0000000001313659
AUTHOR
Jos Schilder
Variability in δ13C values between individual Daphnia ephippia: Implications for palaeo-studies
The stable carbon isotope ratio (δ13 C value) of Daphnia spp. resting egg shells (ephippia) provides information on past changes in Daphnia diet. Measurements are typically performed on samples of _20 ephippia, which obscures the range of values associated with individual ephippia. Using a recently developed laser ablation-based technique, we perform multiple δ13 C analyses on individual ephippia, which show a high degree of reproducibility (standard deviations 0.1e0.5‰). We further measured δ13 C values of 13 ephippia from surface sediments of three Swiss lakes. In the well-oxygenated lake with low methane concentrations, δ13 C values are close to values typical for algae (_31.4‰) and the …
Supplementary methods and results from Trophic state changes can affect the importance of methane-derived carbon in aquatic food webs
Additional details on methods and results (as referred to in the main article) and a semi-colon delimited table with downcore isotope and TP records
Abundance and δ13C values of fatty acids in lacustrine surface sediments: Relationships with in-lake methane concentrations
Proxy-indicators in lake sediments provide the only approach by which the dynamics of in-lake methane cycling can be examined on multi-decadal to centennial time scales. This information is necessary to constrain how lacustrine methane production, oxidation and emissions are expected to respond to global change drivers. Several of the available proxies for reconstructing methane cycle changes of lakes rely on interpreting past changes in the abundance or relevance of methane oxidizing bacteria (MOB), either directly (e.g. via analysis of bacterial lipids) or indirectly (e.g. via reconstructions of the past relevance of MOB in invertebrate diet). However, only limited information is availabl…
Carbon Budget and Molecular Structure of Natural Organic Matter in Bank Infiltrated Groundwater
Groundwater : : journal of the Association of Ground-Water Scientists and Engineers, a division of the National Ground Water Association (2021). doi:10.1111/gwat.13087
A Bayesian stable isotope mixing model for coping with multiple isotopes, multiple trophic steps and small sample sizes
We introduce a Bayesian stable isotope mixing model for estimating the relative contributions of different dietary components to the tissues of consumers within food webs. The model is implemented with the probabilistic programming language Stan. The model incorporates isotopes of multiple elements (e.g. C, N, H) for two trophic levels, when the structure of the food web is known. In addition, the model allows inclusion of latent trophic levels (i.e. for which no empirical data are available) intermediate between sources and measured consumers. Running the model in simulations driven by a real dataset from Finnish lakes, we tested the sensitivity of the posterior distributions by altering c…
Flotsam samples can help explain the δ13C and δ15N values of invertebrate resting stages in lake sediment
Abstract The stable isotopic composition of chitinous remains of Cladocera (water fleas) and freshwater Bryozoa (moss animals) preserved in lake sediment records can provide supporting insights into past environmental and ecosystem changes in lakes. Here we explore whether analyses of these remains isolated from lake flotsam can provide information on the driving variables affecting the isotopic composition of these remains. We collected flotsam in 53 lakes and found enough material in 33 lakes to measure the stable carbon and nitrogen isotope ratios (expressed as δ13C and δ15N values, respectively) of resting stages. These values were compared with lake characteristics, water chemistry mea…
Allochthony, fatty acid and mercury trends in muscle of Eurasian perch (Perca fluviatilis) along boreal environmental gradients
Environmental change, including joint effects of increasing dissolved organic carbon (DOC) and total phosphorus (TP) in boreal northern lakes could potentially affects food web energy sources and the biochemical composition of organisms. These environmental stressors are enhanced by anthropogenic land-use and can decrease the quality of polyunsaturated fatty acids (PUFAs) in seston and zooplankton, and therefore, possibly cascading up to fish. In contrast, the content of mercury in fish increases with lake browning potentially amplified by intensive forestry practises. However, there is little evidence on how these environmental stressors simultaneously impact beneficial omega-3 fatty acid …
Data for: Variability in δ13C values between individual Daphnia ephippia: Implications for palaeo-studies
Table providing the d13C values of individual Daphnia ephippia determined through laser ablation, nano combustion gas chromatography and isotope ratio mass spectrometry.