Search results for " Mediterranean sea."

Predicting biological invasions in marine habitats through eco-physiological mechanistic models: a case study with the bivalveBrachidontes pharaonis

2013

Aim We used a coupled biophysical ecology (BE)-physiological mechanistic modelling approach based on the Dynamic Energy Budget theory (DEB, Dynamic energy budget theory for metabolic organisation, 2010, Cambridge University Press, Cambridge; DEB) to generate spatially explicit predictions of physiological performance (maximal size and reproductive output) for the invasive mussel, Brachidontes pharaonis. Location We examined 26 sites throughout the central Mediterranean Sea. Methods We ran models under subtidal and intertidal conditions; hourly weather and water temperature data were obtained from the Italian Buoy Network, and monthly CHL-a data were obtained from satellite imagery. Results …

A Mediterranean record of Eulalia ornata (Annelida: Phyllodocidae) corroborating its fidelity link with the Sabellaria alveolata-reef habitat

2015

Among marine habitats Sabellaria alveolata -reefs deserve protection since they provide important ecosystem services and positive effects on biodiversity. Several marine species are listed among the S. alveolata -reef associated fauna, but characteristic species were seldom reported. Eulalia ornata (Annelida, Phyllodocidae) might represent an exception, since it appears common/abundant in S. alveolata -reefs of the Eastern Atlantic. The most evident geographical mismatch in the distributions of E. ornata and these biogenic reefs occurs in the Mediterranean Sea, where S. alveolata -reefs are commonly found, but E. ornata was never recorded, whilst E. viridis , a non-Mediterranean species, wa…

Nematode community response to fish-farm impact in the western Mediterranean.

2002

A previous investigation on fish-farm biodeposition effects on benthos, carried out in the Gaeta Gulf (northwestern Mediterranean Sea), revealed a strong impact on meiofaunal assemblages. This study implements these findings by examining in detail the nematode assemblage and its response to organic enrichment from the start of a fish farm activity to the conclusion of the fish rearing cycle. Density, community structure and individual size were utilised for univariate (genus, trophic diversity and abundance patterns) and multivariate analyses (MDS) in order to identify the best descriptors of impact and the response of the nematode assemblages. Nematodes displayed significantly reduced dens…

The impact of climate change on Mediterranean intertidal communities: losses in coastal ecosystem integrity and services

2014

As has been shown for other ecosystems, the ecological and socio-economic impacts of climate change on Mediterranean intertidal habitats are highly variable in space and time. We conducted field and laboratory measurements of cellular, ecophysiological and behavioural responses of selected intertidal invertebrates (mussels, gastropods and sponges) and completed a literature review to determine what is known of socioeconomic consequences of these biological changes. Results suggest significant gaps in our knowledge that may impede a complete understanding of likely impacts (physical, biological, and socioeconomic) and that sufficient data for such an analysis is available only for mussels. A…

Parameterisation of bivalve functional traits for mechanistic eco-physiological dynamic energy budget (DEB) models

2013

Mechanistic models such as those based on dynamic energy budget (DEB) theory are emergent ecomechanics tools to investigate the extent of fitness in organisms through changes in life history traits as explained by bioenergetic principles. The rapid growth in interest around this approach originates from the mechanistic characteristics of DEB, which are based on a number of rules dictating the use of mass and energy flow through organisms. One apparent bottleneck in DEB applications comes from the estimations of DEB parameters which are based on mathematical and statistical methods (covariation method). The parameterisation process begins with the knowledge of some functional traits of a tar…

Initial Fish-Farm Impact on Meiofaunal Assemblages in Coastal Sediments of the Western Mediterranean

1999

We studied the initial impact of organic loads due to the biodeposition of a new fish farm in a non-impacted coastal area of the Tyrrhenian Sea (Western Mediterranean). Sediment chemistry and meiofaunal assemblages were investigated from July 1997 to February 1998 on a monthly basis at two stations: the first was located under the fish farm, while the second was at about 1 km distance, and served as control. Variations in the biochemical composition of the sedimentary organic matter and meiofaunal community structure were also related to changes in reared fish biomass. The presence of the cage-induced rapid changes in the benthic compartment: the sediments reached rapidly (i.e., after only …

Assessing vermetid reefs as indicators of past sea levels in the Mediterranean

2020

Abstract The endemic Mediterranean reef building vermetid gastropods Dendropoma petraeum complex (Dendropoma spp) and Vermetus triquetrus develop bio-constructions (rims) on rocky shorelines at about Mean Sea Level (MSL) and are therefore commonly used as relative sea-level (RSL) markers. In this study, we use elevations and age data of vermetid reefs to (1) re-assess the vertical uncertainties of these biological RSL indicators, and (2) evaluate the vertical growth rates along a Mediterranean east-west transect, in attempt to explain the differences found in both growth rates and uncertainties. In Israel, Differential Global Positioning System (DGPS) and laser measurements relative to the …

Growth and reproductive simulation of candidate shellfish species at fish cages in the Southern Mediterranean: Dynamic Energy Budget (DEB) modelling …

2012

Abstract A Dynamic Energy Budget (DEB) model is used to simulate growth and reproduction of the shellfish Mytilus galloprovincialis and Crassostrea gigas in an integrated multi-trophic aquaculture (IMTA) farm scenario situated in the Southern Mediterranean (the Gulf of Castellammare, Sicily). We modelled the effect of primary production enrichment at fish cages on shellfish growth and life history traits using 4 years-hourly temperature data (01 January 2006–31 December 2009) at a depth of 1 m. Outputs of the DEB simulations were: the maximum theoretical total shell length of shellfish, the potential reproductive outputs and the mean annual von Bertalanffy growth rate. There was a mean incr…

Cultivation of the Mediterranean amberjack, Seriola dumerili (Risso, 1810), in submerged cages in the Western Mediterranean Sea

2000

The growth rate, survival and food conversion ratio (FCR) of the Mediterranean amberjack (Seriola dumerili, Risso, 1810) was ascertained in cultivation using submerged net cages in the Gulf of Castellammare (NW Sicily), from September to December 1994. Two net cages (volume = 75 m3) were placed at a depth of 10 m in a sheltered area 1000 m off the coast. Juveniles (mean total length = 141.4 ± 34 2 mm; mean total wet weight = 48 ± 28.1 g) were caught in the gulf under floating wreckage with a purse seine and transplanted to the cages (n = 800 per cage) in August. Fish in one cage, group A, were fed with fish scraps whilst fish in group B were fed with pellets The total length and body wet we…

How do non-indigenous species affect native species and habitats?

Biological invasions are a key driver of global change, affecting biodiversity and natural ecosystem functioning. Non-indigenous species (NIS) with significant established and expanding populations have the potential to become invasive, with serious environmental, socio-economic, and/or human health consequences. Mediterranean Islands (including Marine Protected Areas “MPAs”), important hotspots of biodiversity, are particularly vulnerable to NIS invasions. Understanding the effects of NIS species on biodiversity, as well as their current distribution and expansion trends, is therefore critical for creating effective conservation strategies. Here, we present three different case studies fro…