Search results for "Ocean"
showing 10 items of 2919 documents
Performance Assessment of Posidonia oceanica (L.) Delile Restoration Experiment on Dead matte Twelve Years after Planting—Structural and Functional M…
2021
Following the restoration of natural conditions by reducing human pressures, reforestation is currently considered a possible option to accelerate the recovery of seagrass habitats. Long-term monitoring programs theoretically represent an ideal solution to assess whether a reforestation plan has produced the desired results. Here, we report on the performance of a 20 m2 patch of Posidonia oceanica transplanted on dead matte twelve years after transplantation in the Gulf of Palermo, northwestern Sicily. Photo mosaic performed in the area allowed us to detect 23 transplanted patches of both regular and irregular shape, ranging from 0.1 to 2.7 m2 and an overall surface close to 19 m2. Meadow d…
Drawing the Line at Neglected Marine Ecosystems: Ecology of Vermetid Reefs in a Changing Ocean
2016
Vermetid mollusks form reefs that protect coasts from erosion, regulate sediment transport, serve as carbon sinks, and provide habitat for many fish and invertebrates. This biogenic habitat is found in tropical, sub-tropical, and warmtemperate coastal areas, such as Bermuda, oceanic islands in Brazil, and Hawaii, several locations within the Caribbean and the Mediterranean. These reefs are functionally similar to tropical coral fringing reefs but are built by gregarious vermetid gastropods cemented by a crustose coralline algal species, which probably triggers their settlement. Some descriptive studies in different regions worldwide and comparisons among tropical and Mediterranean reefs con…
Marine caves of the Southern Tyrrhenian Sea: a First Census of Benthic Biodiversity
2017
This is the first paper documenting research on a selection of marine caves located along the coast of Capo Milazzo in the southern Tyrrhenian Sea. Three submarine and one semi-submerged caves were surveyed and sampled using underwater photo sampling. Surveys have only taken into account the sessile species belonging to the main taxa: Porifera, Anthozoa, Bryozoa and Polychaeta. Diversity indices and abundances were calculated for three sections within each explored cave: the Entrance Zone, Intermediate Zone and Bottom Zone. The richest group was Porifera with 21 taxa, followed by cnidarians, (Anthozoa), with 8 taxa, Polychaeta (5 taxa), and Bryozoa (5 taxa). Among Porifera, the presence of …
Mapping the potential for offshore aquaculture of salmonids in the Yellow Sea
2022
AbstractMariculture has been one of the fastest-growing global food production sectors over the past three decades. With the congestion of space and deterioration of the environment in coastal regions, offshore aquaculture has gained increasing attention. Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) are two important aquaculture species and contribute to 6.1% of world aquaculture production of finfish. In the present study, we established species distribution models (SDMs) to identify the potential areas for offshore aquaculture of these two cold-water fish species considering the mesoscale spatio-temporal thermal heterogeneity of the Yellow Sea. The values of the a…
The trophic role of the macrophyte Cymodocea nodosa (Ucria) Asch. in a Mediterranean saltworks: Evidence from carbon and nitrogen stable isotope rati…
2002
A multiple stable isotope analysis (δ13C and δ15N) was used to determine the trophic role of the seagrass Cymodocea nodosa (Ucria) Asch. for consumers in a Mediterranean saltworks. Stable carbon and nitrogen isotope ratios performed on primary producers and consumers in February and July 1999 showed that C. nodosa is not a direct dietary source via grazing. No animal presented carbon values as enriched as the seagrass (-7.8‰). The trophic role of Cymodocea occurs through the detritus route via SOM. Sedimentary organic matter (SOM) (δ13C = -16.5‰) seems to be a mixture of particulate organic matter (δ13C = -19.0‰), algae (δ13C = -18.6‰) and seagrass detritus (δ13C = -7.7‰). The results of a …
Assessment of the ecological status of transitional waters in Sicily (Italy): first characterisation and classification according to a multiparametri…
2010
A 1-year cycle of observations was performed in four Sicilian transitional water systems (Oliveri-Tindari, Cape Peloro, Vendicari and Marsala) to characterise their ecological status. A panel of variables among which trophic and microbial (enzyme activities, abundance of hetetrophic bacteria and of bacterial pollution indicators) parameters, were selected. Particulate organic carbon (POC) and nitrogen (PON) and chlorophyll-. a (Chl-. a) contents defined the trophic state, while microbial hydrolysis rates and abundance gave insights on microbial community efficiency in organic matter transformation and on allochthonous inputs. To classify the trophic state of examined waters, the synthetic t…
Scuba diver behaviour and its effects on the biota of a Mediterranean marine protected area
2009
The effects of diving activity in different Mediterranean subtidal habitats are scarcely known. This study evaluates diver behaviour (for example time spent in each habitat), use (contacts made with the substrate) and immediate effects of diver contact on benthic species in a marine protected area (MPA) in Sicily. Over a two-year period, intentions of 105 divers were observed within seven subtidal habitats: algae on horizontal substrate, algae on vertical substrate, Posidonia oceanica, encrusted walls, caves, sand and pebbles. Divers selected a habitat in proportion to its availability along the scuba trail. On average, each diver made 2.52 contacts every seven minutes, and no differences w…
Detection and mapping of Posidonia oceanica dead matte by high-resolution acoustic imaging
2009
A high-resolution echosounder was used to acquire seismo-acoustic records of P. oceanica dead matte patches in the Gulf of Palermo. Seismo-acoustic profiling enabled detection of dead matte structures that are invisible to visual inspection, being hidden by variable layers of sandy sediment. The thickness of the dead matte measured reaches a maximum of 2.2 m. The mean volume of the matte per unit area of seabed surface (MEIx) varies from 0.2 to 2.2 m 3 /m 2 , with an average value of 1.6 m 3 /m 2 and a total volume estimated at 73,000 m 3 . From literature data and from the volume of dead matte calculated in the present work we estimated that total carbon accumulated in the matte is about 2…
ROLE OF BEHAVIOUR IN MARINE ORGANISMS: POTENTIAL EFFECTS UNDER FUTURE OCEAN CONDITIONS.
2021
Over the last 250 years, the intensive burning of fossil fuels along with industrial processes and land uses (e.g. clearing forests and agriculture) has contributed to an increase in atmospheric CO2 from approximately 280 to 410 ppm, with a further increase (from 730 to 1020 ppm) projected by the end of this century. About 30% of the anthropogenic CO2 has been absorbed by the ocean, with a consequent decrease of the ocean’s surface pH causing a phenomenon better known as Ocean Acidification (OA). The average pH of the surface ocean has declined from 8.2 by 0.1 units since pre-industrial times as a result of CO2 emissions and a further reduction of 0.3–0.5 pH units is expected to occur by th…
Dynamic Energy Budget model parameter estimation for the bivalve Mytilus californianus: Application of the covariation method
2014
Dynamic Energy Budget (DEB) models serve as a powerful tool for describing the flow of energy through organisms from assimilation of food to utilization for maintenance, growth and reproduction. The DEB theory has been successfully applied to several bivalve species to compare bioenergetic and physiological strategies for the utilization of energy. In particular, mussels within the Mytilus edulis complex (M. edulis, M. galloprovincialis, and M. trossulus) have been the focus of many studies due to their economic and ecological importance, and their worldwide distribution. However, DEB parameter values have never been estimated for Mytilus californianus, a species that is an ecological domin…