Search results for "Environmental Monitoring"
showing 10 items of 609 documents
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…
Horizontal and vertical food web structure drives trace element trophic transfer in Terra Nova Bay, Antarctica
2019
Abstract Despite a vast amount of literature has focused on trace element (TE) contamination in Antarctica during the last decades, the assessment of the main pathways driving TE transfer to the biota is still an overlooked issue. This limits the ability to predict how variations in sea-ice dynamics and productivity due to climate change will affect TE allocation in the food web. Here, food web structure of Tethys Bay (Terra Nova Bay, Ross Sea, Antarctica) was first characterised by analysing carbon and nitrogen stable isotopes (δ13C, δ15N) in organic matter sources (sediment and planktonic, benthic and sympagic primary producers) and consumers (zooplankton, benthic invertebrates, fish and …
Stable isotope evidence for the environmental impact of a land-based fish farm in the western Mediterranean
2004
Isotopic examination (delta(13)C and delta(15)N) of organic matter sources and consumers was used to assess the impact and trace the dispersal of wastewater from a land-based fish farm in western Mediterranean. The results provide evidence of the non-negligible effect of aquaculture facilities on the natural stable isotopic composition of organisms. Aquaculture waste entered the food web, altering the natural isotopic composition of organic matter sources at the base and the upper trophic levels. Nitrogen-rich fish waste mainly affected delta(15)N values, while delta(13)C showed less alteration. Waste seemed to disperse widely enough to affect the isotopic composition at the study site abou…
HCB, p,p'-DDE and PCB ontogenetic transfer and magnification in bluefin tuna (Thunnus thynnus) from the Mediterranean Sea.
2007
The bluefin tuna, Thunnus thynnus (Linnaeus 1758), is biologically and economically important in the Atlantic--Mediterranean ecosystems. Bluefin tuna feed on diverse food items depending on their age, thus they occupy different trophic levels during their lifespan. Hexachlorobenzene (HCB), p,p'-DDE and polychlorinated biphenyls (PCBs) are well-known persistent organic pollutants (POPs) in the Mediterranean basin. The relationship between stable isotopes of nitrogen (N) and the POP residue levels in tissues has recently increased knowledge on the link between the trophic levels and the contaminant accumulation. Trophic levels were estimated by using 15N/14N ratio (delta15N) and HCB, p,p'-DDE…
Trace elements and stable isotopes in penguin chicks and eggs: A baseline for monitoring the Ross Sea MPA and trophic transfer studies.
2021
Multi-tissue trace elements (TEs), C, N concentrations and stable isotopes (δ13C, δ15N) of chick carcasses and eggs of Adelie and Emperor penguins were studied to i) provide reference data before the recent institution of the Ross Sea Marine Protected Area (Antarctica), and ii) provide conversion factors that allow estimating C, N, δ13C and δ15N in edible tissues from non-edible ones, thus improving the use of stable isotopes in contamination and trophic transfer studies. Higher concentrations of As, Cd, Cr, Cu, Hg, Mn and Pb were found in chick carcasses than in eggs, suggesting increasing contamination in recent decades and high toxicity risks for penguin consumers. Isotopic conversion fa…
Effect of different substrata on rhizome growth, leaf biometry and shoot density of Posidonia oceanica
2013
The effects of different substratum typologies on Posidonia oceanica growth and morphology were estimated in four Sicilian meadows using Generalized and Linear Mixed Models combined with retrodating and biometric analyses. Substratum exerted a multiple effect, resulting in different biometric features for P. oceanica shoots settled on rock from those growing on sand and matte. On rock, values for growth rate, leaf length and shoot surface were lower than those on other substrata, with 42%, 23% and 32% the highest degree of difference respectively. The present study may have interesting methodological consequences for the comprehensive understanding of the causative variables potentially aff…
Baseline assessment of heavy metals content and trophic position of the invasive blue swimming crab Portunus segnis (Forskål, 1775) in the Gulf of Ga…
2018
This study provides a baseline assessment of cadmium, copper, iron, manganese, lead, and zinc concentrations in muscles, gills, and exoskeleton of the Lessepsian blue swimming crab Portunus segnis captured in the Gulf of Gabès (Southern Mediterranean Sea, Tunisia) in November 2015. Furthermore, the species’ trophic position is estimated using CN stable isotope analysis. The exoskeleton showed the lowest metal contents; in soft tissues, the essential Cu, Fe, and Zn and the non-essential Cd, Mn, and Pb showed the highest and lowest concentrations, respectively. The crab was characterized by a trophic position of 3.32, confirming its carnivorous trophic habits. Compared with literature data on…
Highly contaminated areas as sources of pollution for adjoining ecosystems: The case of Augusta Bay (Central Mediterranean).
2014
An assessment of trace element and polycyclic aromatic hydrocarbon (PAH) contamination based on surface sediments collected in summer 2012 was carried out in Priolo Bay adjoining one of the most polluted areas of the Mediterranean Sea, the industrial Augusta harbour (Italy, Central Mediterranean). Inorganic and organic contaminants were generally not remarkable. Occasional elevated concentrations of Hg, Cd, Ni and PAHs exceeding sediment quality guidelines were detected in the northern sector of Priolo Bay, close to Augusta harbour, possibly as a result of water drainage of industrialised and urbanised areas and/or potential direct export of contaminated material from Augusta harbour, whose…
Heterotrophic bacteria community and pollution indicators of mussel--farm impact in the Gulf of Gaeta (Tyrrhenian Sea).
2001
Field studies were carried out to determine and compare the impact of organic loads due to the biodeposition of a mussel farm on the water quality and sediment in a coastal area of the Tyrrhenian Sea (Western Mediterranean). A total of five environmental and five microbial parameters were examined from March, 1997 to February, 1998 on a monthly basis at three stations: the first was located under the mussel farm, the second located at about 40 m away from the mussel farm, while the third designed as a control was at about 1-km. No clear changes in the physical characteristics of the water masses were observed, comparing the three sampling sites and the water column generally showed homogene…
SmartWave: A Smart Platform for Marine Environmental Monitoring
2021
In recent years, the interest in the study of seas and oceans has dramatically increased as they are considered of primary importance for forecasting catastrophic events or for supporting blue economy, as well as the marine tourism, improving the tourist reception or enhancing any marine-related activity. This led to the development of IT platforms that allow to monitor the marine environment and provide a number of services to different kinds of final users, whether they are private individuals interested in the status of the seas, or companies whose business depends on the marine environmental monitoring. The main limitations of current platforms are due to such a difference between free …