1,721,045 research outputs found
The "melting pot" biota of the lagoon of Venice, a hotspot of marine NIS introductions in the Mediterranean Sea.
No full textThe enlargement of the Suez Canal – Erythraean introductions and management challenges
No full textThe Suez Canal is the main pathway of introduction of non-indigenous species into the Mediterranean Sea. The successive enlargements of the Suez Canal have raised concern over increasing propagule pressure resulting in continuous introductions of new non-indigenous species and associated degradation and loss of native populations, habitats and ecosystem services. The United Nations Environment Programme (UNEP) through its Barcelona Convention has pledged to protect the biological resources, habitats and ecosystem services of the Mediterranean Sea, and have committed to spatial protection measures. Yet, UNEP shied away from discussing, let alone managing, the influx of tropical non-indigenous biota introduced through the Suez Canal. Surveys, funded by the Regional Activity Centre for Specially Protected Areas (UNEP RAC/SPA), established by the Contracting Parties to the Barcelona Convention, revealed that marine protected areas in the eastern Mediterranean have been inundated by these non-indigenous species, and may in fact function as hubs for their secondary dispersal. We call attention to the failure of an environmental policy that left the entire Mediterranean Sea prone to colonization by highly impacting non-indigenous species, including poisonous and venomous ones. Scientific research has been documenting this bioinvasion for over a century, yet beyond the ambit of marine scientists there is a lack of awareness of the scale of Mediterranean-wide consequences and scant appetite to enact the necessary environmental policies
Spreading and production of invasive alien macrophytes in the Venice Lagoon.
No full textThe Venice lagoon is the Italian hotspot of non-indigenous species (NIS) in the Mediterranean Sea. A critical revision of the alien macroalgae estimates the actual number of introductions in 28 taxa, 54% of the total introduced macroalgae present along the Italian coasts; many cryptogenic species reported in the previous lists have been excluded, whereas a few taxa such as Ulva fasciata/Ulva lactuca require confirmation. Out of these 29 NIS, 5 are Chlorophyceae, 6 Phaeophyceae, 17 Rhodophyceae; 4 taxa are invasive (Gracilaria vermiculophylla, Sargassum muticum, Undaria pinnati
fida, Codium fragile subsp. fragile ) and 3 potentially invasive (Hypnea flexicaulis, Grateloupia turuturu, Heterosiphonia japonica ). Other NIS (Agardhiella subulata,
Solieria filiformis) are invasive only in the Venice Lagoon or nearby (lagoons of the Po Delta and the pond Pialassa della Baiona in Emilia-Romagna Region).
G. vermiculophylla, A. subulata, S. filiformis and H. flexicaulis are able to grow also by free floating or in soft substrata and present a high invasion risk. The other taxa are benthic species whose presence depends on the availability of hard substrata.
S. muticum and U. pinnatifida have raised public concern after having colonized
the banks of the historical centre of Venice and Chioggia; however, their biomass is negligible: ca. 0.2 ktonnes for Undaria and 6-7 ktonnes for Sargassum, accounting for ca. 5-7% of the total lagoon macroal gal biomass. The most invasive species is surely G. vermiculophylla , first recorded in 2008 in some confined areas (Lago dei Teneri) of the central lagoon and now (2014) occurring between Venice, the industrial
area and Campalto. In the latter area it has completely replaced the laminar Ulvaceae that in July 2013 had triggered an anoxic crisis. Despite the invasive behavior of G. vermiculophylla , it is not considered to adversely affect the environment; furthermore this species is studied for agar, sugar or alcohol production
Updating of alien macroalgae in the Venice Lagoon, new introductions and cryptogenic species.
No full textA revision of the number of NIS in the Italian coasts shows an alarming increase of\ud
alien macroalgae: from 35 taxa in 2012 to 52 taxa in 2014, out of which many are invasive, potentially invasive or punctual records, while others are cryptic species requiring further investigation. The Venice Lagoon is the Italian site with more reports accounting for 54% of the total NIS recorded in the Italian coasts and looks like a hotspot from which NIS can be exported in other environments. The decade characterized by higher number of new NIS records was 1991-2000 and the vector responsible of the\ud
major number of introductions was aquaculture (mollusc importation for shellfish culture and live seafood trade) followed by vessels
Distribution and morphological variation of colonies of the bryozoan Pentapora fascialis (Bryozoa: Cheilostomata) along the western coast of Italy
Full text linkL’influenza della profondità sulla densità della microalga bentonica Chrysophaeum taylorii
No full textAlien species spreading via biofouling on recreational vessels in the Mediterranean Sea
No full textDespite the Mediterranean being both a hotspot for recreational boating and for non-indigenous species (NIS), no data currently exists on the recreational boating sector's contribution to the spread of NIS in this Sea. To improve the basis for management decisions, a wide-scale sampling study on the biofouling communities of recreational vessels and marinas was undertaken. Specifically, we surveyed over 600 boat owners and sampled the same boat hulls for NIS in 25 marinas across the Mediterranean, from France to Cyprus, to determine which factors (i.e. boat characteristics, travel behaviour, home marina) are associated with higher NIS richness on boat hulls. Among the surveyed boats, we found recreational vessels to travel considerably, averaging 67 travel days and 7.5 visited marinas per annum. This results in a high potential for spreading NIS, especially as 71% of sampled vessels host at least one (and up to 11) NIS. Boats with high NIS richness strongly correlate with home marinas with high NIS richness. Over half of the vessels were carriers of NIS which were not yet present in the marinas they were visiting. The presence of biofouling in niche areas of the hull (i.e. in the cavities and metallic parts) emerges as the best predictor for NIS richness on boats, along with longer times since their last cleaning and antifouling applications. Interestingly, colonization of NIS occurred rapidly, even on boats that had recently had their hulls cleaned professionally. Synthesis and applications. We demonstrate that recreational boating has a very high capacity for the spread of non-indigenous species (NIS) in the Mediterranean, due to both high NIS richness on boats and extensive travel. To counteract the spread of NIS, routine monitoring for new NIS needs to be established for both marinas and vessels, along with frequent pontoon cleaning. Additionally, policy should require preliminary screenings for incoming vessels from new countries, especially those emanating from high-risk marinas. The niche areas of the boat hulls should be checked first for biofouling, which was the best predictor for NIS richness since they often go overlooked with in-water cleanings are rarely have antifouling applied to them
Primi risultati della sperimentazione di un nuovo strumento per stimare la densitá della microalga bentonica Chrysophaeum taylorii lewis & bryan
No full textLong-term ecological evolution of a high-altitude lake in the Central-Eastern Italian Alps as showed by palaeolimnological proxies
No full textHigh-altitude lakes are particularly susceptible to climate change and anthropic impacts that modify the ecosystem environmental features and trigger the response of the biota. Palaeolimnological studies based on the analysis of proxies preserved in lake sediments aim at reconstructing the ecological evolution of lakes and surrounding environment at secular to millennial scale. This allows to evaluate the lake response to various external influences and to formulate hypotheses about future ecological evolution. We analysed two parallel cores sampled from a high-altitude lake located in the Ortles-Cevedale Group in the Central-Eastern Italian Alps (Lago Marmotte). A small glacier occupied the upper part of the lake catchment until the 1970s, while currently only discontinuous permafrost is still present. The aim of the present study was to verify whether the recent deglaciation of this Alpine catchment led to lake ecological changes that are preserved by sediment proxies, in particular stable C and N isotopes of sediment organic matter, and subfossil algal pigments and diatoms. The results show that the lake underwent two major environmental and ecological changes, i.e. after the end of the Little Ice Age (~150 years ago) and during the last 40 years, after the acceleration of the global warming
Esperimento di rimozione degli ammassi mucillaginosi della microalga alloctona Chrysophaeum taylorii Lewis e Bryan
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