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 - Libuda, Lars A1 - Mesch, Christina M. A1 - Stimming, Madlen A1 - Demmelmair, Hans A1 - Koletzko, Berthold A1 - Warschburger, Petra A1 - Blanke, Katharina A1 - Reischl, Eva A1 - Kalhoff, Hermann A1 - Kersting, Mathilde T1 - Fatty acid supply with complementary foods and LC-PUFA status in healthy infants: results of a randomised controlled trial JF - European journal of nutrition N2 - Purpose Introduction of complementary food usually leads to decreasing intakes of long-chain n-3 polyunsaturated fatty acids (n-3 LC-PUFA), compared to full breast-feeding. In the randomised controlled PINGU intervention trial, we tested the effects of complementary foods with different contents of alpha-linolenic acid (ALA) and docosahexaenoic acid (DHA) on term infant LC-PUFA status. Methods Healthy infants born at term were randomised to receive from the introduction of complementary feeding at the age of 4 to 6 months until age of 10 months ready-made complementary meals either with ALA-rich rapeseed oil (intervention group (IG)-R), with salmon twice weekly to provide preformed DHA (IG-F), or with linoleic acid-rich corn oil (control group, CG). Fatty acid composition was assessed in erythrocyte (RBC) and plasma glycerophospholipids. Results Complete data of fatty acids in RBC (plasma) were available from 158 (155) infants. After intervention, infants assigned to IG-F showed higher RBC and plasma percentages of eicosapentaenoic acid (EPA), DHA, and total n-3 LC-PUFA than CG (each p < 0.001). In IG-R, levels of ALA and the ratio of ALA to LA in plasma and RBC (all p < 0.0001) as well as RBC-EPA (p < 0.0001) were higher than in CG, while DHA levels did not differ between IG-R and CG. Conclusions Regular fish consumption during complementary feeding enhances infant EPA and DHA status. The usage of rapeseed oil in small amounts concordant with EU-law for commercial meals enhances endogenic EPA-synthesis, but does not affect DHA status. Provision of oily fish with complementary feeds is advisable to prevent a decline of DHA status. Clinical Trial Registration www.clinicaltrials.gov, identifier: NCT01487889, title: Polyunsaturated fatty acids in child nutrition-a German multimodal optimisation study (PINGU). KW - DHA KW - Fish KW - Rapeseed oil KW - Complementary food KW - Complementary feeding KW - Alpha-linolenic acid KW - DHA status Y1 - 2016 U6 - https://doi.org/10.1007/s00394-015-0982-2 SN - 1436-6207 SN - 1436-6215 VL - 55 SP - 1633 EP - 1644 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Quintana, Xavier D. A1 - Arim, Matias A1 - Badosa, Anna A1 - Maria Blanco, Jose A1 - Boix, Dani A1 - Brucet, Sandra A1 - Compte, Jordi A1 - Egozcue, Juan J. A1 - de Eyto, Elvira A1 - Gaedke, Ursula A1 - Gascon, Stephanie A1 - Gil de Sola, Luis A1 - Irvine, Kenneth A1 - Jeppesen, Erik A1 - Lauridsen, Torben L. A1 - Lopez-Flores, Rocio A1 - Mehner, Thomas A1 - Romo, Susana A1 - Sondergaard, Martin T1 - Predation and competition effects on the size diversity of aquatic communities JF - Aquatic sciences : research across boundaries N2 - Body size has been widely recognised as a key factor determining community structure in ecosystems. We analysed size diversity patterns of phytoplankton, zooplankton and fish assemblages in 13 data sets from freshwater and marine sites with the aim to assess whether there is a general trend in the effect of predation and resource competition on body size distribution across a wide range of aquatic ecosystems. We used size diversity as a measure of the shape of size distribution. Size diversity was computed based on the Shannon-Wiener diversity expression, adapted to a continuous variable, i.e. as body size. Our results show that greater predation pressure was associated with reduced size diversity of prey at all trophic levels. In contrast, competition effects depended on the trophic level considered. At upper trophic levels (zooplankton and fish), size distributions were more diverse when potential resource availability was low, suggesting that competitive interactions for resources promote diversification of aquatic communities by size. This pattern was not found for phytoplankton size distributions where size diversity mostly increased with low zooplankton grazing and increasing nutrient availability. Relationships we found were weak, indicating that predation and competition are not the only determinants of size distribution. Our results suggest that predation pressure leads to accumulation of organisms in the less predated sizes, while resource competition tends to favour a wider size distribution. KW - Phytoplankton KW - Zooplankton KW - Fish KW - Size distribution KW - Predation KW - Competition KW - Compositional data analysis Y1 - 2015 U6 - https://doi.org/10.1007/s00027-014-0368-1 SN - 1015-1621 SN - 1420-9055 VL - 77 IS - 1 SP - 45 EP - 57 PB - Springer CY - Basel ER -