Biederbick, J., Möllmann, C., Hauten, E., Russnak, V., Lahajnar, N., Hansen, T., Dierking, J. , Koppelmann, R. and Ji, R. (2025) Spatial and temporal patterns of zooplankton trophic interactions and carbon sources in the eutrophic Elbe estuary (Germany). ICES Journal of Marine Science, 82 (5). Art.Nr.: fsae189. DOI 10.1093/icesjms/fsae189.

Matthiessen, B. , Hattich, G. S. I., Pulina, S., Hansen, T., Reusch, T. B. H. and Hamer, J. (2025) Phytoplankton mean cell size and total biomass increase with nutrients are driven by both species composition and evolution of plasticity. Oikos, 2025 (1). Art.Nr.: e10910. DOI 10.1111/oik.10910.

Ito, M. , Guy-Haim, T., Sawall, Y., Franz, M. , Buchholz, B., Hansen, T., Neitzel, P., Pansch, C., Steinhoff, T. , Wahl, M. , Weinberger, F. and Scotti, M. (2024) Responses at various levels of ecological hierarchy indicate acclimation to sequential sublethal heatwaves in a temperate benthic ecosystem. Philosophical Transactions of the Royal Society B: Biological Sciences, 379 (1909). Art.Nr. 20230171. DOI 10.1098/rstb.2023.0171.

Priester, C. R., Dierking, J. , Hansen, T., Abecasis, D., Fontes, J. M. and Afonso, P. (2024) Trophic ecology and coastal niche partitioning of two sympatric shark species in the Azores (mid-Atlantic). Marine Ecology Progress Series, 726 . pp. 113-130. DOI 10.3354/meps14487.

Bonnet-Lebrun, A. S., Larsen, T., Thórarinsson, T. L., Kolbeinsson, Y., Frederiksen, M., Morley, T. I., Fox, D., Boutet, A., le Bouard, F., Deville, T., Hansen, E. S., Hansen, T., Roberts, P. and Ratcliffe, N. (2022) Cold comfort: Arctic seabirds find refugia from climate change and potential competition in marginal ice zones and fjords. Ambio, 51 . pp. 345-354. DOI 10.1007/s13280-021-01650-7.

Djeghri, N., Pondaven, P., Le Grand, F., Bideau, A., Duquesne, N., Stockenreiter, M., Behl, S., Huang, J. Y. T., Hansen, T., Patris, S., Ucharm, G. and Stibor, H. (2021) High trophic plasticity in the mixotrophic Mastigias papua-Symbiodiniaceae holobiont: implications for the ecology of zooxanthellate jellyfishes. Marine Ecology Progress Series, 666 . pp. 73-88. DOI 10.3354/meps13707.

Chi, X. , Dierking, J. , Hoving, H. J. T. , Lüskow, F., Denda, A., Christiansen, B., Sommer, U., Hansen, T. and Javidpour, J. (2021) Tackling the jelly web: Trophic ecology of gelatinous zooplankton in oceanic food webs of the eastern tropical Atlantic assessed by stable isotope analysis. Limnology and Oceanography, 66 (2). pp. 289-305. DOI 10.1002/lno.11605.

Djeghri, N., Pondaven, P., Stockenreiter, M., Behl, S., Huang, J. Y. T., Hansen, T., Patris, S., Ucharm, G. and Stibor, H. (2020) Isotopic and elemental compositions reveal density‐dependent nutrition pathways in a population of mixotrophic jellyfish. Ecosphere, 11 (11). Art.NR. e03295. DOI 10.1002/ecs2.3295.

Larsen, T. , Hansen, T. and Dierking, J. (2020) Characterizing niche differentiation among marine consumers with amino acid δ 13 C fingerprinting . Ecology and Evolution, 10 (14). pp. 7768-7782. DOI 10.1002/ece3.6502.

Burian, A. , Nielsen, J. M., Hansen, T., Bermudez, R. and Winder, M. (2020) The potential of fatty acid isotopes to trace trophic transfer in aquatic food-webs. Philosophical Transactions of the Royal Society B: Biological Sciences, 375 (1804). p. 20190652. DOI 10.1098/rstb.2019.0652.

Winder, M., Bouquet, J. M., Bermudez, J. R., Berger, S. A., Hansen, T., Brandes, J., Sazhin, A. F., Nejstgaard, J. C., Båmstedt, U., Jakobsen, H. H., Dutz, J., Frischer, M. E., Troedsson, C. and Thompson, E. M. (2017) Increased appendicularian zooplankton alter carbon cycling under warmer more acidified ocean conditions. Limnology and Oceanography, 62 (4). pp. 1541-1551. DOI 10.1002/lno.10516.

Garzke, J., Hansen, T., Ismar, S. M. H. and Sommer, U. (2016) Combined Effects of Ocean Warming and Acidification on Copepod Abundance, Body Size and Fatty Acid Content. PLoS ONE, 11 (5). e0155952. DOI 10.1371/journal.pone.0155952.

Kürten, B., Al-Aidaroos, A. M., Kürten, S., El-Sherbiny, M. M., Devassy, R. P., Struck, U., Zarokanellos, N., Jones, B. H., Hansen, T., Bruss, G. and Sommer, U. (2016) Carbon and nitrogen stable isotope ratios of pelagic zooplankton elucidate ecohydrographic features in the oligotrophic Red Sea. Progress in Oceanography, 140 . pp. 69-90. DOI 10.1016/j.pocean.2015.11.003.

Mittermayr, A., Hansen, T. and Sommer, U. (2014) Simultaneous analysis of δ13C, δ15N and δ34S ratios uncovers food web relationships and the trophic importance of epiphytes in an eelgrass, Zostera marina community. Marine Ecology Progress Series, 497 . pp. 93-103. DOI 10.3354/meps10569.

Hansen, T., Gardeler, B. and Matthiessen, B. (2013) Technical Note: Precise quantitative measurements of total dissolved inorganic carbon from small amounts of seawater using a gas chromatographic system. Biogeosciences (BG), 10 (10). pp. 6601-6608. DOI 10.5194/bg-10-6601-2013.

Hauss, H. , Franz, J., Hansen, T., Struck, U. and Sommer, U. (2013) Relative inputs of upwelled and atmospheric nitrogen to the eastern tropical North Atlantic food web: Spatial distribution of δ15N in mesozooplankton and relation to dissolved nutrient dynamics. Deep Sea Research Part I: Oceanographic Research Papers, 75 . pp. 135-145. DOI 10.1016/j.dsr.2013.01.010.

Aberle, N., Hansen, T., Böttger-Schnack, R. , Burmeister, A., Post, A. F. and Sommer, U. (2010) Differential routing of "new" nitrogen towards higher trophic levels within the marine food web of the Gulf of Aqaba, northern Red Sea. Marine Biology, 157 . pp. 157-169. DOI 10.1007/s00227-009-1306-y.

Hansen, T., Burmeister, A. and Sommer, U. (2009) Simultaneous δ15N, δ13C and δ34S measurements of low-biomass samples using a technically advanced high sensitivity elemental analyzer connected to an isoptope ratio mass spectrometer. Rapid Communications in Mass Spectrometry, 23 (21). pp. 3387-3393. DOI 10.1002/rcm.4267.

Javidpour, J. , Molinero, J. C., Lehmann, A., Hansen, T. and Sommer, U. (2009) Annual assessment of the predation of Mnemiopsis leidyi in a new invaded environment, the Kiel Fjord (Western Baltic Sea): a matter of concern?. Journal of Plankton Research, 31 (7). pp. 729-738. DOI 10.1093/plankt/fbp021.

Ismar, S. M. H. , Hansen, T. and Sommer, U. (2008) Effect of food concentration and type of diet on Acartia survival and naupliar development. Marine Biology, 154 . pp. 335-343. DOI 10.1007/s00227-008-0928-9.

Jaschinski, S., Hansen, T. and Sommer, U. (2008) Effects of Acidification in multiple stable Isotope Analyses. Limnology and Oceanography: Methods, 6 . pp. 12-15. DOI 10.4319/lom.2008.6.12.

Hansen, T. and Sommer, U. (2007) Increasing the sensitivity of delta¹³C and delta¹⁵N abundance measurements by a high sensitivity elemental analyzer connected to an isotope ratio mass spectrometer. Rapid Communications in Mass Spectrometry, 21 (3). pp. 314-318. DOI 10.1002/rcm.2847.

Sommer, U., Aberle, N., Engel, A. , Hansen, T., Lengfellner, K., Sandow, M., Wohlers, J., Zöllner, E. and Riebesell, U. (2007) An indoor mesocosm system to study the effect of climate change on the late winter and spring succession of Baltic Sea phyto- and zooplankton. Oecologia, 150 (4). pp. 655-667. DOI 10.1007/s00442-006-0539-4.

Flöder, S., Hansen, T. and Ptacnik, R. (2006) Energy-Dependent Bacterivory in Ochromonas minima - A Strategy Promoting the Use of Substitutable Ressources and Survival at Insufficient Light Supply. Protist, 157 (3). pp. 291-302. DOI 10.1016/j.protis.2006.05.002.

Sommer, F., Hansen, T. and Sommer, U. (2006) Transfer of diazotrophic nitrogen to mesozooplankton in Kiel Fjord, Western Baltic Sea: a mesocosm study. Marine Ecology Progress Series, 324 . pp. 105-112. DOI 10.3354/meps324105.

Sommer, F., Saage, A., Santer, B., Hansen, T. and Sommer, U. (2005) Linking foraging strategies of marine calanoid copepods to patterns of nitrogen stable isotope signatures in a mesocosm study. Marine Ecology Progress Series, 286 . pp. 99-106. DOI 10.3354/meps286099.

Sommer, U., Hansen, T., Blum, O., Holzner, N., Vadstein, O. and Stibor, H. (2005) Copepod and microzooplankton grazing in mesocosms fertilised with different Si:N ratios: no overlap between food spectra and Si:N influence on zooplankton trophic level. Oecologia, 142 . pp. 274-283. DOI 10.1007/s00442-004-1708-y.

Katechakis, A., Stibor, H., Sommer, U. and Hansen, T. (2004) Feeding selectivities and food niche separation of Acartia clausi, Penilia avirostris (Crustacea) and Doliolum denticulatum (Thaliacea) in Blanes Bay (Catalan Sea, NW Mediterranean). Journal of Plankton Research, 26 . pp. 589-603. DOI 10.1093/plankt/fbh062.

Ptacnik, R., Sommer, U., Hansen, T. and Martens, V. (2004) Effects of microzooplankton and mixotrophy in an experimental planktonic food web. Limnology and Oceanography, 49 . pp. 1435-1445. DOI 10.4319/lo.2004.49.4_part_2.1435.

Sommer, U., Hansen, T., Stibor, H. and Vadstein, O. (2004) Persistence of phytoplankton responses to different Si:N ratios under mesozooplankton grazing pressure: a mesocosm study with Northeast Atlantic plankton. Marine Ecology Progress Series, 278 . pp. 67-75. DOI 10.3354/meps278067.

Sommer, U., Sommer, F., Feuchtmayr, H. and Hansen, T. (2004) The influence of mesozooplankton on phytoplankton nutrient limitation: A mesocosm study with northeast Atlantic phytoplankton. Protist, 155 . pp. 295-304. DOI 10.1078/1434461041844268.

Stibor, H., Vadstein, O., Diehl, S., Gelzleichter, A., Hansen, T., Hantzsche, F., Katechakis, A., Lippert, B., Loeseth, K., Petersen, C., Roederer, W., Sandow, M., Sundt-Hansen, L. and Olsen, Y. (2004) Copepods act as switch between alternative trophic cascades in marine pelagic food webs. Ecology Letters, 7 (4). pp. 321-328. DOI 10.1111/j.1461-0248.2004.00580.x.

Sommer, F., Hansen, T., Feuchtmayr, H., Santer, B., Tokle, N. and Sommer, U. (2003) Do calanoid copepods supress appendicularians in the coastal ocean?. Journal of Plankton Research, 25 . pp. 869-871. DOI 10.1093/plankt/25.7.869.

Sommer, F., Santer, B., Jamieson, C., Hansen, T. and Sommer, U. (2003) Daphnia population growth but not moulting is a substantial phosphorus drain for phytoplankton. Freshwater Biology, 48 (1). pp. 67-74.

Katechakis, A., Stibor, H., Sommer, U. and Hansen, T. (2002) Changes in the plankton community and the microbial food web of Blanes bay (Catalan Sea. NW Mediterranean) under prolonged grazing pressure by doliolids (Tunicata), cladocerans and copepods (Crustacea). Marine Ecology Progress Series, 234 . pp. 55-69. DOI 10.3354/meps234055.

Sommer, U., Berninger, U. G., Böttger-Schnack, R. , Cornils, A., Hagen, W., Hansen, T., Al-Najjar, T., Post, A. F., Schnack-Schiel, S. B., Stibor, H., Stübing, D. and Wickham, S. (2002) Grazing during the spring bloom in the Gulf of Aquaba and the Northern Red Sea. Marine Ecology Progress Series, 239 . pp. 251-261. DOI 10.3354/meps239251.

Sommer, U., Sommer, F., Santer, B., Jamieson, C., Boersma, M., Becker, C. and Hansen, T. (2001) Complementary impact of copepods and cladocerans on phytoplankton. Ecology Letters, 4 (6). pp. 545-550. DOI 10.1046/j.1461-0248.2001.00263.x.

Sommer, U., Stibor, H., Katechakis, A., Sommer, F. and Hansen, T. (2002) Pelagic food web configurations at different levels of nutrient richness and their implications for the ratio fish production: primary production. In: Sustainable Increase of Marine Harvesting: Fundamental Mechanisms and New Concepts: Proceedings of the 1 st Maricult Conference held in Trondheim, Norway, 25-28 June 2000. , ed. by Vadstein, O. and Olsen, Y.. Developments in Hydrobiology, 167 . Springer, Berlin, Germany, pp. 11-20. ISBN 978-90-481-6217-8 DOI 10.1007/978-94-017-3190-4_2.

Lengfellner, K., Aberle, N., Sandow, M., Hansen, T. and Sommer, U. (2006) The impact of climate change on plankton spring succession: a mesocosm study. [Talk] In: ASLO 2006 Summer Meeting. , 05.06, Victoria, British Columbia, Canada .

Agurto, C., Sommer, F., Sommer, U. and Hansen, T. (2005) Assessing trophic levels of mesozooplankton in the central Baltic Sea and North Sea: a stable isotope study. [Other] In: UNSPECIFIED. , 03.10, Valdivia, Chile .

Agurto, C., Sommer, F., Sommer, U., Hansen, T. and Rautenstrauch, C. (2005) Stable isotope (δ¹³C and ¹⁵N signatures analyses) signatures of mesozooplankton and seston size fractions at the Central Baltic Sea: Bornholm Basin. [Other] In: FE Seminar. , 02.09, Kiel .

Agurto, C., Sommer, F., Sommer, U., Hansen, T. and Rautenstrauch, C. (2005) Trophic structure of mesozooplankton in the Central Baltic Sea: δ¹³C and ¹⁵N signatures analysis. [Other] In: Cycle of Conferences in Oceanography. , 24.01, Concepción, Chile .

Lengfellner, K., Aberle, N., Sandow, M., Hansen, T. and Sommer, U. (2005) Plankton spring succession in response to warming winters. [Other] In: 2. AQUASHIFT Workshop. , 28.09.2005, Kiel .

Mittermayr, A. and Hansen, T. (2014) Tracing eelgrass foodwebs: simultaneous analysis of d13C, d15N and d34S of low biomass samples. [Poster] In: Advances in Stable Isotope Techniques and Applications (ASITA). , 15.-18.06.2014, Davis, CA, USA .

Ismar, S. M. H. , Lengfellner, K., Hansen, T. and Sommer, U. (2006) Climate change impacts on the autumn succession of phytoplankton: an experimental analysis with Baltic Sea plankton. [Poster] In: ASTRA Conference Are we prepared to cope with climate changes?- Consequences of the winter storm 2005. , 18.-19.05.2006, Klaipeda, Lithuania .

Wallace, D. W. R., Tanhua, T. , Banyte, D., Dippe, T., Karbe, F. R., Link, R., Silva, P., Franz, J., Hansen, T., Hauss, H. , Nachtigall, K., Franzke, D., Fuessel, J., Kalvelage, T., Fischer, T. , Gill, D., Kock, A. , Stange, K., Baars, O., Dammshäuser, A., Manke, A., Noll, L., Syre, S., Zocher, J. and Raeke, A. (2013) Guinea Upwelling Tracer Release Experiment – Cruise No. M80/2 – November 26 – December 22, 2009 – Mindelo (Cape Verde) – Dakar (Senegal). . Meteor-Berichte, M80/2 . UNSPECIFIED, 33 pp. DOI 10.2312/cr_m80_2.