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A quantitative analysis of water masses in the Brazil‐Malvinas Confluence zone is performed with a least squares multiple tracer analysis using data from the confluence winter 1989 cruise. The purpose is to find the mixture of source water types that best describes the composition of a given water sample. This method is valuable in regions involving strong mixing among various source water types, as is the Brazil‐Malvinas Confluence zone. Seven main core layers are identified in this region, and all are retained for the analysis: the Thermocline Water (TW), the Subantarctic Surface Water (SASW), the Antarctic Intermediate Water (AAIW), the Upper Circumpolar Deep Water (UCDW), the North Atlantic Deep Water (NADW), the Lower Circumpolar Deep Water (LCDW), and the Weddell Sea Deep Water (WSDW). Tracers selected are temperature, salinity, dissolved nutrients, and oxygen. The results show the proportion of each source water type along four east‐west sections (35.4°S, 36.5°S, 37.9°S, 39°S). They are accurate to within 20% for all sources. The solution presents evidence of local recirculation of AAIW largely influenced by the two strong currents, Brazil and Malvinas. Southward TW and NADW separate from the coast, NADW turning eastward at a higher latitude than TW.

Purpose: In Algeria, the Ministry of Fisheries and Halieutic Resources has designed a strategic plan for the development of marine aquaculture for the years 2015–2025, which aims at expanding the annual production of Mediterranean mussel from less than 150 metric tonnes year−1 in 2013 to 7600 metric tonnes year−1 in 2025. We used Life Cycle Assessment (LCA) for evaluating the environmental impact of suspended mussel culture in Algeria and suggest management practices which could reduce it. Methods: In order to estimate the current and perspective impact of this industry, we (1) applied LCA to one of the few farms currently operating in Algeria and (2) investigated two management scenarios for the farms to be established in the future in the same coastal area. The first scenario (Comp_S) represents the continuity with the current situation, in which each farm is competing with the other ones and is therefore managing the production cycle independently. In the second scenario (Coop_S), mussel farms are grouped in an aquaculture management area and shared the same facilities for post-processing harvested mussels before sending them to the market. The midpoint-based CML-IA method baseline 2000 V 3.01 was employed using SimaPro software. Furthermore, we carried out a Monte Carlo simulation, in order to assess the uncertainty in the results. Results and discussion: The analysis focused on impact categories related to acidification and global warming potential. We took into account the energy consumptions (electricity and vessel fuel), the rearing infrastructure, including longlines, and a building for stabling, grading, and packing the mussel. Electricity contributes with 38.1 and 31.8 % respectively to global warming potential (GWP) and acidification, while fuel consumption contributes with 19.5 % to GWP and 31.8 % to acidification. Results of this work are compared with other LCA studies recently carried out in France (Aubin and Fontaine 2014) and in Spain (Iribarren et al. 2010c). Conclusions: The LCA results show that important reductions in environmental impacts could be attained if the mussel farming activity would be operated according to the cooperative scenario here proposed. In this case, the environmental benefits will be a reduction of 3150 MJ and 156 kg CO2 eq per metric tonne of mussel produced, compared with the alternative scenario. The results of this study suggest that LCA should be applied to the seafood production sector in Algeria, in order to identify best management practices

A large scale study of trace metal contamination (Hg, Cd, Pb and Ni) by means of caged mussels Mytilus galloprovincialis was undertaken along the coastal waters of the Western Mediterranean Sea within the context of the MYTILOS project. Individual mussels from an homogeneous population (shell size 50 ± 5 mm) obtained from an aquaculture farm were consecutively caged and deployed at 123 sites located in the Alborán, North-Western, South-Western and Tyrrhenian sub-basins for 12 weeks (April-July) in 2004, 2005 and 2006. After cage recoveries, both the metal content in the whole mussel tissue and the allometric parameters were measured. Statistical analysis of the datasets showed significant differences in concentrations between sub-basins for some metals and mussel condition index (CI). Linear regression models coupled to the CI were revisited for the data adjustment of certain trace metals (Hg, Cd and Ni), and four level categories were statistically derived to facilitate interregional comparison. Seawater masses surrounding coastal areas impacted by run-off from land mineralised coasts and industrial activities displayed the highest concentration ranges (Hg: 0.15-0.31 mg kg(-1) dw; Cd: 1.97-2.11; Ni: 2.18-3.20 and Pb: 3.1-3.8), although the levels obtained in most of the sites fitted within moderate or low categories, and they could be considered as baseline concentrations. However, few sites considered little-influenced by human activities, at present, showed high concentrations of Cd, Ni and Pb, which constitute new areas of concern. Overall, the use of active biomonitoring (ABM) approach allowed to investigate trace metal contamination in order to support policy makers in establishing regional strategies (particularly, with regard to the European Marine Strategy Directive).

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