Search results for " Fish"
showing 10 items of 1414 documents
Sizing up the role of predators on Mullus barbatus populations in Mediterranean trawl and no-trawl areas
2019
Abstract Fishing leads to drastic changes in ecosystems with a net loss of predatory biomass. This issue has been evidenced from historical ecological studies and from the evaluation of the effects of effective and large marine protected areas. In two fishery reserves off the northern Sicily coast the red mullet Mullus barbatus underwent an impressive biomass increment and a few piscivores fish species recovered after a trawl ban. The red mullet, more than 20% of all demersal fish in the untrawled areas, represented a huge food resource to its potential predators. By contrasting two trawled and two untrawled gulfs we figured out predator - prey relationships through the use of a combined ap…
Cumulative climatic stressors strangles marine aquaculture: Ancillary effects of COVID 19 on Spanish mariculture
2021
9 pages, 8 figures
Experimental rearing of the sea urchinParacentrotus lividusfed with discards of the lettuceLactuca sativain a sea-based system
2017
Small-sized specimens (test diameter: 16.64 ± 0.93 mm, mean ± SE) of the sea urchin Paracentrotus lividus were fed with fresh discards of the lettuce Lactuca sativa during a 24-week experiment in a sea-based system. At the end of the experiment, stock survival was high (88.8 ± 6.6%). Sea urchin test diameter and total weight grew by 35% and 56%, respectively, while gonad somatic index, after an initial decrease, increased by 3.2%. Moreover, more than 90% of specimens achieved the gonad colour that the market demands. These results support the exploitation of L. sativa as the main ingredient in a manufactured diet for echinoculture of P. lividus. Employing diets formulated with discard ingre…
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 …
Functional trait-based layers - an aquaculture siting tool for the Mediterranean Sea
2021
Abstract Aquaculture, the current fastest-growing food sector, is one of the major opportunities that could be reaped to cope with the increased demand for proteins from the sea and simultaneously generate economic growth while ensuring sustainable use of natural resources. The number of tools and approaches suggested to promote the selection of suitable areas - focusing mostly on the management of potential conflicting uses at sea - is rapidly increasing. However, to date, there is a lack of information regarding spatial planning according to a trait-based approach encompassing the functional and biological data of farmed species; a gap that may lead to selecting unsuitable areas for farmi…
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…
Leaf vs. epiphyte nitrogen uptake in a nutrient enriched Mediterranean seagrass (Posidonia oceanica) meadow
2012
Abstract In situ nitrogen uptake by leaves and epiphytes was studied in a Mediterranean seagrass (Posidonia oceanica) meadow impacted from a fish farm and a pristine meadow, using 15NH4 and 15NO3 as tracers. In the impacted meadow both leaves and epiphytes yielded higher N concentrations and showed higher specific N uptake, suggesting a linkage between N uptake and its accumulation. Epiphytes took up N faster than leaves in relation to their corresponding biomass, but when assessed per unit area, N uptake was higher in leaves. Leaf N uptake was negatively correlated with epiphyte N uptake. With increasing epiphyte load on leaves, N leaf uptake decreased while N epiphyte uptake increased, in…
Effect of boat noise on the behaviour of bluefin tuna Thunnus thynnus in the Mediterranean Sea
2007
The effect of boat noise on the behaviour of bluefin tuna Thunnus thynnus was investi- gated in the Egadi Islands, Sicily, during spring 2005 using a fixed tuna trap set near shipping routes. Tuna behaviour was observed when exposed to both natural ambient sound and sound generated by hydrofoil passenger ferries, small boats and large car ferries. Acoustical and behavioural analyses were conducted with and without extraneous sound to define a list of behavioural categories. Each vessel produced different engine sounds with regard to their composition and bandwidth, and all were distinctly different from ambient sound levels. In the absence of boat noise, tuna assumed a con- centrated coordi…
Differential response of benthic microbes and meiofauna to fish-farm disturbance in coastal sediments
2001
Bacterial and meiofaunal abundance and biomass and their response to the disturbance induced by fish-farm biodeposition were investigated from March to October 1997 on a monthly basis at two stations of the Gaeta Gulf (Tyrrhenian Sea, Mediterranean Sea). The biopolymeric fraction of the organic matter was characterized by high concentrations which was similar at both fish-farming-impacted and control stations. Similarly, bacteria accounted for a small fraction of the biopolymeric organic carbon (<1%), while the contribution due to auto-fluorescent cell biomass (i.e. prokaryotic and eukaryotic cells displaying auto-fluorescence) to the total biopolymeric carbon was quantitatively negligible …
Impact of COVID-19 on aquaculture sector in Malaysia: Findings from the first national survey
2021
Abstract Malaysian aquaculture sector consists of 391,000 t of cultivated organisms produced per year with an economic value for over USD 700 million as estimated in 2019. The COVID-19 pandemic caused a large global human pandemic and it is currently ongoing, affecting profoundly Malaysian aquaculture, which is vital for seafood provision and security assurance. Thus, to increase our understanding about how the pandemic affects aquaculture sectors is crucial to design possible management measures both at local and national level. To do it, we designed a survey, starting in May 2020, consisting of 25 online questions to collect information about the impact of COVID-19 on the aquaculture sect…