Search results for " benthos"

Guano-Derived Nutrient Subsidies Drive Food Web Structure in Coastal Ponds.

2016

A stable isotope study was carried out seasonally in three coastal ponds (Marinello system, Italy) affected by different gull guano input to investigate the effect of nutrient subsidies on food web structure and dynamics. A marked 15N enrichment occurred in the pond receiving the highest guano input, indicating that gull-derived fertilization (guanotrophication) had a strong localised effect and flowed across trophic levels. The main food web response to guanotrophication was an overall erosion of the benthic pathway in favour of the planktonic. Subsidized primary consumers, mostly deposit feeders, switched their diet according to organic matter source availability. Secondary consumers and,…

Energetics, Particle Capture and Growth Dynamics of Benthic Suspension Feeders

2017

Marine benthic communities are dominated by suspension feeders, including those actively pumping water, passively encountering particles, or some combination of the two. The mechanisms by which particles are encountered and retained are now well known for a range of water flow conditions and organism morphologies. Recent research has attempted to quantify the energetic components of suspension feeding, including intake of particles, pumping rates, and metabolic costs of these activities. Energetic models depend strongly on environmental conditions, including temperature, flow speed, and food availability, for example. The effects of these variables have been combined for realistic scenarios…

Towards a local mass mortality of the Mediterranean orange coral Astroides calycularis (Pallas, 1766) in the Pelagie Islands Marine Protected Area (I…

2022

In late summer 2020, a widespread mortality event severely affected colonies of the Mediterranean endemic orange coral Astroides calycularis in the Pelagie Islands (Strait of Sicily, southern Mediterranean Sea). The degree of the mortality impact at seven study sites of the archipelago (five within the Pelagie Islands Marine Protected Area) was quantified by estimating the proportion of affected colonies in populations of A. calycularis. Five of the seven surveyed sites revealed a low degree of impact, but Punta Ruperta and Cala Creta (both on the island of Lampedusa) showed a medium impact with values of 32.3% and 30.5% of affected colonies respectively. The 2020 mortality event coincided …

Marine strategy framework for detecting mass mortality: From local surveys to monitoring improvements in the coralligenous habitat

2023

Mediterranean coralligenous assemblages are threatened by the effects of climate change and human activities that have led to mass mortality events (MMEs) in recent decades. The ecological roles of this habitat and the possible consequences of its loss have necessitated the scientific analysis of MMEs on a Mediterranean regional scale, highlighting the need of new standardized monitoring and data collection tools across the basin. In September 2021, during the monitoring activities of the Marine Strategy Framework Directive (MSFD) for the coralligenous habitat of the Egadi Islands Marine Protected Area (MPA), an MME of the red gorgonian Paramuricea clavata was recorded. Five of the six surv…

Bottom-Up Control of Macrobenthic Communities in a Guanotrophic Coastal System

2015

Soft bottom macrobenthic communities were studied seasonally in three coastal ponds (Marinello ponds, Italy) at increasing distances from a gull (Larus michahellis) colony to in- vestigate the effect of seabird-induced eutrophication (i.e. guanotrophication) on macro- benthic fauna.We hypothesized that enhanced nutrient concentration and organic load caused by guano input significantly alter the trophic and sedimentological condition of ponds, affecting benthic fauna through a bottom-up control. The influence of a set of envi- ronmental features on macrobenthic assemblages was also tested. Overall, the lowest macrobenthic abundances and functional group diversity were found in deeper sites,…

Latitudinal variations in positive and negative effects of invertebrates on rocky shore biofilm

2011

Effects of ocean acidification on rocky shore communities at Vulcano Island

2010

Signals of loss: Local collapse of neglected vermetid reefs in the western Mediterranean Sea

2022

During the summer of 2022, an extensive die-off of Dendropoma cristatum and other marine organisms associated with vermetid reefs was observed in the western Mediterranean Sea (northern coast of Sicily). Quantitative data from more than 300 km of coastal stripe indicated that the percentage of dead D. cristatum specimens, showing empty and/or transversely fractured shells, ranged from 64 to 84 % in populations having a density of 2900-4730 ind./m2, suggesting that millions of organisms had recently died along the Sicilian coast. This high mortality range coincided with prolonged desiccation events during which biogenic vermetid reefs were exposed to extreme warm-air conditions for several c…

PROSPETTIVE E CRITICITÀ SUL RUOLO DEL BENTHOS MEDITERRANEO NELLA DIRETTIVA SULLA MARINE STRATEGY

2013

In Europe, the Marine Strategy Framework Directive (MSFD) and the Water Framework Directive (WFD) are the main regulations for the protection of water bodies. The translation of their principles into valid and practical approaches is the main challenge for the scientific community. An additional and even more severe problem is related to the MSFD application in the Mediterranean area. The aim of the present contribution is to picture the present situation in Italy, as far as the benthic communities in the MSFD are concerned, pinpoint some conceptual and practical critical points, and possibly suggest some new tools useful for the definition of Good Ecological Status (GES).

Ruolo dell’interazione tra impatto antropico e inclinazione del substrato nella struttura delle comunità bentoniche di fouling

2006

I substrati duri artificiali sono idonei per verificare la risposta ecologica degli organismi del benthos a differenti livelli di variabilità dell’interazione tra fattori antropici, abiotici e biotici. La combinazione tra impatto umano e inclinazione del substrato può influenzare la struttura di comunità. Lo studio è stato condotto nella primavera 2006 nel Golfo di Palermo, nel quale sono state individuate due località a diverso grado di impatto antropico derivante da attività industriali e da reflui urbani. In ogni località, sono stati scelti siti a differente complessità geometrica (inclinazione orizzontale vs verticale). I campionamenti sono stati effettuati sulla fascia mesolitorale di …