Search results for " MEDITERRANEAN SEA"

Citizen and scientists work together to monitor marine alien macrophytes

2018

The introduction of non-indigenous species (NIS) is an ongoing phenomenon which has been pointed out as a major threat to biodiversity at different levels (Wallentinus, Nyberg 2007, Katsanevakis et al. 2014, Vergés et al. 2016). NIS may in time become invasive (Invasive Alien Species “IAS”) and may cause biodiversity loss and ecosystem service changes (Brunel et al. 2013, Giakoumi 2014, Vergés et al. 2016). The Mediterranean Sea is an important hotspot for marine NIS (ca. 1,000 such species recorded to date, Zenetos et al. 2012, Galil et al. 2015, Verlaque et al. 2015). To reduce the risk of future IAS introduction and to better understand their invasive po- tential and spread dynamics, mon…

ROLE OF SICILY AND CIRCUM-SICILIAN ISLANDS AS RECIPIENT AND DONOR AREA FOR ALIEN MARINE MACROPHYTES IN THE CENTRAL MEDITERRANEAN SEA

2017

The spread of alien species is an ongoing phenomenon which is widely recognized as a major threat to biodiversity at all levels. The particularly high rate of alien introductions to the Mediterranean Sea has been mainly fuelled by the opening of the Suez Canal, by shipping, aquaculture and by a rising trend in seawater temperature. As far as marine macrophytes are concerned, a total of 134 species have been listed as possible aliens in the Mediterranean Sea. Among the possible pathways of introduction, shipping is considered the dominant vector of unintentional species introduction in coastal marine systems worldwide. Traversing the Strait of Sicily, the chief passageway from south to north…

Invasive Amphisteginids conquer the Sicily Channel and knock on the door of the Western Mediterranean Sea

2018

This study reports an updated overview of the current distribution and establishment status of the invasive species Amphistegina lobifera Larsen, 1979 and of other non-indigenous foraminifera in the Sicily Channel. The dispersal of marine non-indigenous species (NIS) by human activities is redefining the biogeography of the oceans and is one aspect of global change. Understanding the role of NIS in altering the structure of marine communities requires accurate information on their temporal occurrence, spatial distribution and effect on native ecosystems. However many NIS, particularly those belonging to small-sized unicellular taxa, such as benthic foraminifera, are largely unrecognized and…

Temporal and spatial variation of the algal community in a southern Mediterranean shallow system

2010

The algal community of a shallow system located in Western Sicily (Mediterranean Sea) has been investigated over 1 year in eight ponds (fredde). The spatio-temporal variation in total algal coverage, species richness and coverage in relation to environmental variables has been analysed. The algal community was very species-poor. A total of 50 taxa, mainly detached algae, were identified. A dominance of filamentous and foliose taxa was observed. Significant spatio-temporal differences in total algal coverage, species richness and coverage between the ponds of group A and those of group B were found. The separation into groups A and B was made a priori on the basis of different levels of prox…

Spreading of the alien seagrass Halophila stipulacea (Hydrocharitaceae) along the sicilian coast (western Mediterranean Sea)

2009

Halophila stipulacea (Forsskål) Ascherson is a tropical seagrass distributed along the western coasts of the Indian Ocean and in the Red Sea (den Hartog, 1977). This species was previously considered a paleomediterranean element, survived as a relict in the eastern Mediterranean Sea, but later on Por (1971) hypothesized that it was a Lessepsian immigrant entered the Mediterranean Sea after the opening of the Suez Canal (1869). H. stipulacea remained in the eastern Mediterranean for several decades (Lipkin, 1975), and only recently it spreads towards the western basin through Malta and the Ionian coast of Sicily (Lanfranco, 1970; Van der Velte and Den Hartog, 1989; Alongi et al., 1993). The …

Marine macrophytes: diversity and applications

2023

The research activity deals with several aspects of biology, systematics and ecology of marine macrophytes, with a special focus on macrophytes inhabiting the Mediterranean Sea. In particular, the research focuses on: 1) Marine alien macrophytes (e.g. Caulerpa, Asparagopsis, Halophila) and their interactions with autochthonous macrophytes, with particular attention to Marine Protected Areas. 2) Coralline red algae (Rhodoliths, Lithophyllum byssoides), characterized by a carbonate thallus, which form complex structures that increase the habitat biodiversity and are a key component in the cycle of carbonate budget. Thus, they are of high interest for conservation. 3) Brown algae belonging to …

Total phenolic content in brown algae from the Sicilian coast

2019

Phlorotannins are polyphenolic secondary metabolites found in almost all brown algae that function as defense against grazers, pathogens and epiphytes but are also involved in photoprotection mechanisms. These com- pounds, produced in the Golgi apparatus, are accumulated in cytoplasm, within vesicules called physodes, or bound to the cell wall. The concentration of phlorotannins differs within and between species, shows geograph- ical variations but may be also affected by abiotic or biotic factors. We present here an overview of the studies carried out on total phenolic content in brown algae collected along the north-western coast of Sicily. The aims of these studies were in particular a)…

Life on the edge: Adaptations of Posidonia oceanica to hypersaline conditions in a Mediterranean lagoon system

2023

Hypersaline stress is a major stressor in semi-enclosed coastal lagoons, affecting the distribution and survival of key foundation species. In this study, we investigated how Posidonia oceanica meadows responded physiologically and morphologically to different salinity concentrations both in-situ, across a natural saline gradient occurring inside the lagoon system, and in a mesocosm experiment. Leaf water relations, organic osmolytes, photosynthesis, respiration, Chlorophyll-a fluorescence, pigments content, and leaf growth were studied in P. oceanica from three different sites within the Stagnone of Marsala lagoon, as well as after exposing P. oceanica to a salinity level of 46 psu in a 30…

Brachidontes pharaonis (Bivalvia, Mytilidae), a lessepsian invader from a problematic species-complex

2012

The microcrustacean fauna of Sicily and the Central Mediterranean Sea area - Current knowledge and gaps to be filled

2006

The current knowledge of freshwater entomostracans from Sicily and some neighbouring central-Mediterranean countries is briefly reviewed. Data concerning different countries and different taxonomical groups are markedly inhomogeneous and often far from being representative of the real biota of the corresponding countries. This gap prevents a sound biogeographical analysis of the freshwater microcrustacean fauna of the area. The major gaps that have to be filled are highlighted and the need for more surveys and monitoring is emphasised.