Contribution of catabolic tissue replacement to the turnover of stable isotopes in Danio rerio

2006 ◽  
Vol 84 (10) ◽  
pp. 1453-1460 ◽  
Author(s):  
Rania A. Tarboush ◽  
Stephen E. MacAvoy ◽  
Stephen A. Macko ◽  
Victoria Connaughton
Keyword(s):  
Stable Isotopes ◽  
Isotopic Composition ◽  
Danio Rerio ◽  
Trophic Interactions ◽  
Isotopic Signature ◽  
Isotopic Equilibrium ◽  
Nutrient Sources ◽  
Dietary Shift ◽  
Tissue Replacement ◽  
Water Fish

Stable isotopes of carbon, nitrogen, and sulfur in organisms can trace nutrient sources and determine trophic interactions. However, time is required for an organism to reflect the isotopic composition of its diet. The rate at which an organism incorporates the isotopic signature of its food has a growth (k) component and a metabolic tissue replacement (m) component. This study shows that metabolic tissue replacement accounts for between 68% and 80% of the observed changes in isotopic signature in zebra danio ( Danio rerio (Hamilton, 1822)) muscle following a dietary shift, with the remainder owing to growth of new tissue. The half-lives of carbon, nitrogen, and sulfur were ~53, ~147 and ~58 days, respectively. This indicates that a significant period of isotopic disequilibria exists before zebra danio resemble dietary isotopic composition. These results show that catabolic replacement of tissue, as well as growth, must be taken into account when predicting the rate of isotope incorporation in warm-water fish. When using isotopic ratios to decipher food webs and trophic interactions, researchers should be aware that the often held assumption of isotopic equilibrium between diet and consumer may be violated.

Monitoring isotopic signature in headwaters to trace environmental changes: an example in the Italian Alps

2020 ◽  
Author(s):  
Chiara Marchina ◽  
Valeria Lencioni ◽  
Francesca Paoli ◽  
Marzia Rizzo ◽  
Gianluca Bianchini
Keyword(s):  
Stable Isotopes ◽  
Isotopic Composition ◽  
Natural Waters ◽  
Environmental Changes ◽  
Isotopic Signature ◽  
Early Summer ◽  
Freshwater Ecosystems ◽  
Climate Variables ◽  
Italian Alps ◽  
Historical Series

<p>Glaciers are shrinking due to global warming, resulting in a diminishing contribution of ice- and snowmelt to headwaters with consequences on freshwater ecosystems. The stable isotopic compositions in natural waters (δ<sup>18</sup>O and δ<sup>2</sup>H) respond to environmental variation very sensitively and can indicate the change of geographic environment or mark the recharge of runoff (Boral 2019, Zuecco 2019). Thus, stable isotopes have been used as natural tracers to constrain the contributions of different water sources to streamflow, including snowmelt, icemelt and groundwater baseflow (Boral 2019). Within this context, we tested if water stable isotopes are spatio-temporal tracers of: i) water in periglacial habitats, being the isotopic signature of surface water inherited from the snow/icemelt, groundwater, and rainfall; ii) regional (year-specific) meteorological conditions, being the isotopic signature of precipitations affected by air temperature, humidity and aqueous vapour origin, ascribing stable isotopes in the list of the “essential climate variables″ (ECV). In this light, we investigated the ionic and isotopic composition (δ<sup>18</sup>O and δ<sup>2</sup>H) of six high altitude streams and one pond in the Italian Alps (Noce and Sarca basins) during the ablation season in 2018. Differences between habitat types (pond, kryal, rhithral, krenal) were detected. More negative values of δ<sup>18</sup>O and δ<sup>2</sup>H were recorded in the kryal and glacio-rhithral sites dominated by ice and snowmelt, in early summer. Less negative values were recorded in these sites in late summer and in krenal sites, dominated by groundwater and rainfall inputs. The isotopic results also showed that the complex alpine orography influences the air masses and moist, ultimately resulting in isotopic differences in precipitations of neighbouring, but distinct catchments (Sarca and Noce basins). As average, less negative values were recorded in the Sarca basin, characterized by a higher contribution of precipitation of Mediterranean origin. Finally, isotopic composition of the entire water population appeared to be strongly influenced by the regional climatic anomaly of the year 2018, which was anomalously warm in respect to the historical series 1961- 1990. This study will provide additional clues for the climate-change debate, proposing water isotopes as “essential climate variables″ indicators for assessing change in a warmer future.</p><p> </p><p><strong>Keywords: </strong>stable isotopes, glaciers, essential climatic variables</p><p><strong> </strong></p><p><strong>References: </strong></p><p>Boral S., J. Hydrol., https://doi.org/10.1016/j.jhydrol.2019.123983</p><p>Zuecco G., Hydrol. Process, https://doi.org/10.1002/hyp.13366.</p>

scholarly journals Controls on the isotopic composition of microbial methane

2021 ◽  
Author(s):  
Jonathan Gropp ◽  
Qusheng Jin ◽  
Itay Halevy
Keyword(s):  
Isotopic Composition ◽  
Isotopic Signature ◽  
Environmental Data ◽  
Isotopic Equilibrium ◽  
Sources And Sinks ◽  
Stable Isotopic ◽  
Isotopic Model ◽  
Almost All ◽  
Natural Settings

AbstractMicrobial methane production (methanogenesis) is responsible for more than half of the annual emission of this major greenhouse gas to the atmosphere. Though the stable isotopic composition of methane is often used to characterize its sources and sinks, empirical descriptions of the isotopic signature of methanogenesis currently limit such attempts. We developed a biochemical-isotopic model of methanogenesis by CO2 reduction, which predicts carbon and hydrogen isotopic fractionations, and clumped isotopologue distributions, as functions of the cell’s environment. We mechanistically explain multiple-isotopic patterns in laboratory and natural settings and show that such patterns constrain the in-situ energetics of methanogenesis. Combining our model with environmental data, we infer that in almost all marine environments and gas deposits, energy-limited methanogenesis operates close to chemical and isotopic equilibrium.

scholarly journals Presence of continental and Bay of Bengal moisture in rainfall at Kolkata, revealed through simultaneous observation from land and sea during South-West monsoon of 2004

2016 ◽  
Author(s):  
Shaakir Shabir Dar ◽  
Prosenjit Ghosh
Keyword(s):  
Isotopic Composition ◽  
Bay Of Bengal ◽  
Indian Subcontinent ◽  
Isotopic Signature ◽  
Peninsular India ◽  
Gangetic Plain ◽  
Prevailing Wind Direction ◽  
South West Monsoon ◽  
Continental Source ◽  
Sw Monsoon

Abstract. The backward air mass trajectory analysis (HYSPLIT) during the summer monsoon suggests that the rain which precipitates at Kolkata is generated from a moisture parcel which originates from the Arabian Sea and moves inland over the dry Indian subcontinent or over the Bay of Bengal. We used monthly satellite and ground based measurements of the hydro-meteorological variables together with isotope data from Bangalore, Bay of Bengal and Kolkata and other locations to quantify the contribution of different moisture sources during the SW Monsoon. The vapor mass as it moves under the prevailing wind direction was subjected to isotopic modification due to addition of evaporated moisture from Bay of Bengal and rainout process. This was simulated using Craig and Gordon model and Rayleigh fractionation model respectively. The moisture generated during the process of evaporation from Bay of Bengal surface ocean gets advected towards the continent and precipitates as rainfall or snowfall over the Indo-Gangetic plain. We assumed based on our observation that the initial isotopic composition of vapor originating from the peninsular continental source is similar to our observation recorded at Bangalore station. It is found that the isotopic signature of Bangalore is completely lost albeit the significant contribution of the moisture from Bay of Bengal. To explain the isotopic composition of precipitation at Kolkata during the SW-Monsoon, it was necessary to invoke 75–80 % moisture contribution from the Bay of Bengal whereas the evaporated moisture parcel from the Peninsular India contribute 25 %–35 %.

Ecological and isotopic discrimination of syntopic rodents in a neotropical rain forest of French Guiana

2003 ◽  
Vol 19 (2) ◽  
pp. 209-214 ◽  
Author(s):  
Jean-François Mauffrey ◽  
François Catzeflis
Keyword(s):  
Stable Isotopes ◽  
Isotopic Composition ◽  
Rain Forest ◽  
French Guiana ◽  
Ecological Studies ◽  
Carbon Isotope Ratios ◽  
Photosynthetic Pathways ◽  
Feeding Process ◽  
Neotropical Rain Forest

Stable isotopes are commonly used in ecological studies to infer food resources (Ambrose & DeNiro 1986, Bocherens et al. 1990,1991,1994;Yoshinaga et al. 1991) since isotopic composition is conserved during the feeding process. Moreover,for herbivorous (sensu lato) species, it is often possible to identify the main resource because different photosynthetic pathways generate different values of carbon isotope ratios (Park & Epstein 1961, Sternberg et al. 1984). This allows the characterization of broad biota such as savannas or forest and discrimination of grazers from sympatric folivorous species (DeNiro & Epstein 1978).

scholarly journals An Optimized Snowmelt Lysimeter System for Monitoring Melt Rates and Collecting Samples for Stable Water Isotope Analysis

2019 ◽  
Vol 67 (1) ◽  
pp. 20-31 ◽  
Author(s):  
Andrea Rücker ◽  
Massimiliano Zappa ◽  
Stefan Boss ◽  
Jana von Freyberg
Keyword(s):  
Isotopic Composition ◽  
Isotope Analysis ◽  
Ground Level ◽  
Isotopic Signature ◽  
Small Scale ◽  
Spatial And Temporal Variability ◽  
Environmental Tracers ◽  
Hydrograph Separation ◽  
Stable Water Isotopes ◽  
Restricted Volume

Abstract The contribution of snow meltwater to catchment streamflow can be quantified through hydrograph separation analyses for which stable water isotopes (18O, 2H) are used as environmental tracers. For this, the spatial and temporal variability of the isotopic composition of meltwater needs to be captured by the sampling method. This study compares an optimized snowmelt lysimeter system and an unheated precipitation collector with focus on their ability to capture snowmelt rates and the isotopic composition of snowmelt. The snowmelt lysimeter system consists of three individual unenclosed lysimeters at ground level with a surface of 0.14 m2 each. The unheated precipitation collector consists of a 30 cm-long, extended funnel with its orifice at 2.3 m above ground. Daily snowmelt samples were collected with both systems during two snowfall-snowmelt periods in 2016. The snowmelt lysimeter system provided more accurate measurements of natural melt rates and allowed for capturing the small-scale variability of snowmelt process at the plot scale, such as lateral meltwater flow from the surrounding snowpack. Because of the restricted volume of the extended funnel, daily melt rates from the unheated precipitation collector were up to 43% smaller compared to the snowmelt lysimeter system. Overall, both snowmelt collection methods captured the general temporal evolution of the isotopic signature in snowmelt.

scholarly journals ‘Taking Fishers’ Knowledge to the Lab’: An Interdisciplinary Approach to Understand Fish Trophic Relationships in the Brazilian Amazon

2021 ◽  
Vol 9 ◽  
Author(s):  
Paula Evelyn Rubira Pereyra ◽  
Gustavo Hallwass ◽  
Mark Poesch ◽  
Renato Azevedo Matias Silvano
Keyword(s):  
Stable Isotopes ◽  
Food Webs ◽  
Fish Species ◽  
Trophic Interactions ◽  
Brazilian Amazon ◽  
Trophic Levels ◽  
Trophic Relationships ◽  
Ecological Knowledge ◽  
Data Limitations ◽  
Combining Data

Trophic levels can be applied to describe the ecological role of organisms in food webs and assess changes in ecosystems. Stable isotopes analysis can assist in the understanding of trophic interactions and use of food resources by aquatic organisms. The local ecological knowledge (LEK) of fishers can be an alternative to advance understanding about fish trophic interactions and to construct aquatic food webs, especially in regions lacking research capacity. The objectives of this study are: to calculate the trophic levels of six fish species important to fishing by combining data from stable isotopes analysis and fishers’ LEK in two clear water rivers (Tapajós and Tocantins) in the Brazilian Amazon; to compare the trophic levels of these fish between the two methods (stable isotopes analysis and LEK) and the two rivers; and to develop diagrams representing the trophic webs of the main fish prey and predators based on fisher’s LEK. The fish species studied were Pescada (Plagioscion squamosissimus), Tucunaré (Cichla pinima), Piranha (Serrasalmus rhombeus), Aracu (Leporinus fasciatus), Charuto (Hemiodus unimaculatus), and Jaraqui (Semaprochilodus spp.). A total of 98 interviews and 63 samples for stable isotopes analysis were carried out in both rivers. The average fish trophic levels did not differ between the stable isotopes analysis and the LEK in the Tapajós, nor in the Tocantins Rivers. The overall trophic level of the studied fish species obtained through the LEK did not differ from data obtained through the stable isotopes analysis in both rivers, except for the Aracu in the Tapajós River. The main food items consumed by the fish according to fishers’ LEK did agree with fish diets as described in the biological literature. Fishers provided useful information on fish predators and feeding habits of endangered species, such as river dolphin and river otter. Collaboration with fishers through LEK studies can be a viable approach to produce reliable data on fish trophic ecology to improve fisheries management and species conservation in tropical freshwater environments and other regions with data limitations.

Trophic interactions in the Zoige Alpine wetland on the eastern edge of the Qinghai–Tibetan Plateau inferred by stable isotopes

Limnology ◽  
2018 ◽  
Vol 19 (3) ◽  
pp. 285-297 ◽  
Author(s):  
Bin Li ◽  
Fajun Chen ◽  
Dandan Xu ◽  
Zhijian Wang ◽  
Min Tao
Keyword(s):  
Stable Isotopes ◽  
Tibetan Plateau ◽  
Trophic Interactions ◽  
Alpine Wetland ◽  
Eastern Edge

Using stable isotopes to estimate the time since disconnection of pools in temporary rivers 

2021 ◽  
Author(s):  
Pilar Llorens ◽  
Sebastián González ◽  
Jérôme Latron ◽  
Cesc Múrria ◽  
Núria Bonada ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Isotopic Composition ◽  
River Flow ◽  
Meteorological Data ◽  
Global Network ◽  
Balance Model ◽  
Water Volume ◽  
Ecological Quality ◽  
Temporary Rivers ◽  
Hydrological Variable

<p>Temporary rivers, characterized by shifts between flowing water, disconnected pools and dry periods, represent over 50% of the world’s river network and future climatic projections suggest their increase. These rivers are understudied, especially when only disconnected pools remain, because gauging stations or hydrological models do not inform of what happens after the cessation of flow. In addition, most of biological indicators for water quality are designed for flowing waters and their adequacy for temporary rivers is uncertain.</p><p>The development of biological metrics adequate for the assessment of disconnected pools is difficult, because the high species replacement during and following flow cessation. For this reason, one hydrological variable of paramount importance for the assessment of ecological quality of disconected pools is the time since disconnection from the river flow.</p><p>The objective of our work is to present a methodology to estimate the time since disconnection of pools from the river flow. This methodology, following the Gonfiantini (1986) model, is based on the sampling of water stable isotopes in disconnected pools. For pools disconnected from the groundwater, knowing the isotopic modification of the water in time due to evaporation, allows to estimate the relative volume of water evaporated since the pool has been disconnected. However, this approach gets complicated when pools have relevant rainfall inputs or exchanges with groundwater.</p><p>Within the Vallcebre research area (42º12’N and 1º49’E), two artificial pools, one covered with a transparent lid to prevent the input of rainfall and another uncovered, were installed to validate this methodology in controlled conditions. From July to November 2020, water volume of these pools were weekly measured and sampled for isotopic analysis. In parallel, meteorological variables were monitored and rainfall was also sampled for water stable isotopes.</p><p>To develop and validate an operational methodology for estimating the time since disconnection, we first calculated the relative amount of evaporated water based on the variations of isotopic composition of the covered pool samples, and estimated the time since disconnection (for a given natural pool) using the potential evaporation calculated from the meteorological data. For the uncovered pool, the information of amount and isotopic composition of rainfall was added in a mass balance model. Additionally, the same estimations were calculated with standard information (i.e. the meteorological data obtained from the National Meteorological Service and precipitation isotopes data from the Global Network of Isotopes in Precipitation (GNIP) of the International Atomic Energy Agency). Finally, measured volumes changes in pools, were used to assess the limitations of the operational methodology and the sensitivity of the results to meteorological conditions.</p><p>Our approach suggests that changes in isotopic composition can be a reliable method to estimate time since disconnection of pools in temporary rivers to better assess their ecological quality.</p>

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