Search results for " marine"

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…

Cetacean presence and distribution in the central Mediterranean Sea and potential risks deriving from plastic pollution

2021

Abstract The Sardinian and Sicilian Channels are considered hotspots of biodiversity and key ecological passages between Mediterranean sub-basins, but with significant knowledge gaps about marine mammal presence and potential threats they face. Using data collected between 2013 and 2019 along fixed transects, inter and intra-annual cetacean index of abundance was assessed. Habitat suitability, seasonal hot spots, and risk exposure for plastic were performed using the Kernel analysis and the Biomod2 R-package. 661 sightings of 8 cetacean species were recorded, with bottlenose and striped dolphins as the most sighted species. The north-eastern pelagic sector, the coastal waters and areas near…

Impacts of marine aquaculture at large spatial scales: evidences from n and p catchment loading and phytoplankton biomass

2011

International audience; While several studies point at off-shore aquaculture as a possible source of impacts on the local marine environment, very few have analysed its effects at large scales such as at the bay, gulf or basin levels. Similar analyses are hampered by the multiple sources of disturbance that may concomitantly affect a given area. The present paper addresses these issues taking the Gulf of Castellammare (Southern Tyrrhenian Sea) as an example. Nitrogen (N) and phosphorous (P) loads were calculated for the period 1970-2007, and compared to chlorophyll-a concentration as measured inside and outside the Gulf over the same period. Results indicate that N and P catchment loading h…

Is Citizen Science a valid tool for monitoring alien species in Marine Protected Areas?

2020

We report on our experience of NIS monitoring within the Egadi Islands MPA and at Pianosa Island National Park of Tuscan Archipelago through Citizen Science projects The Projects Caea cdacea Egadi Islands and Aliens in the Sea allowed to gather useful information on the distribution and colonisation strategies of NIS and cryptogenic species within the Egadi Islands MPA The project Percorsi nel bluBlue Paths allowed to register the first record of two cryptogenic species, Aa dacea Rang, and Pec gbbe H Milne Edwards, , at Pianosa Island As in MPAs the protection does not hinder the introduction and spreading of NIS, we expect they are likely to continue to arrive and expand in the absence of …

Modeling Macroalgal Forest Distribution at Mediterranean Scale: Present Status, Drivers of Changes and Insights for Conservation and Management

2020

Macroalgal forests are one of the most productive and valuable marine ecosystems, but yet strongly exposed to fragmentation and loss. Detailed large-scale information on their distribution is largely lacking, hindering conservation initiatives. In this study, a systematic effort to combine spatial data on Cystoseira C. Agardh canopies (Fucales, Phaeophyta) was carried out to develop a Habitat Suitability Model (HSM) at Mediterranean scale, providing critical tools to improve site prioritization for their management, restoration and protection. A georeferenced database on the occurrence of 20 Cystoseira species was produced collecting all the available information from published and grey lit…

Integrating natural capital assessment and marine spatial planning: A case study in the Mediterranean sea

2017

Abstract Marine and coastal ecosystems are among the most productive environments in the world and their stocks of natural capital offer a bundle of vital ecosystem services. Anthropogenic pressure seriously threatens health and long-term sustainability of marine environments. For these reasons, integrated approaches capable of combining ecological and socio-economic aspects are needed to achieve nature conservation and sustainability targets. In this study, the value of natural capital of the Egadi Islands Marine Protected Area (EI-MPA) was assessed through a biophysical and trophodynamic environmental accounting model. The emergy value of both autotrophic and heterotrophic natural capital…

The trophic transfer of persistent pollutants (HCB, DDTs, PCBs) within polar marine food webs.

2017

Biomagnification (increase in contaminant concentrations at successively higher levels of trophic web), is a process that can transversally impair biodiversity and human health. Most research shows that biomagnification should be higher at poles with northern sites having a major tendency to biomagnify Persistent Organic Pollutants (POPs) through their marine food webs. We investigated the biomagnification degree into two marine trophic webs combining carbon and nitrogen stable isotopes and POP analyses. We showed that the Antarctic trophic web was more depleted than the sub-Arctic one and the differences highlighted for the basal part could explain the difference in length between them. Co…

Short-term exposure to concurrent biotic and abiotic stressors may impair farmed molluscs performance

2022

Global warming, through increasing temperatures, may facilitate the spread and proliferation of outbreak-forming species which may find favourable substrate conditions on artificial aquaculture structures. The presence of stinging organisms (cnidarian hydroids) in the facilities fouling community are a source of pollution that can cause critical problems when in-situ underwater cleaning processes are performed. Multiple stressor experiments were carried out to investigate the cumulative effect on farmed mussels' functional traits when exposed to realistic stressful conditions, including presence of harmful cnidarian cells and environmental conditions of increasing temperature and short-term…

Functional traits, mechanistic bioenergetics and microclimatic downscaling of marine ectotherms

2014

Genetic structure in the Mediterranean seagrass Posidonia oceanica: disentangling past vicariance events from contemporary patterns of gene flow

2010

The Mediterranean Sea is a two-basin system, with the boundary zone restricted to the Strait of Sicily and the narrow Strait of Messina. Two main population groups are recognized in the Mediterranean endemic seagrass Posidonia oceanica, corresponding to the Western and the Eastern basins. To address the nature of the East-West cleavage in P. oceanica, the main aims of this study were: (i) to define the genetic structure within the potential contact zone (i.e. the Strait of Sicily) and clarify the extent of gene flow between the two population groups, and (ii) to investigate the role of present water circulation patterns vs. past evolutionary events on the observed genetic pattern. To achiev…