Search results for "algae"
showing 10 items of 403 documents
Horizontal and vertical food web structure drives trace element trophic transfer in Terra Nova Bay, Antarctica
2019
Abstract Despite a vast amount of literature has focused on trace element (TE) contamination in Antarctica during the last decades, the assessment of the main pathways driving TE transfer to the biota is still an overlooked issue. This limits the ability to predict how variations in sea-ice dynamics and productivity due to climate change will affect TE allocation in the food web. Here, food web structure of Tethys Bay (Terra Nova Bay, Ross Sea, Antarctica) was first characterised by analysing carbon and nitrogen stable isotopes (δ13C, δ15N) in organic matter sources (sediment and planktonic, benthic and sympagic primary producers) and consumers (zooplankton, benthic invertebrates, fish and …
Ocean acidification bends the mermaid's wineglass
2015
Ocean acidification lowers the saturation state of calcium carbonate, decreasing net calcification and compromising the skeletons of organisms such as corals, molluscs and algae. These calcified structures can protect organisms from predation and improve access to light, nutrients and dispersive currents. While some species (such as urchins, corals and mussels) survive with decreased calcification, they can suffer from inferior mechanical performance. Here, we used cantilever beam theory to test the hypothesis that decreased calcification would impair the mechanical performance of the green alga Acetabularia acetabulum along a CO 2 gradient created by volcanic seeps off Vulcano, Italy. Cal…
Polyculture as a tool to increase the economic income: a study case in the Gulf of Castellammare
2010
Polyculture is a practice involving integration between organisms of different trophic levels (i.e. fish with low-trophic-level organism like molluscs and/or algae). This paper, reporting on a field experiment carried out during 2004 in the Gulf of Castellammare (South Tyrrhenian), showed that mussels transplanted in areas under fish farm influence grew up better than mussels transplanted far from fish farm. Thus, results pointed out polyculture as a reliable tool for i) increasing local bivalve production, ii) obtaining the reduction of importation from other countries and iii) increasing the environmental sustainability of fish aquaculture.
Uptake and photoinduced degradation of phthalic acid esters (PAEs) in Ulva lactuca highlight its potential application in environmental bioremediation
2022
Abstract The bioaccumulation of phthalates was studied in fragments of Ulva lactuca exposed for a maximum of 31 days at different concentrations of a solution of six phthalic acid esters (PAEs). The algal matrix showed rapid uptake since the first sampling, which increased over the time of the experimental period, at the end of which seaweed’s bioaccumulation potential was also evaluated. After the uptake, the algal matrix was subjected to UV irradiation in order to verify the removal of the phthalates. PAEs with higher octanol–water partition coefficients (logKow) and molecular weights were preferentially uptaken by U. lactuca in all the exposure experiments. It was observed that both accu…
A century of research on micro-organisms from the inland waters of the largest mediterranean island
2022
The first studies on the micro-organisms inhabiting Sicilian inland waters date back to the middle of the XIX century. However, these were based on single samples and mainly addressed at compiling faunistic and floristic inventories. It was in the first decades of the XX century that the first methodical studies were performed, which focussed on assessing microbial diversity in saline and hypersaline inland waters. Studies on plankton dynamics in ponds and reservoirs of the island started at the beginning of the 1980s and, since the end of the 1990s, temporary waters have also been intensively sampled, especially as regards phytoplankton and micro-crustaceans. These intensified sampling eff…
Nest building in a Mediterranean wrasse (Symphodus ocellatus): are the algae used randomly chosen or actively selected?
2014
To increase their reproductive success, fish species have evolved various strategies, including both simple processes and more complex mechanisms that involve parental care by nest-building. In Symphodus ocellatus, a species that lives in rocky infralittoral zones of the Mediterranean Sea, during the reproductive period, the male builds a nest within a hole or crevice using fragments of algae and/or sand particles. Data on the nesting activity of wrasses are rare, and previous descriptions regarding the algal composition of nests have provided conflicting results. In this regard, it is unclear whether territorial males actively select algal species for nest construction or algal choice is r…
Thermal variance affects algal assemblage in rocky pools
2013
The intertidal rocky pools are habitats that, when disconnected from the sea, become highly stressful for sessile organisms such as algae. Algae experience wide changes of water temperature on short temporal scale (e. g. hour or lower) and their coverage and diversity are expected to depend on thermal variance of small water masses trapped at low tide. Here, we want to investigate the relationship between daily thermal variance and the composition, coverage and diversity of rocky pool’s algal community in Western Sicily (Southern MED). We chose 15 intertidal rocky pools and we deployed, in August 2012, thermo-loggers for two days to record temperature changes every 5-min (12 recordings per …
Influence of hydrothermal vents on phytobenthic communities in the Aeolian Islands (Tyrrhenian Sea): preliminary results
2010
Ocean acidification effects on stable isotope signatures and trophic interactions of polychaete consumers and organic matter sources at a CO2 shallow…
2015
Abstract Stable carbon and nitrogen isotope analysis (SIA) was used to examine trophic interactions in a naturally acidified shallow coastal CO2 area in the Mediterranean Sea. SIA was helpful to determine the potential effects of ocean acidification (OA) on the interactions of organic matter sources and polychaete consumers, which appear to be tolerant to high pCO2. Mesoherbivore consumers, represented by three polychaete species, Platynereis dumerilii (Audouin and Milne Edwards, 1834) (Nereididae), Polyophthalmus pictus (Dujardin, 1839) (Opheliidae) and Syllis prolifera Krohn, 1852 (Syllidae), are abundant in the low pH conditions of the CO2 vents. Samples of consumers and potential organi…