Radiological risks assessment due to natural radioactivity in Mediterranean sea fishes

Background and Objectives: In this article a comprehensive study was carried out for the determination of natural radioactivity in Mediterranean sea fishes and the evaluation of radiological health risks due to their ingestion. All analyzed samples came from the Calabria region, southern Italy, and, in particular, from the district of Reggio Calabria. Method: A total of seventy representative samples, five for each investigated species (Sardina Pilchardus, Mugil Cephalus, Scomber Scombrus, Sparus Aurata, Dicentrarchus Labrax, Tonnus Thynnus, Thunnus Alalunga, Xiphaias Gladius, Pagellus Erythrinnus, Engraulis Encrasicholus, Belone Belone, Solea Solea, Merluccius Merluccius, Mullus Surmuletus) were analyzed through HPGe gamma spectrometry. The evaluation of dose levels and lifetime cancer risks for adult members of the population due to the fishes ingestion was also performed. Results: The specific activity of 40K was investigated and its mean value was found to be: (157 ± 17) for Sardina Pilchardus, (138 ± 14) for Mugil Cephalus, (118 ± 13) for Scomber Scombrus, (128 ± 14) for Sparus Aurata, (146 ± 17) for Dicentrarchus Labrax, (93 ± 11) for Tonnus Thynnus, (137 ± 15) for Thunnus Alalunga, (98 ± 10) for Xiphaias Gladius, (105 ± 12) for Pagellus Erythrinnus, (132 ± 14) for Engraulis Encrasicholus, (113 ± 12) for Belone Belone, (34 ± 5) for Solea Solea, (76 ± 9) for Merluccius Merluccius and (96 ± 11) for Mullus Surmuletus, respectively. Conclusions: The committed effective dose and the lifetime cancer risks for adult members of the population due to the consumption of the investigated samples are lower than the average world value, the maximum acceptable level and the allowed range, respectively. It can then be concluded that the Mediterranean sea fishes consumed in the study area pose no significant health risks to the population from a radiological point of view.

Reconstructing discards profiles of unreported catches

In Portugal it has been estimated that unreported catches represent one third of total catches. Herein, information on landings and total unreported catches (discards) by commercial métier were disaggregated into high taxonomic detail using published scientific studies. Fish accounted for 93.5% (115493 t) of overall unreported catches per year, followed by cephalopods (2345 t, 1.9%) and crustaceans (1754 t, 1.4%). Sharks accounted for 1.3% of total unreported catches in weight (1638 t/y). Unreported taxa consisted mostly of the commercial landed fish species: Scomber colias, Boops boops, Trachurus picturatus, T. trachurus, Merluccius merluccius, Sardina pilchardus, Liza aurata and Micromesistius poutassou, which together accounted for 70% of the unreported discarded catches. The number of unreported/discarded species was highest in artisanal fisheries, followed by trawl and purse seine. In artisanal fisheries, L. aurata, S. colias, S. pilchardus, Trachinus draco and B. boops accounted for 76.4% of the unreported discards. B. boops, S. colias and S. pilchardus were also among the most discarded purse seine species, together with Belone belone accounting for 79% of the unreported catches. In trawl fisheries, T. picturatus (16%), M. merluccius (13%), S. colias (13%) and M. poutassou (13%) accounted for 55% of the trawl discarded unreported catches. The discarded species that most contribute to overall unreported catches are those that are most frequently landed and that most contribute to overall landings in weight.

Metazoan parasite fauna of migrating common garfish, Belone belone (L.), in the Baltic Sea

A total of 35 common garfish,Belone belone(Linnaeus, 1761), were studied for metazoan parasites on their spawning grounds in the western Baltic Sea. Nine parasite species were found, and six new locality records could be established for German coastal waters (Axine belones, Monogenea;Proteocephalussp., Cestoda;Anisakis simplex(s.s.),Contracaecum rudolphiiA andHysterothylacium aduncum, Nematoda;Echinorhynchus gadi, Acanthocephala). For the first time, the marine ectoparasite A.beloneswas recorded from the gills of garfish inside the Baltic Sea, indicating its ability to survive the spawning migration as well as the brackish water conditions at its reproduction grounds. This is alike the endohelminthA.simplex(s.s.), that was identified by molecular analyses of the internal transcribed spacer (ITS-1, 5.8S, ITS-2) region. Almost all isolated metazoans were parasites commonly recorded from the northeast Atlantic Ocean and the North Sea. The lower number of typical generalist Baltic Sea parasites indicates the rapid migration of common garfish onto the spawning grounds, reducing the access and uptake of these species.