Biomasa y distribución del calamar gigante (Dosidicus gigas) en el mar peruano aplicando el método hidroacústico: 1999 - verano 2015.

La biomasa y distribución espacial del calamar gigante o pota (Dosidicus gigas) estimada mediante el método hidroacústico fue variable entre 1999 y 2015. La biomasa promedio en las estaciones de verano fluctuó entre 500.000 y 800.000 toneladas (t) a excepción del 2004 y 2005 cuando se estimaron las mayores abundancias con 1,7 millones de t y 1,6 millones de t, respectivamente. Las menores abundancias en verano, correspondieron a los años 2000, 2013 y 2014 con alrededor de 100.000 t. Durante la primavera, las mayores abundancias se registraron en el 2001 (863.000 t) y 2002 (879.000 t). En invierno, las biomasas fluctuaron entre 4.000 t (2010) y 560.000 t (2001). La variabilidad de la distribución espacial de la pota estuvo asociada a parámetros oceanográficos, influenciada principalmente por el frente oceánico y las masas de Aguas Subtropicales Superficiales (ASS); así como a isotermas de 18 °C a 25 °C e isohalinas de 34,8 ups a 35,5 ups.

Monitoring of macro- and microlitter in the Venice lagoon and coastal area

Marine litter and plastics are a significant and growing marine contaminant that has become a global problem. Macrolitter is subject to fragmentation and degradation due to physical, chemical and biological processes, leading to the formation of micro-litter, the so-called microplastics. The purpose of this research is to assess marine litter pollution by using remote sensing tools to identify areas of macrolitter accumulation and to evaluate the concentrations of microplastics in different environmental matrices: water, sediment and biota (i.e. mussels and fish) and to contribute to the European project MAELSTROM (Smart technology for MArinE Litter SusTainable RemOval and Management). The aim is to monitor the presence of macro- and microlitter at two sites of the Venice coastal area: an abandoned mussel farm at sea and a lagoon site near the artificial Island of Sacca Fisola; The results showed that both study areas are characterised by high amounts of marine litter, but the type of observed litter is different. In fact, in the mussel farm area, most of the litter is linked to aquaculture activities (ropes, nets, mooring blocks and floating buoys). In the Venice lagoon site, the litter comes more from urban activities and from the city of Venice (car tyres, crates, wrecks, etc.). Microplastics is present in both sites and in all the analysed matrices. Generally, higher microplastics concentrations were found at Sacca Fisola (i.e., in surface waters, mussels and fish). Moreover, some differences were also observed in shapes and colours comparing the two sites. At Sacca Fisola, white irregular fragments predominate in water samples, blue filaments in sediment and mussels, and transparent irregular fragments in fish. At the Mussel Farm, blue filaments predominate in water, sediment and mussels, while flat black fragments predominate in fish. These differences are related to the different types of macrolitter that characterised the two areas.

Water jet based autonomous surface vehicle for coastal waters operations

This paper presents the design of low cost, small autonomous surface vehicle for missions in the coastal waters and specifically for the challenging surf zone. The main objective of the vehicle design described in this paper is to address both the capability of operation at sea in relative challenging conditions and maintain a very low set of operational requirements (ease of deployment). This vehicle provides a first step towards being able to perform general purpose missions (such as data gathering or patrolling) and to at least in a relatively short distances to be able to be used in rescue operations (with very low handling requirements) such as carrying support to humans on the water. The USV is based on a commercially available fiber glass hull, it uses a directional waterjet powered by an electrical brushless motor for propulsion, thus without any protruding propeller reducing danger in rescue operations. Its small dimensions (1.5 m length) and weight allow versatility and ease of deployment. The vehicle design is described in this paper both from a hardware and software point of view. A characterization of the vehicle in terms of energy consumption and performance is provided both from test tank and operational scenario tests. An example application in search and rescue is also presented and discussed with the integration of this vehicle in the European ICARUS (7th framework) research project addressing the development and integration of robotic tools for large scale search and rescue operations.

Pb-210 and composition data of near-surface sediments and interstitial waters evidencing anthropogenic inputs in Amazon River mouth, Macapa, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Pigment concentrations and biomass of phytoplankton and of its dominant species in surface Black Sea waters in 1998-2000

Data on chlorophyll a concentration and species composition and biomass of phytoplankton have been collected for two years continues monitoring in the central part and the slope zone of the Black Sea. Seasonal dynamics of chlorophyll a concentration correspond to U-type. It is characterized by low values in summer, high values in autumn, which are going to winter-spring bloom of phytoplankton. Oscillations of mean values of chlorophyll concentrations are equal to 3-4 in the central part and 2 - in the slope zone. In the autumn-winter-spring period high values of phytoplankton biomass are related to typical blooming diatom algae in the first year and other taxons - in the second year. Relationship between relative content of phaeopigment and chlorophyll concentration has been determined for the central western part of the sea. Seasonal dynamics of carbon/chlorophyll a ratio has been shown. For both regions mean values of this ratio were equal to ~20 in autumn-winter-spring time and 40-50 - in summer time.

(Table 1) Near surface water chemistry of south Patagonian waters during spring and winter

Both the biomass of autotrophic dinoflagellates and its contribution to total chlorophyll were found to increase significantly with seawater temperature and the level of stratification in southern Patagonian waters during spring and winter. The highest peak of biomass corresponded to a single species, Prorocentrum minimum (Pavillard) Schiller, and was detected in middle shelf waters, coinciding with the primary productivity and CO2 uptake maxima reported for the area under spring conditions.