Search results for "Oceano"
showing 10 items of 1626 documents
Determining stingray movement patterns in a wave-swept coastal zone using a blimp for continuous aerial video surveillance
2020
Stingrays play a key role in the regulation of nearshore ecosystems. However, their movement ecology in high-energy surf areas remains largely unknown due to the notorious difficulties in conducting research in these environments. Using a blimp as an aerial platform for video surveillance, we overcame some of the limitations of other tracking methods, such as the use of tags and drones. This novel technology offered near-continuous coverage to characterise the fine-scale movements of stingrays in a surf area in Kiama, Australia, without any invasive procedures. A total of 98 stingray tracks were recorded, providing 6 h 27 min of movement paths. The tracking data suggest that stingrays may u…
Interaction between bottlenose dolphins (Tursiops truncatus) and artisanal fisheries in the Valencia region (Spanish Mediterranean Sea)
2018
Abstract Coastal waters of the Valencia region are important habitats for bottlenose dolphins, but also important fishing grounds for artisanal fisheries. No studies have been carried out here to investigate the overlap and interactions between the fishing grounds and dolphin habitat. The present study aims to assess the potential occurrence of interactions between artisanal fisheries and bottlenose dolphins in these waters. Face to face interviews were conducted to investigate for the first time artisanal fishermen's perceptions of their interactions with bottlenose dolphins. A total of 131 fishermen (40.1% of the artisanal fleet for the Valencia region) participated of research. Among the…
Predicting common bottlenose dolphin habitat preference to dynamically adapt management measures from a Marine Spatial Planning perspective
2016
Abstract At the European Level, SACs (Special Areas of Conservation) are considered among the most reliable tools for increasing the efficiency of protective actions and to identify species vulnerability hotspots across spatial scales. Nevertheless, SACs may fail in their scope when design and management are not dynamically adapted to meet ecological principles. Knowledge of the spatial distribution of relevant key species, such as common bottlenose dolphin (Tursiops truncatus), is crucial in order to achieve the objective of the Habitat Directive (92/43/EEC), and is a fundamental step in the process of Marine Spatial Planning. From this perspective, new data and analysis are required to pr…
An updated overview of the marine alien and cryptogenic species from the Egadi Islands Marine Protected Area (Italy)
2016
An updated overview of the marine alien and cryptogenic species recorded in the Egadi Islands Marine Protected Area (Tyrrhenian Sea, Italy), based on relevant publications, grey literature and unpublished data, is presented and discussed. Altogether, 17 species (14 aliens and 3 cryptogenic) belonging to five taxa are present in the area: Rhodophyta (Antithamnionella elegans, Asparagopsis armata, Asparagopsis taxiformis, Bonnemaisonia hamifera, Botryocladia madagascariensis, Ceramium strobiliforme, Laurencia caduciramulosa, Lophocladia lallemandii, Neosiphonia harveyi, Womersleyella setacea), Chlorophyta (Caulerpa cylindracea and Caulerpa taxifolia), Mollusca (Aplysia dactylomela), Arthropod…
Changes in crustacean mesozooplankton and some environmental parameters in the Archipelago Sea (Northern Baltic) in 1976-1984
1990
Abstract The abundance of crustacean mesozooplankton was monitored by monthly sampling in the Archipelago Sea (Northern Baltic) during the years 1976-1984. Changes in the abundance of crustacean mesozooplankton species are compared with changes in water temperature, nutrient levels, chlorophyll-a, salinity and population densities of the Baltic herring (Clupea harengus membras L.). There was a rise of water temperature during the study period (about laC on average). The chlorophyll values were increasing, as were the nutrient levels in winter. Salinity was decreasing (on average 0.5‰ S). The biomass and abundance ofplanktivorous Baltic herring were increasing by about 30 and 50 per cent, re…
Sediment quality assessment using survival and embryo malformation tests in amphipod crustaceans: The Gulf of Riga, Baltic Sea AS case study
2017
Abstract The aim of this study was to assess the toxicity of bottom sediment and to estimate the potential effects of contaminated sediment on health of benthic organisms in the Gulf of Riga (eastern Baltic Sea). Two endpoints were used: survival rate (acute toxicity test) of five crustacean amphipod species and frequency of embryo malformation (samples were collected from the field) in the two species. Toxic resistance of living animals to sediment quality was measured as survival rate (%) at 25 study sites from 2010–2012. Significant differences in the toxic resistance between species were found: 80–100% for Monoporeia affinis, 70–95% for Corophium volutator, 38–88% for Pontogammarus robu…
Impact of harvesting cleaner fish for salmonid aquaculture assessed from replicated coastal marine protected areas
2017
Wrasse (Labridae) fisheries have increased markedly in Norway since 2010. Wrasse are being used as cleaner fish in salmonid aquaculture to control sea-lice infestations. However, fundamental knowledge on the demography and abundance of the targeted wrasse populations in Norwegian waters is lacking, and the consequences of harvesting at the current intensity have not been assessed. Here, we compared catch per unit effort (CPUE), size, age and sex ratio of goldsinny wrasse (Ctenolabrus rupestris) and corkwing wrasse (Symphodus melops) between marine protected areas (MPAs) and control areas open for fishing at four localities on the Skagerrak coast in Southern Norway. The CPUE of goldsinny lar…
Epibiontes en juveniles de tortugas carey Eretmochelys imbricata varadas en la costa del Departamento de Rocha, Uruguay
2016
The hawksbill turtle (Eretmochelys imbricata) is the most threatened sea turtle species in the world. An important aspect of the biology of sea turtles is the study of colonizing fauna, i.e., their epibiota. The aim of this study is a taxonomic determination on the epibiota found on 4 hawksbills turtles stranded in 2009 and 2011 on the coast of Rocha Department, Uruguay. The epibiota was composed by algae from the class Phaeophyceae (Sphacelaria sp. and Hincksia mitchelliae) and invertebrates from the classes Cirripedia (Platylepas hexastylos, Chelonibia testudinaria and Amphibalanus improvisus) and Hirudinea (Ozobranchus margoi), with greater predominance of P. hexastylos cirripeds (n= 365…
Like night and day: Reversals of thermal gradients across ghost crab burrows and their implications for thermal ecology
2018
Abstract Ghost crabs, Ocypode cordimanus, inhabit relatively hostile environments subject to thermal fluctuations, including both diurnal and seasonal cycles. For many ectotherms, including ghost crabs, a major challenge is to remain cool during hot daytime temperatures. This can be achieved by adopting a fossorial lifestyle, taking advantage of thermal refuge afforded by burrows of sufficient depth. Another consideration, often overlooked, is the potential advantage associated with ready access to a thermal energy source (a “charging station”) when surface temperatures are cooler. Being able to rapidly elevate body temperature during cool periods would enhance the crab's ability to maintai…
Carbon dynamics modelization and biological community sensitivity to temperature in an oligotrophic freshwater Antarctic lake
2016
Lake Limnopolar, located in one of the areas on Earth experiencing the strongest local warming, has been studied as a maritime Antarctic lake model by the Limnopolar Research Team during the last decade. Data collected during this period revealed the existence of an important meteorological interannual variability in the area of Byers Peninsula. With the aim of increasing the knowledge of this ecosystem and its sensibility to climate change as a model ecosystem, as well as to calibrate the extent of the interannual variability, a carbon flow model was developed partly describing its microbial food web. This preliminary model aims to describe part of the carbon dynamics, especially for bacte…