Search results for "ISOTOPE"

Inferring Phytoplankton, Terrestrial Plant and Bacteria Bulk δ¹³C Values from Compound Specific Analyses of Lipids and Fatty Acids.

2015

Stable isotope mixing models in aquatic ecology require δ13C values for food web end members such as phytoplankton and bacteria, however it is rarely possible to measure these directly. Hence there is a critical need for improved methods for estimating the δ13C ratios of phytoplankton, bacteria and terrestrial detritus from within mixed seston. We determined the δ13C values of lipids, phospholipids and biomarker fatty acids and used these to calculate isotopic differences compared to the whole-cell δ13C values for eight phytoplankton classes, five bacterial taxa, and three types of terrestrial organic matter (two trees and one grass). The lipid content was higher amongst the phytoplankton (…

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

2011

The impact of Mt. Etna volcanic emissions on the atmospheric deposition: developments and improvements during three decades of studies

2022

Volcanic emissions are an important source of gases and particles to the atmosphere. Mount Etna discharges a permanent volcanic plume consisting of water vapor and gaseous species (CO2, SO2, HCl and HF, mainly), metals, acid droplets, and solid particles. This plume interacts with meteoric water during precipitations events, so the chemical signature of the plume is impressed on the rainwater. Over the past 32 years, the impact of Etna's emissions on atmospheric deposition has been investigated in many research projects by our team. Sampling methodologies and analytical procedures have been improved over the years. The first study of the concentration of water-soluble inorganic ions in week…

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

Terrestrial carbohydrates support freshwater zooplankton during phytoplankton deficiency

2016

Article

Stable carbon and oxygen isotope fractionation in bivalve (Placopecten magellanicus) larval aragonite

2008

Abstract The relationship between stable isotope composition (δ13C and δ18O) in seawater and in larval shell aragonite of the sea scallop, Placopecten magellanicus, was investigated in a controlled experiment to determine whether isotopes in larval shell aragonite can be used as a reliable proxy for environmental conditions. The linear relationship between δ13CDIC and δ13Caragonite (r2 = 0.97, p  δ 13 C DIC = 1.15 ( ± 0.05 ) ∗ δ 13 C aragonite - 0.85 ( ± 0.04 ) The relationship between δ13CDIC and δ13Caragonite described for P. magellanicus resulted in larval shell aragonite that was depleted on average by 1.82‰ (SD = 0.22‰, range = 1.1–2.1‰) from predicted equilibrium values based on the r…

Late Jurassic (Kimmeridgian–Tithonian) stable isotopes (δ18O, δ13C) and Mg/Ca ratios: New palaeoclimate data from Helmsdale, northeast Scotland

2010

Abstract The data presented here provide the first detailed stable isotope ( δ 18 O, δ 13 C) and geochemical (Mg/Ca) investigation of Kimmeridgian–Tithonian belemnites from the Helmsdale Coast, Scotland, UK. Oxygen and carbon stable isotope values from well preserved specimens range from − 2.8 to + 0.3‰ and from − 2.3 to + 2.8‰ respectively. The oxygen isotope data are consistent with palaeotemperatures of up to 24 °C in the Early Kimmeridgian cymodoce Zone and down to 11 °C in the Mid Tithonian rotunda–fittoni Zones. These estimates are strongly supported by the Mg/Ca data, which also indicate a cooling episode (and very similar palaeotemperatures, 11–22 °C) at this time. The cooling event…

Carbon cycle and sea-water palaeotemperature evolution at the Middle-Late Jurassic transition, eastern Paris Basin (France).

2014

14 pages; International audience; A very high-resolution carbon and oxygen stable isotope analysis (bulk-carbonate) of a biostratigraphically well-constrained Callovian-Oxfordian series is provided here for the first time. The homogeneity of the clayey series and the weak diagenetic alteration allow the isotopic signal variations to be considered as primary in origin. A prominent and brief negative excursion in the δ13C curve (−2‰), occurring at the start of the Middle Callovian (Jason Zone - Obductum Subzone) and correlated regionally, suggests a possible methane release. The increasing δ13C values thereafter up to the Early Oxfordian, concomitant with a warming episode, highlight the buri…

Variation in Sr uptake in the shell of the freshwater gastropod Bithynia tentaculata from Lake Arreo (northern Spain) and culture experiments

2010

The Sr uptake features in Bithynia tentaculata aragonite shells from monthly collections in Lake Arreo (northern Spain) over a two-year period are compared with those from the same species grown in culture experiments with similar waters under controlled temperature. The shell aragonite of B. tentaculata from Lake Arreo formed in isotopic equilibrium with the lake water. A comparison of the stable oxygen isotope values (δ18O) from the shells and waters allowed the selection of suitable shells for Sr uptake studies. The Sr/Ca molar ratio in B. tentaculata shells (Sr/Cashell) from the lake and from the culture experiments positively correlate with some chemical parameters like conductivity an…

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