Search results for "Environmental engineering"
showing 10 items of 2674 documents
Spatio-temporal composition of discard associated with the deep water rose shrimp fisheries (Parapenaeus longirostris, Lucas 1846) in the south-centr…
2017
Discarding in fisheries is the fraction of the total catch brought on board and returned to the sea dead or alive for legal or economic reasons. The reduction of discard is one of the main objectives of the European Common Fishery Policy. This study aimed to improve the current knowledge of the discard associated with the deep-water rose shrimp (DPS) fisheries in the south-central Mediterranean Sea. We analyzed data collected from January 2009 to December 2013. Multivariate data analysis and generalized additive models (GAMs) were used to assess the spatio-temporal composition of the discard (which represented 36% of the total catch) and factors influencing its distribution. Multiple analys…
Comparison of stable isotope composition and inorganic and organic contaminant levels in wild and farmed bluefin tuna, Thunnus thynnus, in the Medite…
2009
Abstract Stable isotope composition (δ13C and δ15N) and persistent pollutants, including heavy metals (Hg, Cd, Pb, As, Cu, Zn) and organochlorine compounds (PCBs, HCB and p,p′-DDE), were measured in muscle and liver tissues of wild and farmed bluefin tunas to investigate the changes occurring during the farming period and to assess the quality, in terms of contaminants, of the final product. At the end of farming, the food supplied was clearly integrated into the tuna tissues as derived from stable isotope signatures, and, contrarily to the literature findings obtained for other species, farmed tunas showed slight variations in persistent elements and chemical compounds in comparison with w…
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…
The trophic transfer of persistent pollutants (HCB, DDTs, PCBs) within polar marine food webs.
2017
Biomagnification (increase in contaminant concentrations at successively higher levels of trophic web), is a process that can transversally impair biodiversity and human health. Most research shows that biomagnification should be higher at poles with northern sites having a major tendency to biomagnify Persistent Organic Pollutants (POPs) through their marine food webs. We investigated the biomagnification degree into two marine trophic webs combining carbon and nitrogen stable isotopes and POP analyses. We showed that the Antarctic trophic web was more depleted than the sub-Arctic one and the differences highlighted for the basal part could explain the difference in length between them. Co…
MULTIPLE CLIMATE-DRIVEN CASCADING ECOSYSTEM EFFECTS AFTER THE LOSS OF A FOUNDATION SPECIES
2021
Abstract Climate change is evolving so fast that the related adverse effects on the environment are becoming noticeable. Thus, there is an urgent need to explore and understand the effects generated by multiple extreme climatic events (MECEs) on marine ecosystem functioning and the services provided. Accordingly, we combined long-term in-situ empirical observations in the Mediterranean Sea with a mesocosm manipulation to investigate the concurrence of increasing temperature and hypoxia events. By focussing on a foundation mussel species, we were able to detect several cascade events triggered by a mass mortality event caused by stressful temperature and oxygen conditions, and resulting in a…
Polymer aging affects the bioavailability of microplastics-associated contaminants in sea urchin embryos
2022
Microplastics (MPs) in the marine environment undergo complex weathering factors that can affect their ability to interact with different coexisting environmental contaminants (termed here co-contaminants). In this study, the influence of artificially aging using UV on the sorption of a complex mixture of co-contaminants onto MPs was investigated in order to provide meaningful hypotheses on their individual and combined toxicities on sea urchin embryos. A mixture of artificially aged MPs (PS particles and PA microfibers) combined with 2,2′ ,4,4′ - tetrabromodiphenyl ether (BDE-47), or Cd or Cu, both alone and in a mix, were used to expose embryos of Paracentrotus lividus. The effects of pol…
Transplantation assessment of degraded Posidonia oceanica habitats: site selection and long-term monitoring
2014
A model developed for Zostera marina was adapted and used to select suitable areas for Posidonia oceanica transplantation in the Gulf of Palermo, where recent rehabilitation programmes have reduced human pressure. This model consists of three steps: (1) habitat selection, by calculation of the Preliminary Transplant Suitability Index (PTSI); (2) field assessments and test-transplanting, to evaluate the site suitability and to estimate the effects of tearing on transplant units (about 50%); (3) identification of suitable restoration sites, by calculation of the Transplant Suitability Index (TSI). A new parameter was added to the literature model: the number of grids detached, which is linked…
Bridging the knowledge gap on the distribution and typology of vermetid bioconstructions along the Maltese coastline : an updated assessment
2022
In the Maltese Islands, insufficient attention has been paid to vermetid reefs, endemic Mediterranean bioconstructions widely distributed along the southern part of the basin. As a result, this is a largely-overlooked coastal ecosystem despite the multitude of ecosystem services it provides. The perennial urban development in the Maltese Islands calls for the adoption of urgent action to protect coastal habitats, in particular bioconstructions that increase biodiversity and contribute to mitigating the effects of climate change. The objective of our study was to extensively document the presence and typology of the vermetid reef ecosystems along the coast of Malta and Gozo, assessing the oc…
Biokinetic Behaviour of Autochthonous Halophilic Biomass at Different Salinity: Comparison Between Activated Sludge and Granular Sludge Systems
2017
The main goal of this study was the evaluation of the impact of increasing salinity on halophilic biomass in forms of flocculent and granular sludge for the treatment of hypersaline fish-canning wastewater, focusing on the metabolic behavior of autotrophic biomass. For this purpose, two sequencing batch reactors, one with aerobic granular sludge (GSBR) and the other with flocculent activated sludge (SBR) were monitored. In both reactors, a halophilic biomass was cultivated from a real saline wastewater collected from a fish-canning industry. The salt concentration was stepwise increased (2 gNaCl L-1) from 30 gNaCl L-1 to 50 gNaCl L-1. Therefore, ammonia and nitrite uptake rates for granular…
Greenhouse Gas Emissions from Membrane Bioreactors
2017
Nowadays, it is widely accepted that wastewater treatment plants (WWTPs) are significant sources of greenhouse gas (GHG) emission, contributing to the anthropogenic sources. Among the GHG emitted from WWTPs, nitrous oxide (N2O) has been identified of having the major interest/concern, since its high global warming potential (GWP), is 298 times higher than that of CO2 and also to its capability to react with stratospheric ozone causing the layer depletion. Up to now, most of the experimental investigations have been carried out on conventional activated sludge (CAS) processes. The knowledge of N2O emission from advanced technologies such membrane bioreactors (MBRs) is still very limited. The…