TY  - JOUR
A1  - Voigt, Christian C.
A1  - Kaiser, Klara
A1  - Look, Samantha
A1  - Scharnweber, Inga Kristin
A1  - Scholz, Carolin
T1  - Wind turbines without curtailment produce large numbers of bat fatalities throughout their lifetime
BT  - a call against ignorance and neglect
JF  - Global ecology and conservation
N2  - Bats are protected by national and international legislation in European countries, yet many species, particularly migratory aerial insectivores, collide with wind turbines which counteracts conservation efforts. Within the European Union it is legally required to curtail the operation of wind turbines at periods of high bat activity, yet this is not practiced at old wind turbines. Based on data from the national carcass repository in Germany and from our own carcass searches at a wind park with three turbines west of Berlin, we evaluated the magnitude of bat casualties at old, potentially poor-sited wind turbines operating without curtailment. We report 88 documented bat carcasses collected by various searchers over the 20-year operation period of this wind park from 2001 to 2021. Common noctule bats (Nyctalus noctula) and common pipistrelles (Pipistrellus pipistrellus) were most often found dead at these turbines. Our search campaign in August and September 2021 yielded a total of 18 carcasses. We estimated that at least 209 bats were likely killed during our field survey, yielding more than 70 casualties/wind turbine or 39 casualties/ MW in two months. Since our campaign covered only part of the migration season, we consider this value as an underestimate. The 20-year period of the wind park emphasises the substantial impact old turbines may have on bat individuals and populations when operating without curtailments. We call for reconsidering the operation procedures of old wind turbines to stop the continuous loss of bats in Germany and other countries where turbine curtailments are even less practiced than in Germany.
KW  - green-green dilemma
KW  - wind energy bat conflict
KW  - wildlife casualties
Y1  - 2022
U6  - https://doi.org/10.1016/j.gecco.2022.e02149
SN  - 2351-9894
VL  - 37
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Scharnweber, Inga Kristin
A1  - Chaguaceda, Fernando
A1  - Eklöv, Peter
T1  - Fatty acid accumulation in feeding types of a natural freshwater fish population
JF  - Oecologia / in cooperation with the International Association for Ecology, Intecol
N2  - Fatty acids are widely used to study trophic interactions in food web assemblages. Generally, it is assumed that there is a very small modification of fatty acids from one trophic step to another, making them suitable as trophic biomarkers. However, recent literature provides evidence that many fishes possess genes encoding enzymes with a role in bioconversion, thus the capability for bioconversion might be more widespread than previously assumed. Nonetheless, empirical evidence for biosynthesis occurring in natural populations remains scarce. In this study, we investigated different feeding types of perch (Perca fluviatilis) that are specialized on specific resources with different levels of highly unsaturated fatty acids (HUFAs), and analyzed the change between HUFA proportions in perch muscle tissue compared to their resources. Perch showed matching levels to their resources for EPA, but ARA and especially DHA were accumulated. Compound-specific stable isotope analyses helped us to identify the origin of HUFA carbon. Our results suggest that perch obtain a substantial amount of DHA via bioconversion when feeding on DHA-poor benthic resources. Thus, our data indicate the capability of bioconversion of HUFAs in a natural freshwater fish population.
KW  - Fatty acid conversion
KW  - Compound-specific stable isotope analysis
KW  - Docosahexaenoic acid
KW  - Bioconversion
KW  - Trophic upgrading
Y1  - 2021
U6  - https://doi.org/10.1007/s00442-021-04913-y
SN  - 0029-8549
SN  - 1432-1939
VL  - 196
IS  - 1
SP  - 53
EP  - 63
PB  - Springer
CY  - Berlin ; Heidelberg [u.a.]
ER  - 
TY  - JOUR
A1  - Scharnweber, Inga Kristin
A1  - Andersson, Matilda L.
A1  - Chaguaceda, Fernando
A1  - Eklöv, Peter
T1  - Intraspecific differences in metabolic rates shape carbon stable isotope trophic discrimination factors of muscle tissue in the common teleost Eurasian perch (Perca fluviatilis)
JF  - Ecology and evolution
N2  - Stable isotopes represent a unique approach to provide insights into the ecology of organisms. δ13C and δ15N have specifically been used to obtain information on the trophic ecology and food-web interactions. Trophic discrimination factors (TDF, Δ13C and Δ15N) describe the isotopic fractionation occurring from diet to consumer tissue, and these factors are critical for obtaining precise estimates within any application of δ13C and δ15N values. It is widely acknowledged that metabolism influences TDF, being responsible for different TDF between tissues of variable metabolic activity (e.g., liver vs. muscle tissue) or species body size (small vs. large). However, the connection between the variation of metabolism occurring within a single species during its ontogeny and TDF has rarely been considered. Here, we conducted a 9-month feeding experiment to report Δ13C and Δ15N of muscle and liver tissues for several weight classes of Eurasian perch (Perca fluviatilis), a widespread teleost often studied using stable isotopes, but without established TDF for feeding on a natural diet. In addition, we assessed the relationship between the standard metabolic rate (SMR) and TDF by measuring the oxygen consumption of the individuals. Our results showed a significant negative relationship of SMR with Δ13C, and a significant positive relationship of SMR with Δ15N of muscle tissue, but not with TDF of liver tissue. SMR varies inversely with size, which translated into a significantly different TDF of muscle tissue between size classes. In summary, our results emphasize the role of metabolism in shaping-specific TDF (i.e., Δ13C and Δ15N of muscle tissue) and especially highlight the substantial differences between individuals of different ontogenetic stages within a species. Our findings thus have direct implications for the use of stable isotope data and the applications of stable isotopes in food-web studies.
KW  - fractionation factors
KW  - metabolism
KW  - ontogeny
KW  - standard metabolic rate
KW  - tissue types
KW  - δ13C
KW  - δ15N
Y1  - 2021
SN  - 2045-7758
VL  - 11
IS  - 14
SP  - 9804
EP  - 9814
PB  - John Wiley & Sons, Inc.
CY  - New Jersey
ER  - 
TY  - GEN
A1  - Scharnweber, Inga Kristin
A1  - Andersson, Matilda L.
A1  - Chaguaceda, Fernando
A1  - Eklöv, Peter
T1  - Intra-specific differences in metabolic rates shape carbon stable isotope trophic discrimination factors of muscle tissue in the common teleost Eurasian perch (Perca fluviatilis)
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Stable isotopes represent a unique approach to provide insights into the ecology of organisms. δ13C and δ15N have specifically been used to obtain information on the trophic ecology and food-web interactions. Trophic discrimination factors (TDF, Δ13C and Δ15N) describe the isotopic fractionation occurring from diet to consumer tissue, and these factors are critical for obtaining precise estimates within any application of δ13C and δ15N values. It is widely acknowledged that metabolism influences TDF, being responsible for different TDF between tissues of variable metabolic activity (e.g., liver vs. muscle tissue) or species body size (small vs. large). However, the connection between the variation of metabolism occurring within a single species during its ontogeny and TDF has rarely been considered. Here, we conducted a 9-month feeding experiment to report Δ13C and Δ15N of muscle and liver tissues for several weight classes of Eurasian perch (Perca fluviatilis), a widespread teleost often studied using stable isotopes, but without established TDF for feeding on a natural diet. In addition, we assessed the relationship between the standard metabolic rate (SMR) and TDF by measuring the oxygen consumption of the individuals. Our results showed a significant negative relationship of SMR with Δ13C, and a significant positive relationship of SMR with Δ15N of muscle tissue, but not with TDF of liver tissue. SMR varies inversely with size, which translated into a significantly different TDF of muscle tissue between size classes. In summary, our results emphasize the role of metabolism in shaping-specific TDF (i.e., Δ13C and Δ15N of muscle tissue) and especially highlight the substantial differences between individuals of different ontogenetic stages within a species. Our findings thus have direct implications for the use of stable isotope data and the applications of stable isotopes in food-web studies.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1179 
KW  - fractionation factors
KW  - metabolism
KW  - ontogeny
KW  - standard metabolic rate
KW  - tissue types
KW  - δ13C
KW  - δ15N
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-524015
SN  - 1866-8372
IS  - 14
ER  - 
TY  - JOUR
A1  - Riesch, Rüdiger
A1  - Duwe, Virginia
A1  - Herrmann, Nina
A1  - Padur, Lisa
A1  - Ramm, Annemarie
A1  - Scharnweber, Inga Kristin
A1  - Schulte, Matthias
A1  - Schulz-Mirbach, Tanja
A1  - Ziege, Madlen
A1  - Plath, Martin
T1  - Variation along the shy-bold continuum in extremophile fishes (Poecilia mexicana, Poecilia sulphuraria)
N2  - One potential trade-off that bold individuals face is between increased predation risks and gains in resources. Individuals experiencing high predation and hungry individuals (or individuals with low body condition) are predicted to show increased boldness. We examined one behavioral trait previously reported to be associated with boldness (the time individual fish needed to emerge from shelter) in various populations of mollies (Poecilia spp.). Our study system included several southern Mexican surface streams with high piscine predation and high food availability, sulfidic surface streams with high avian predation, in which the inhabiting fish show reduced body condition, and a sulfidic cave, where predation and body condition are low. Our comparison revealed very short times to emerge from the start box in populations from non-sulfidic streams. In sulfidic habitats (whether surface or cave), it took individual Poecilia mexicana considerably longer to emerge from the start box, and the same difference was also found in an independent comparison between P. mexicana and the closely related, highly sulfide-adapted Poecilia sulphuraria. Fish reared under common garden conditions (in the absence of predators and hydrogen sulfide) showed intermediate boldness scores to the extremes observed in the field. Our data thus indicate that (a) boldness is shaped by environmental conditions/ experiential effects, but is not heritable, (b) predation affects boldness in the predicted direction, but (c) low body condition leads to reduced boldness. Extremophile Poecilia spp. spend most of their time surfacing to survive under sulfidic and hypoxic conditions, which exposes them to increased levels of predations, but the fish forage on the bottom. Hence, in this system, increased boldness does not increase foraging success. We argue that energy limitation favors reducing energetically costly behaviors, and exploring novel environments may be just one of them.
Y1  - 2009
UR  - http://www.springerlink.com/content/100464
U6  - https://doi.org/10.1007/s00265-009-0780-z
SN  - 0340-5443
ER  - 
TY  - JOUR
A1  - Mehner, Thomas
A1  - Lischke, Betty
A1  - Scharnweber, Inga Kristin
A1  - Attermeyer, Katrin
A1  - Brothers, Soren
A1  - Gaedke, Ursula
A1  - Hilt, Sabine
A1  - Brucet, Sandra
T1  - Empirical correspondence between trophic transfer efficiency in freshwater food webs and the slope of their size spectra
JF  - Ecology : a publication of the Ecological Society of America
N2  - The density of organisms declines with size, because larger organisms need more energy than smaller ones and energetic losses occur when larger organisms feed on smaller ones. A potential expression of density-size distributions are Normalized Biomass Size Spectra (NBSS), which plot the logarithm of biomass independent of taxonomy within bins of logarithmic organismal size, divided by the bin width. Theoretically, the NBSS slope of multi-trophic communities is exactly - 1.0 if the trophic transfer efficiency (TTE, ratio of production rates between adjacent trophic levels) is 10% and the predator-prey mass ratio (PPMR) is fixed at 10(4). Here we provide evidence from four multi-trophic lake food webs that empirically estimated TTEs correspond to empirically estimated slopes of the respective community NBSS. Each of the NBSS considered pelagic and benthic organisms spanning size ranges from bacteria to fish, all sampled over three seasons in 1 yr. The four NBSS slopes were significantly steeper than -1.0 (range -1.14 to -1.19, with 95% CIs excluding -1). The corresponding average TTEs were substantially lower than 10% in each of the four food webs (range 1.0% to 3.6%, mean 1.85%). The overall slope merging all biomass-size data pairs from the four systems (-1.17) was almost identical to the slope predicted from the arithmetic mean TTE of the four food webs (-1.18) assuming a constant PPMR of 10(4). Accordingly, our empirical data confirm the theoretically predicted quantitative relationship between TTE and the slope of the biomass-size distribution. Furthermore, we show that benthic and pelagic organisms can be merged into a community NBSS, but future studies have yet to explore potential differences in habitat-specific TTEs and PPMRs. We suggest that community NBSS may provide valuable information on the structure of food webs and their energetic pathways, and can result in improved accuracy of TTE-estimates.
KW  - energetic equivalence rule
KW  - metabolic theory of ecology
KW  - multi-trophic communities
KW  - normalized biomass size spectra
KW  - pelagic and benthic lake habitats
KW  - size of organisms
Y1  - 2018
U6  - https://doi.org/10.1002/ecy.2347
SN  - 0012-9658
SN  - 1939-9170
VL  - 99
IS  - 6
SP  - 1463
EP  - 1472
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Mehner, T.
A1  - Attermeyer, Katrin
A1  - Brauns, Mario
A1  - Brothers, Soren M.
A1  - Diekmann, J.
A1  - Gaedke, Ursula
A1  - Grossart, Hans-Peter
A1  - Koehler, J.
A1  - Lischke, Betty
A1  - Meyer, N.
A1  - Scharnweber, Inga Kristin
A1  - Syvaranta, J.
A1  - Vanni, M. J.
A1  - Hilt, S.
T1  - Weak Response of Animal Allochthony and Production to Enhanced Supply of
Terrestrial Leaf Litter in Nutrient-Rich Lakes
JF  - Ecosystems
N2  - Ecosystems are generally linked via fluxes of nutrients and energy across their boundaries. For example, freshwater ecosystems in temperate regions may receive significant inputs of terrestrially derived carbon via autumnal leaf litter. This terrestrial particulate organic carbon (POC) is hypothesized to subsidize animal production in lakes, but direct evidence is still lacking. We divided two small eutrophic lakes each into two sections and added isotopically distinct maize litter to the treatment sections to simulate increased terrestrial POC inputs via leaf litter in autumn. We quantified the reliance of aquatic consumers on terrestrial resources (allochthony) in the year subsequent to POC additions by applying mixing models of stable isotopes. We also estimated lake-wide carbon (C) balances to calculate the C flow to the production of the major aquatic consumer groups: benthic macroinvertebrates, crustacean zooplankton, and fish. The sum of secondary production of crustaceans and benthic macroinvertebrates supported by terrestrial POC was higher in the treatment sections of both lakes. In contrast, total secondary and tertiary production (supported by both autochthonous and allochthonous C) was higher in the reference than in the treatment sections of both lakes. Average aquatic consumer allochthony per lake section was 27-40%, although terrestrial POC contributed less than about 10% to total organic C supply to the lakes. The production of aquatic consumers incorporated less than 5% of the total organic C supply in both lakes, indicating a low ecological efficiency. We suggest that the consumption of terrestrial POC by aquatic consumers facilitates a strong coupling with the terrestrial environment. However, the high autochthonous production and the large pool of autochthonous detritus in these nutrient-rich lakes make terrestrial POC quantitatively unimportant for the C flows within food webs.
KW  - stable isotopes
KW  - terrestrial subsidy
KW  - carbon budget
KW  - ecological efficiency
KW  - benthic food web
KW  - pelagic food web
Y1  - 2016
U6  - https://doi.org/10.1007/s10021-015-9933-2
SN  - 1432-9840
SN  - 1435-0629
VL  - 19
SP  - 311
EP  - 325
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Lischke, Betty
A1  - Weithoff, Guntram
A1  - Wickham, Stephen A.
A1  - Attermeyer, Katrin
A1  - Großart, Hans-Peter
A1  - Scharnweber, Inga Kristin
A1  - Hilt, Sabine
A1  - Gaedke, Ursula
T1  - Large biomass of small feeders: ciliates may dominate herbivory in eutrophic lakes
JF  - Journal of plankton research
N2  - The importance of ciliates as herbivores and in biogeochemical cycles is increasingly recognized. An opportunity to observe the potential consequences of zooplankton dominated by ciliates arose when winter fish kills resulted in strong suppression of crustaceans by young planktivorous fish in two shallow lakes. On an annual average, ciliates made up 38-76% of the total zooplankton biomass in both lakes during two subsequent years. Consequently, ciliate biomass and their estimated grazing potential were extremely high compared with other lakes of various trophic states and depths. Grazing estimates based on abundance and size suggest that ciliates should have cleared the water column of small (<5 mu m) and intermediate (5-50 mu m) sized phytoplankton more than once a day. Especially, small feeders within the ciliates were important, likely exerting a strong top-down control on small phytoplankton. Particle-attached bacteria were presumably strongly suppressed by intermediate-sized ciliate feeders. In contrast to other lakes, large phytoplankton was proportionately very abundant. The phytoplankton community had a high evenness, which may be attributed to the feeding by numerous fast growing and selective ciliate species. Our study highlights ciliates as an important trophic link and adds to the growing awareness of the role of winter processes for plankton dynamics.
KW  - phytoplankton
KW  - crustaceans
KW  - rotifers
KW  - filtration rate
KW  - winter fish kill
Y1  - 2016
U6  - https://doi.org/10.1093/plankt/fbv102
SN  - 0142-7873
SN  - 1464-3774
VL  - 38
SP  - 2
EP  - 15
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Lischke, Betty
A1  - Mehner, Thomas
A1  - Hilt, Sabine
A1  - Attermeyer, Katrin
A1  - Brauns, Mario
A1  - Brothers, Soren M.
A1  - Grossart, Hans-Peter
A1  - Koehler, Jan
A1  - Scharnweber, Inga Kristin
A1  - Gaedke, Ursula
T1  - Benthic carbon is inefficiently transferred in the food webs of two eutrophic shallow lakes
JF  - Freshwater biology
N2  - The sum of benthic autotrophic and bacterial production often exceeds the sum of pelagic autotrophic and bacterial production, and hence may contribute substantially to whole-lake carbon fluxes, especially in shallow lakes. Furthermore, both benthic and pelagic autotrophic and bacterial production are highly edible and of sufficient nutritional quality for animal consumers. We thus hypothesised that pelagic and benthic transfer efficiencies (ratios of production at adjacent trophic levels) in shallow lakes should be similar. We performed whole ecosystem studies in two shallow lakes (3.5ha, mean depth 2m), one with and one without submerged macrophytes, and quantified pelagic and benthic biomass, production and transfer efficiencies for bacteria, phytoplankton, epipelon, epiphyton, macrophytes, zooplankton, macrozoobenthos and fish. We expected higher transfer efficiencies in the lake with macrophytes, because these provide shelter and food for macrozoobenthos and may thus enable a more efficient conversion of basal production to consumer production. In both lakes, the majority of the whole-lake autotrophic and bacterial production was provided by benthic organisms, but whole-lake primary consumer production mostly relied on pelagic autotrophic and bacterial production. Consequently, transfer efficiency of benthic autotrophic and bacterial production to macrozoobenthos production was an order of magnitude lower than the transfer efficiency of pelagic autotrophic and bacterial production to rotifer and crustacean production. Between-lake differences in transfer efficiencies were minor. We discuss several aspects potentially causing the unexpectedly low benthic transfer efficiencies, such as the food quality of producers, pelagic-benthic links, oxygen concentrations in the deeper lake areas and additional unaccounted consumer production by pelagic and benthic protozoa and meiobenthos at intermediate or top trophic levels. None of these processes convincingly explain the large differences between benthic and pelagic transfer efficiencies. Our data indicate that shallow eutrophic lakes, even with a major share of autotrophic and bacterial production in the benthic zone, can function as pelagic systems with respect to primary consumer production. We suggest that the benthic autotrophic production was mostly transferred to benthic bacterial production, which remained in the sediments, potentially cycling internally in a similar way to what has previously been described for the microbial loop in pelagic habitats. Understanding the energetics of whole-lake food webs, including the fate of the substantial benthic bacterial production, which is either mineralised at the sediment surface or permanently buried, has important implications for regional and global carbon cycling.
KW  - bacterial production
KW  - benthic food chain
KW  - pelagic food chain
KW  - quantitative food webs
KW  - trophic transfer efficiency
Y1  - 2017
U6  - https://doi.org/10.1111/fwb.12979
SN  - 0046-5070
SN  - 1365-2427
VL  - 62
SP  - 1693
EP  - 1706
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Hilt, Sabine
A1  - Wanke, Thomas
A1  - Scharnweber, Inga Kristin
A1  - Brauns, Mario
A1  - Syvaranta, Jari
A1  - Brothers, Soren M.
A1  - Gaedke, Ursula
A1  - Köhler, Jan
A1  - Lischke, Betty
A1  - Mehner, Thomas
T1  - Contrasting response of two shallow eutrophic cold temperate lakes to a partial winterkill of fish
JF  - Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica
N2  - Food-web effects of winterkill are difficult to predict as the enhanced mortality of planktivorous fish may be counterbalanced by an even higher mortality of piscivores. We hypothesised that a winterkill in a clear and a turbid shallow lake would equalise their fish community composition, but seasonal plankton successions would differ between lakes. After a partial winterkill, we observed a reduction of fish biomass by 16 and 43% in a clear-water and a turbid small temperate lake, respectively. Fish biomass and piscivore shares (5% of fish biomass) were similar in both lakes after this winterkill, but young-of-the-year (YOY) abundances were higher in the turbid lake. Top-down control by crustaceans was only partly responsible for low phytoplankton biomass at the end of May following the winterkill in both lakes. Summer phytoplankton biomass remained low in the clear-water lake despite high abundances of YOY fish (mainly roach). In contrast, the crustacean biomass of the turbid lake was reduced in summer by a high YOY abundance (sunbleak and roach), leading to a strong increase in phytoplankton biomass. The YOY abundance of fish in shallow eutrophic lakes may thus be more important for their summer phytoplankton development after winterkill than the relative abundance of piscivores.
KW  - Anoxia
KW  - Fish
KW  - Regime shifts
KW  - Roach
KW  - Shallow lakes
KW  - Submerged macrophytes
Y1  - 2015
U6  - https://doi.org/10.1007/s10750-014-2143-7
SN  - 0018-8158
SN  - 1573-5117
VL  - 749
IS  - 1
SP  - 31
EP  - 42
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Brothers, Soren M.
A1  - Koehler, J.
A1  - Attermeyer, Katrin
A1  - Grossart, Hans-Peter
A1  - Mehner, T.
A1  - Meyer, N.
A1  - Scharnweber, Inga Kristin
A1  - Hilt, Sabine
T1  - A feedback loop links brownification and anoxia in a temperate, shallow lake
JF  - Limnology and oceanography
N2  - This study examines a natural, rapid, fivefold increase in dissolved organic carbon (DOC) concentrations in a temperate shallow lake, describing the processes by which increased DOC resulted in anoxic conditions and altered existing carbon cycling pathways. High precipitation for two consecutive years led to rising water levels and the flooding of adjacent degraded peatlands. Leaching from the flooded soils provided an initial increase in DOC concentrations (from a 2010 mean of 12 +/- 1 mg L-1 to a maximum concentration of 53 mg L-1 by June 2012). Increasing water levels, DOC, and phytoplankton concentrations reduced light reaching the sediment surface, eliminating most benthic primary production and promoting anoxia in the hypolimnion. From January to June 2012 there was a sudden increase in total phosphorus (from 57 mg L-1 to 216 mg L-1), DOC (from 24.6 mg L-1 to 53 mg L-1), and iron (from 0.12 mg L-1 to 1.07 mg L-1) concentrations, without any further large fluxes in water levels. We suggest that anoxic conditions at the sediment surface and flooded soils produced a dramatic release of these chemicals that exacerbated brownification and eutrophication, creating anoxic conditions that persisted roughly 6 months below a water depth of 1 m and extended periodically to the water surface. This brownification-anoxia feedback loop resulted in a near-complete loss of macroinvertebrate and fish populations, and increased surface carbon dioxide (CO2) emissions by an order of magnitude relative to previous years.
Y1  - 2014
U6  - https://doi.org/10.4319/lo.2014.59.4.1388
SN  - 0024-3590
SN  - 1939-5590
VL  - 59
IS  - 4
SP  - 1388
EP  - 1398
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Brothers, Soren M.
A1  - Hilt, Sabine
A1  - Attermeyer, Katrin
A1  - Grossart, Hans-Peter
A1  - Kosten, Sarian
A1  - Lischke, Betty
A1  - Mehner, Thomas
A1  - Meyer, Nils
A1  - Scharnweber, Inga Kristin
A1  - Köhler, Jan
T1  - A regime shift from macrophyte to phytoplankton dominance enhances carbon burial in a shallow, eutrophic lake
JF  - Ecosphere : the magazine of the International Ecology University
N2  - Ecological regime shifts and carbon cycling in aquatic systems have both been subject to increasing attention in recent years, yet the direct connection between these topics has remained poorly understood. A four-fold increase in sedimentation rates was observed within the past 50 years in a shallow eutrophic lake with no surface in-or outflows. This change coincided with an ecological regime shift involving the complete loss of submerged macrophytes, leading to a more turbid, phytoplankton-dominated state. To determine whether the increase in carbon (C) burial resulted from a comprehensive transformation of C cycling pathways in parallel to this regime shift, we compared the annual C balances (mass balance and ecosystem budget) of this turbid lake to a similar nearby lake with submerged macrophytes, a higher transparency, and similar nutrient concentrations. C balances indicated that roughly 80% of the C input was permanently buried in the turbid lake sediments, compared to 40% in the clearer macrophyte-dominated lake. This was due to a higher measured C burial efficiency in the turbid lake, which could be explained by lower benthic C mineralization rates. These lower mineralization rates were associated with a decrease in benthic oxygen availability coinciding with the loss of submerged macrophytes. In contrast to previous assumptions that a regime shift to phytoplankton dominance decreases lake heterotrophy by boosting whole-lake primary production, our results suggest that an equivalent net metabolic shift may also result from lower C mineralization rates in a shallow, turbid lake. The widespread occurrence of such shifts may thus fundamentally alter the role of shallow lakes in the global C cycle, away from channeling terrestrial C to the atmosphere and towards burying an increasing amount of C.
KW  - calcite precipitation
KW  - CO2 emissions
KW  - global carbon cycle
KW  - metabolism
KW  - regime shift
KW  - sedimentation
KW  - submerged macrophytes
KW  - temperate zone
KW  - trophic status
Y1  - 2013
U6  - https://doi.org/10.1890/ES13-00247.1
SN  - 2150-8925
VL  - 4
IS  - 11
PB  - Wiley
CY  - Washington
ER  - 
TY  - JOUR
A1  - Andersson, Matilda L.
A1  - Scharnweber, Inga Kristin
A1  - Eklöv, Peter
T1  - The interaction between metabolic rate, habitat choice, and resource use in a polymorphic freshwater species
JF  - Ecology and evolution
N2  - Resource polymorphism is common across taxa and can result in alternate ecotypes with specific morphologies, feeding modes, and behaviors that increase performance in a specific habitat. This can result in high intraspecific variation in the expression of specific traits and the extent to which these traits are correlated within a single population. Although metabolic rate influences resource acquisition and the overall pace of life of individuals it is not clear how metabolic rate interacts with the larger suite of traits to ultimately determine individual fitness. We examined the relationship between metabolic rates and the major differences (habitat use, morphology, and resource use) between littoral and pelagic ecotypes of European perch (Perca fluviatilis) from a single lake in Central Sweden. Standard metabolic rate (SMR) was significantly higher in pelagic perch but did not correlate with resource use or morphology. Maximum metabolic rate (MMR) was not correlated with any of our explanatory variables or with SMR. Aerobic scope (AS) showed the same pattern as SMR, differing across habitats, but contrary to expectations, was lower in pelagic perch. This study helps to establish a framework for future experiments further exploring the drivers of intraspecific differences in metabolism. In addition, since metabolic rates scale with temperature and determine predator energy requirements, our observed differences in SMR across habitats will help determine ecotype-specific vulnerabilities to climate change and differences in top-down predation pressure across habitats.
KW  - intraspecific variation
KW  - metabolic rate
KW  - morphometrics
KW  - Perca
KW  - fluviatilis
KW  - plasticity
KW  - resource use
KW  - respirometry
KW  - stable isotopes
Y1  - 2022
U6  - https://doi.org/10.1002/ece3.9129
SN  - 2045-7758
VL  - 12
IS  - 8
PB  - Wiley
CY  - Hoboken
ER  -