Search results for "stable isotopes"

Gas geochemistry of shallow submarine vents in the Aegean sea (Greece)

2017

The Aegean area, which is geodynamically very active, is characterised by intense seismic activity, presence of active volcanic systems and anomalous geothermal gradients. Like other regions of intense geodynamic activity it is also characterized by extensive geogenic degassing. Gas manifestations are not only widespread on land but are also very frequent underwater. Many of these, as for example those of Milos and Santorini, are known since long time and have been previously studied although the targets were generally the hot waters or the sediments affected by the emissions (Smith and Cronan 1978, Dando et al. 1995, Price et al. 2013, Megalovassilis 2014).The present study aims at produci…

Hydrogen isotopes (δ2H) of polyunsaturated fatty acids track bioconversion by zooplankton

2022

1. Organisms at the base of aquatic food webs synthesize essential nutrients, such as omega-3 polyunsaturated fatty acids (n-3 PUFA), which are transferred to consumers at higher trophic levels. Many consumers, requiring n-3 long-chain (LC) PUFA, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have limited ability to biosynthesize them from the essential dietary precursor α-linolenic acid (ALA) and thus rely on dietary provision of LC-PUFA. 2. We investigated LC-PUFA metabolism in freshwater zooplankton using stable hydrogen isotopes (δ2H) of fatty acids as tracers. We conducted feeding experiments with the freshwater keystone grazer Daphnia to quantify changes in the δ2…

Benthic foodweb structure in a large shallow lake studied by stable isotope analysis

2014

The benthic foodweb structure of Lake Võrtsjärv, a large (270 km2), shallow, and turbid Estonian lake, was evaluated based on C and N stable-isotope signatures (δ13C, δ15N). Variation in δ13C between sampling sites was not related to site proximity to the littoral zone or the more vegetated southern part of the lake, but rather appeared to be influenced by in-situ site peculiarities. δ13C was stable temporally and between functional feeding groups, a result implying that the whole benthic food web of the lake relies largely on the same C source admixture, essentially particulate organic matter (POM). Thus, the foodweb composition of Lake Võrtsjärv is remarkably homogeneous given the lake’s …

Environmental drivers of lake profundal macroinvertebrate community variation : implications for bioassessment

2011

Supplementary material 1 from: Milardi M, Green AJ, Mancini M, Trotti P, Kiljunen M, Torniainen J, Castaldelli G (2022) Invasive catfish in northern …

2022

Figures and Tables

The Use of Stable Isotope Ratio Analysis to Trace European Sea Bass (D. labrax) Originating from Different Farming Systems

2020

This study aimed to determine whether isotopic ratio mass spectrometry (IRMS) can discriminate farmed European sea bass according to different farming systems and geographic origins. Dicentrarchus labrax of commercial size from three different rearing systems (concrete tank inland, sea cages, and extensive methods in valleys or salt works) were collected at the trading period (autumn&ndash

Italica (Seville, Spain): use of local marble in Augustan age

2010

This study concerns 51 marble finds made of “Cipollino verde” coming from the ancient city of Italica (north of the modern city of Santiponce, 9 km NW of Seville, Spain), the earliest Roman settlement in Spain, founded in 206 B.C. The aim of this work was to determine their provenance from Greek and Italian quarries or from local quarries worked in the Iberian Peninsula. Thin-section optical microscopy, X-ray powder diffraction, bulk rock chemistry and O, C and Sr stable isotope analyses were carried out. Results were compared with literature data on “Cipollino verde” marbles quarried in southern Euboea (Greece), Apuan Alps (Italy), Almería, Extremoz, Seville (Spain) and Évora (Portugal). T…