Search results for "MEDITERRANEAN SEA"

Lulwoana sp., a dark septate endophyte (DSE) in roots of Posidonia oceanica (L.) Delile seagrass

2014

Posidonia oceanica is the most common, widespread and important monocotyledon seagrass in the Mediterranean Basin, and hosts a large biodiversity of species, including microorganisms with key roles in the marine environment. In this study, we ascertain the presence of a fungal endophyte in the roots of P. oceanica growing on different substrata (rock, sand and matte) in two Sicilian marine meadows. Staining techniques on root fragments and sections, in combination with microscope observations, were used to visualise the fungal presence and determine the percentage of fungal colonisation (FC) in this tissue. In root fragments, statistical analysis of the FC showed a higher mean in roots anch…

Genetic population structure of Epinephelus marginatus (Pisces, Serranidae) revealed by two molecular markers

2006

In this paper, data are presented regarding the population structure of dusky grouper (Epinephelus marginatus) which was sampled in the Mediterranean Sea and Atlantic Ocean using two different molecular markers, ND2 RFLP and cytochrome b (cyt b) sequence analysis. The main objective of the study is to analyse the genetic variability of E. marginatus in the Mediterranean Sea to define how the biological characteristics of the species, such as the dispersal capability of pelagic larvae and the benthonic-sedentary life style, can affect the genetic population structure or maintaining the gene flow or determining genetic differences. Furthermore, we considered an Atlantic sample to establish th…

Alien macrophytes in the Mediterranean Sea: an overview

2019

The Mediterranean Sea, one of the most complex marine ecosystems, is inhabited by a rich and diverse biota which is disproportionate to its dimensions. Such high species richness makes the Mediterranean Sea a true hotspot of biodiversity. However, the Mediterranean Sea is amongst the most impacted regional sea areas, due to increasing levels of threats, mainly driven by human activities such as climate change and the introduction of non-indigenous species (NIS, i.e. organisms introduced outside of their natural, past or present, range and outside of their natural dispersal potential). NIS may in time become invasive (i.e. invasive alien species (IAS)) with severe impacts on biodiversity and…

ARE MARINE PROTECTED AREAS (MPAs) EFFECTIVE IN PROTECTING FROM INVASIVE SPECIES? THE CASE STUDY OF CAULERPA CYLINDRACEA SONDER (CAULERPALES, CHLOROPH…

2019

The main purpose of Marine Protected Areas (MPAs) is biodiversity conservation. The effects that invasive species have on MPAs, and vice versa, are still not completely known, even though their assessment is crucial for MPA management and conservation purposes. In this respect, monitoring plans are essential and the involvement of citizen scientists may be fundamental. Our experience of Caulerpa cylindracea Sonder 1845 monitoring within the Egadi Islands MPA highlighted that the alga is widespread within the MPA, mainly at Favignana Island, also threatening valuable habitats such as vermetid reef and coralligenous formations. Moreover, Favignana is the island of the Aegadian archipelago mos…

CAN HALOPHILA STIPULACEA OUTCOMPETE CYMODOCEA NODOSA? A CASE STUDY OF A MEDITERRANEAN SHALLOW WATER HABITAT

2022

The tropical seagrass Halophila stipulacea (Forsskål) Ascherson entered the Mediterranean Sea through the Suez Canal more than 100 years ago. In the coastal-marine ecosystems the spatial niche of H. stipulacea is often overlapped with that of native Mediterranean Sea seagrasses and therefore it might out-compete them. On the basis of previous observations, we monitored for one year a Southern Mediterranean shallow water habitat (North-Western Sicily Island, Italy, Southern Mediterranean Sea), where H. stipulacea co-occurred with the native seagrass Cymodocea nodosa (Ucria) Ascherson. In this paper we compare sites with (impacted sites) and without H. stipulacea (non-impacted sites) to analy…

Competition between algae and seagrasses: a Ruppia cirrhosa (Petagna) Grande bed in western Mediterranean Sea

2007

Human activities trigger change in marine landscape

2018

Biodiversity is undergoing rapid and worrying changes, partially driven by anthropogenic activities. Human impacts and climate change (e.g. increasing temperature and ocean acidification), which act at different spatial scale, represent the most serious threats to biodiversity and ecosystem structure and function. In this overview, the effects of anthropogenic pressures on unique and valuable Mediterranean systems, such as Cystoseira sp. pl. forest and Posidonia oceanica meadows, are examined. These complex systems, characterized by a high associated biodiversity, are regularly exposed to natural and anthropogenic pressures. Due to the central role they have for several important ecological…

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…