Effects of ethanol-preservation on stable carbon and nitrogen isotopic signatures in marine predators

Chemical preservatives (e.g. mercuric chloride) are routinely added to freshwater samples to prevent biological activity compromising the isotopic signature of dissolved organic matter (DOM) with time. However, alternative preservation methods are needed due to regulations restricting the use of preservatives with potentially adverse environmental and health impacts, rendering such additions unviable. This study investigates whether a non-chemical storage method is sufficient to maintain the radiocarbon and stable carbon and nitrogen signatures of freshwater DOM from a low order river system draining a peaty catchment. Some 50 L of stream water were collected in 1 plastic carbuoy and, within 24 hr, 1-L aliquots were transferred to acid-washed plastic bottles. Five aliquots were analyzed immediately to determine the baseline values for 14C (pMC), δ13C (VPDB‰), δ15N (AIR‰), %C (mg L–1), and %N (mg L–1). Of the remaining subsamples, 20 were frozen and a further 20 refrigerated at <4 °C. After 7, 30, 90, and 180 days, 5 frozen and 5 refrigerated aliquots were analyzed in the same manner as the baseline aliquots. Analysis of the results shows that there is no statistically significant interaction between the variables storage method or length of storage for any of the determinants. Storage method has a statistically significant effect on 14C (pMC) and [C] (mg L–1). Length of storage has a statistically significant effect on δ13C (VPDB‰), [C] (mg L–1), and [N] (mg L–1) values. Neither storage method nor length of storage appear to have a statistically significant effect on 815N (AIR‰) values.

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Trophic structure of the macrobenthic community of Hornsund, Spitsbergen, based on the determination of stable carbon and nitrogen isotopic signatures

Polar Biology ◽

10.1007/s00300-014-1517-7 ◽

2014 ◽

Vol 37 (9) ◽

pp. 1247-1260 ◽

Cited By ~ 13

Author(s):

A. Sokołowski ◽

A. Szczepańska ◽

P. Richard ◽

M. Kędra ◽

M. Wołowicz ◽

...

Keyword(s):

Trophic Structure ◽

Macrobenthic Community ◽

Stable Carbon ◽

Isotopic Signatures ◽

Carbon And Nitrogen

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Applying isotopic clocks to identify prior migration patterns and critical habitats in mobile marine predators

Conservation Physiology ◽

10.1093/oso/9780198843610.003.0005 ◽

2020 ◽

pp. 69-86

Author(s):

Daniel J. Madigan ◽

Oliver N. Shipley ◽

Nigel E. Hussey

Keyword(s):

Large Scale ◽

Marine Species ◽

Turnover Rates ◽

Migration Patterns ◽

Isotopic Signatures ◽

Carbon And Nitrogen ◽

Migration Timing ◽

Marine Predators ◽

Mobile Species ◽

Management And Conservation

Large-scale migrations present challenges to management of exploited or at-risk marine species. Our understanding of predator movements has greatly improved, but data are often inadequate to understand patterns on population scales. The chemical composition of predator tissues, most often stable isotope ratios of carbon and nitrogen (δ‎13C and δ‎15N), provides markers of movement as predators incorporate discrete regional isotopic signatures throughout their migratory pathways. These signals can be analysed from small quantities of various tissues (e.g. muscle, liver, blood, hair, feathers) all of which provide different timescales of movement. Predator physiology mediates the assimilation and turnover rates of stable isotopes in tissues, providing a temporal element to interpretation of predator isotopic signatures. Combining physiology-mediated isotopic turnover rates and geographic ‘isoscapes’ of regional isotopic gradients allows for isotopic clock estimates of predator migration timing, which can be used to generate population-scale estimates of retrospective movements using large datasets across targeted regions and sampling periods. This allows for improved regional and international management and conservation of mobile species across their migratory ranges.

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STABLE CARBON AND NITROGEN ISOTOPES OF HARDWOOD FOREST AND THE PINE BARRENS IN NEW JERSEY

10.1130/abs/2020se-344267 ◽

2020 ◽

Author(s):

Antonio R. Justiniano ◽

◽

Ying Cui

Keyword(s):

New Jersey ◽

Nitrogen Isotopes ◽

Hardwood Forest ◽

Pine Barrens ◽

Stable Carbon ◽

Carbon And Nitrogen Isotopes ◽

Carbon And Nitrogen

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Stable carbon and nitrogen isotopic characterization and tracing nutrient sources of Ulva blooms around Jeju coastal areas

Environmental Pollution ◽

10.1016/j.envpol.2019.113033 ◽

2019 ◽

Vol 254 ◽

pp. 113033 ◽

Cited By ~ 3

Author(s):

Palas Samanta ◽

Sookkyung Shin ◽

Sojin Jang ◽

Young-Cheol Song ◽

Sangsil Oh ◽

...

Keyword(s):

Coastal Areas ◽

Stable Carbon ◽

Nutrient Sources ◽

Carbon And Nitrogen ◽

Isotopic Characterization

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Biosignatures of ancient microbial life are present across the igneous crust of the Fennoscandian shield

Communications Earth & Environment ◽

10.1038/s43247-021-00170-2 ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Henrik Drake ◽

Nick M. W. Roberts ◽

Manuel Reinhardt ◽

Martin Whitehouse ◽

Magnus Ivarsson ◽

...

Keyword(s):

Fennoscandian Shield ◽

Stable Carbon ◽

Deep Biosphere ◽

Isotopic Signatures ◽

Microbial Life ◽

Carbon Isotopic ◽

Terrestrial Life ◽

Vein Mineral ◽

Methyl Branched Fatty Acids

AbstractEarth’s crust contains a substantial proportion of global biomass, hosting microbial life up to several kilometers depth. Yet, knowledge of the evolution and extent of life in this environment remains elusive and patchy. Here we present isotopic, molecular and morphological signatures for deep ancient life in vein mineral specimens from mines distributed across the Precambrian Fennoscandian shield. Stable carbon isotopic signatures of calcite indicate microbial methanogenesis. In addition, sulfur isotope variability in pyrite, supported by stable carbon isotopic signatures of methyl-branched fatty acids, suggest subsequent bacterial sulfate reduction. Carbonate geochronology constrains the timing of these processes to the Cenozoic. We suggest that signatures of an ancient deep biosphere and long-term microbial activity are present throughout this shield. We suggest that microbes may have been active in the continental igneous crust over geological timescales, and that subsurface investigations may be valuable in the search for extra-terrestrial life.

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