italy and EC. A network of experts on the effect of Lessepsian species on fisheries of the Eastern Mediterranean (NELESFISH) was established following a sub-regional technical meeting of the FAO-EastMed Project on "The Lessepsian Migration and its Impact on Eastern Mediterranean Fishery", that took place in Nicosia, Cyprus, in December 2010 and was attended by experts from Cyprus, Egypt, Gaza Strip and West bank, Greece, Italy, Lebanon and Turkey. According to the review of available information during the meeting, the Lessepsian migrants caught by fishing gears include nowadays 77 fish and 24 invertebrate species; their numbers are increasing from year to year. Some Lessepsian species, like Siganus spp., Marsupenaeus japonicus, Saurida undosquamis, Etrumeus terres, Upeneus spp., have been successfully introduced into local markets, constituting important resources for fisheries in some countries. Others, like Fistularia commersoni, are landed or discarded depending on the demand in the local markets and require some marketing to increase their commercialization. Some venomous species, like for example Lagocephalus sceleratus and Rhopilema nomadica, apart from being hazardous to human health, are causing damages to fishing gears and commercial catches, particularly of some coastal fisheries in the Levant basin. Among the main objectives of the network of experts are the standardization of methodology for the collection of data aiming to the quantification of Lessepsian migrants and their effects on fisheries, the development of a database with relative literature and legislation and the contribution of recommendations within the framework of the FAO EastMed project towards the minimization of negative effects of Lessepsian migration and the adaptation of fisheries to this phenomenon.

The migration of Lessepsian species, which was the result of the opening of the Suez Canal in 1869 and further facilitated by human activities and environmental conditions, seems to play a key role for fisheries particularly in the Levant basin. However, there is still lack of accurate data for most of the Lessepsian species in order to evaluate their positive or negative effect to the fisheries catches and local fish stocks. The Project "Scientific and Institutional Cooperation to Support Responsible Fisheries in the Eastern Mediterranean- EastMed has been declared in September 2009, is executed by the Food and Agriculture Organization of the United Nations (FAO) and funded by Greece, Italy and EC. A network of experts on the effect of Lessepsian species on fisheries of the Eastern Mediterranean (NELESFISH) was established following a sub-regional technical meeting of the FAO-EastMed Project on "The Lessepsian Migration and its Impact on Eastern Mediterranean Fishery", that took place in Nicosia, Cyprus, in December 2010 and was attended by experts from Cyprus, Egypt, Gaza Strip and West bank, Greece, Italy, Lebanon and Turkey. According to the review of available information during the meeting, the Lessepsian migrants caught by fishing gears include nowadays 77 fish and 24 invertebrate species; their numbers are increasing from year to year. Some Lessepsian species, like Siganus spp., Marsupenaeus japonicus, Saurida undosquamis, Etrumeus terres, Upeneus spp., have been successfully introduced into local markets, constituting important resources for fisheries in some countries. Others, like Fistularia commersoni, are landed or discarded depending on the demand in the local markets and require some marketing to increase their commercialization. Some venomous species, like for example Lagocephalus sceleratus and Rhopilema nomadica, apart from being hazardous to human health, are causing damages to fishing gears and commercial catches, particularly of some coastal fisheries in the Levant basin. Among the main objectives of the network of experts are the standardization of methodology for the collection of data aiming to the quantification of Lessepsian migrants and their effects on fisheries, the development of a database with relative literature and legislation and the contribution of recommendations within the framework of the FAO EastMed project towards the minimization of negative effects of Lessepsian migration and the adaptation of fisheries to this phenomenon.