Search results for " REE"
showing 10 items of 167 documents
Preliminary data on the occurrence of alien macroalgae in the vermetid reef along the coasts of Favignana Island (Southern Tyrrhenian Sea)
2017
Intertidal vermetid reefs are highly diverse systems that provide numerous habitats for animal and vegetal species, leading to an increase of intertidal biodiversity. These habitats, particularly vulnerable to environmental changes and human activities, are now experiencing high mortality in several areas of the Mediterranean Sea. Since alien macroalgae are nowadays considered one of the most serious threats to biodiversity and natural ecosystem functioning, we provide a first baseline assessment of the occurrence of alien species in the vermetid reef along the coasts of the Island of Favignana (Egadi Islands Marine Protected Area). Surveyes carried out in 2015 revealed the only presence of…
Simplification, not “tropicalization”, of temperate marine ecosystems under ocean warming and acidification
2021
Ocean warming is altering the biogeographical distribution of marine organisms. In the tropics, rising sea surface temperatures are restructuring coral reef communities with sensitive species being lost. At the biogeographical divide between temperate and tropical communities, warming is causing macroalgal forest loss and the spread of tropical corals, fishes and other species, termed “tropicalization”. A lack of field research into the combined effects of warming and ocean acidification means there is a gap in our ability to understand and plan for changes in coastal ecosystems. Here, we focus on the tropicalization trajectory of temperate marine ecosystems becoming coral-dominated systems…
Do small marinas drive habitat specific impacts? A case study from Mediterranean Sea
2011
Many human activities add new structures to the marine landscape. Despite the fact that human structures cause some inevitable impacts, surprisingly little information exists on the effects of marina on natural marine assemblages. The aim of this paper is to assess habitat-specific response of benthic sessile organisms of rocky shores in relation to the presence of a small marina. Sampling was carried out at three coastal habitats (midshore, lowshore and subtidal) by means of visual censuses adopting an after-control-impact (ACI) experimental design. It appears that the marina affects the structure and composition of benthic communities of both the midshore and the lowshore. Little effect w…
Implication of the biofilm ageing for the settlement of the vermetid gastropod Dendropoma cristatum (Biondi 1857)
2016
Dendropoma cristatumreefs are key-intertidal habitats of the central Mediterranean. Knowledge onD. cristatumbiology is presently scant, particularly on its early life stage. The development of embryos occurs inside the maternal shell, and the crawling larvae settle on hard substrates shortly after hatching. Epilithic biofilm is known to have implications in the settlement of many marine invertebrates; however whether biofilm plays a role in driving the vermetid settlement is unknown. In this study the microbial assemblage ageing is tested as apotentialtriggerforD. cristatumsettlement. A field experiment was set-up to compare the larval settlement rate on removable limestone cubes (5x5x2 cm)…
Settlement performance of the Mediterranean reef-builders Dendropoma cristatum (Biondi 1859) in response to natural bacterial films
2018
The gastropod Dendropoma cristatum is a biogenic engineer of the central Mediterranean, forming reefs along the lower rocky intertidal fringe with a remarkable ecological role. To understand whether reef-associated biofilm cultivable bacterial and biofilm ageing may trigger the settlement of the juvenile snails, a combination of laboratory techniques and field experiments was used. Reef-associated biofilm cultivable bacteria were isolated, and a settlement-choice experiment was performed in situ on artificial biofilms composed of i) a mixture of six biofilm-forming selected isolates, ii) all the cultivable bacteria, and iii) 13-, 23-, 32-day old biofilms formed under naturalconditions. Overall,sett…
Artificial Reefs in North-West Sicily: Comparisons and Conclusions
2000
The most notable features of the biotic colonization and fishing yield of artificial reefs are a straightforward response to local environmental conditions. When applying this assumption to the artificial reefs of north-west Sicily, the features that distinguish the reefs from each other are largely consistent with the major hydrographic characteristics of the Gulf of Castellammare, the Bay of Carini and the Gulf of Palermo. The differences in environmental conditions in the three biotopes have made it possible to compare the colonization of artificial reefs in unpolluted oligotrophic water (Bay of Carini), eutrophic water (Gulf of Palermo) and water with heavy siltation rates (Alcamo Marin…
Avian brood parasitism in a Mediterranean region. hosts and habitat preferences of Common Cuckoos Cuculus canorus
2009
Capsule Cuckoos in Italy support the ‘host preference’ hypothesis. Aims To identify the species parasitized in a Mediterranean area, in Italy; to quantify the frequency of parasitism on each host species; and to determine whether some species and/or habitat types are parasitized more than expected from a homogeneous distribution. Methods Nest records dating from 1865 were compiled from literature, nest card programmes, and personal communication with ornithologists working in the region. Comparisons of parasitism frequencies were made among and within habitats for all cuckoo hosts. Results The most frequently parasitized hosts were Great Reed Warbler, European Robin, Marsh Warbler, Redstart…
Use of social over personal information enhances nest defense against avian brood parasitism
2011
Interactions with conspecifics influence the behavioral repertoire of an organism, as they apply to foraging techniques, song acquisition, habitat selection, and mate choice. Few workers have studied the role of social interactions in molding defense responses, especially the defense of the nest. We tested the effect of social interaction on nest defense of the reed warbler (Acrocephalus scirpaceus), one of the main hosts of the brood-parasitic common cuckoo (Cuculus canorus) in Europe. This parasite reduces its host’s breeding success; therefore, any response that prevents successful parasitism should be selected. Because of their high nesting density and consistent cuckoo-specific respons…
Biznesa procesu reorganizācija komercbankās
2020
Bakalaura darba tēma ir “Biznesa procesu reorganizācija komercbankās”. Bakalaura darba mērķis ir analizēt, kā biznesa procesu reorganizācija tika ieviesta PSB bankā Krievijā, un novērtēt tās ietekmi uz banku un tās klientiem. Darba saturs ir sadalīts trīs daļās. Pirmajā daļā tiek sniegts teorētiskais atspoguļojums ar piedāvātajām biznesa procesu reorganizācijas definīcijām un teorijām (turpmāk - BPR). Darba otrajā daļā ir ietverta vispārīga informācija par PSB Banku Krievijā, un ieviestās BPR analīze. Darba pēdējā daļa ir empīrisks pētījums, kas sniedz kvantitatīvu analīzi par BRP ietekmi, kas ieviesta PSB bankā, Krievijā.
Biogenic habitat shifts under long-term ocean acidification show nonlinear community responses and unbalanced functions of associated invertebrates
2019
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