Aberle, N. ; Hansen, Thomas ; Boettger-Schnack, Ruth ; Burmeister, Angela ; Sommer, Ulrich:
Differential routing of "new" nitrogen towards higher trophic levels within the marine food web of the Gulf of Aqaba, northern Red Sea .
In: Marine biology 157 (2010), S. 157-169
Stichwörter:  [FB3/EOE-N]; [FB2/BI]
[doi>10.1007/s00227-009-1306-y]

Javidpour, Jamileh ; Molinero, Juan Carlos ; Lehmann, Andreas ; Hansen, Thomas ; Sommer, Ulrich:
Annual assessment of the predation of Mnemiopsis leidyi in a new invaded environment, the Kiel Fjord (Western Baltic Sea): a matter of concern?
In: Journal of Plankton Research 31 (2009), Nr. 7, S. 729-738
Stichwörter:  [FB3/EOE-N]; [FB1/TM]
[doi>10.1093/plankt/fbp021]

Hansen, Thomas ; Burmeister, Angela ; Sommer, Ulrich:
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 .
In: Rapid Communications in Mass Spectrometry 23 (2009), Nr. 21, S. 3387-3393; 10.1002/rcm.4267
Stichwörter:  [FB3/EOE-N]; [FB3/EV]

Ismar, S. ; Hansen, Thomas ; Sommer, Ulrich:
Effect of food concentration and type of diet on Acartia survival and naupliar development .
In: Marine Biology 154 (2008), S. 335-343
Stichwörter:  [FB3/EOE-N]
[doi>10.1007/s00227-008-0928-9]

Jaschinski, Sybill ; Hansen, Thomas ; Sommer, Ulrich:
Effects of Acidification in multiple stable Isotope Analyses .
In: Limnology and Oceanography Methods 6 (2008), S. 12-15
Stichwörter:  [FB3/EOE-N]

Sommer, Ulrich ; Aberle-Malzahn, Nicole ; Engel, A. ; Hansen, Thomas ; Lengfellner, Kathrin ; Sandow, Marcel ; Wohlers, Julia ; Zöllner, Eckart ; Riebesell, Ulf:
An indoor mesocosm system to study the effect of climate change on the late winter and spring succession of Baltic Sea phyto- and zooplankton .
In: Oecologia 150 (2007), Nr. 4, S. 655-667
Stichwörter:  [FB3/EOE-N]; [FB2/BI]; [FB2/CH]
[doi>10.1007/s00442-006-0539-4]

Hansen, Thomas ; Sommer, Ulrich:
Increasing the sensitivity of delta¹³C and delta¹⁵N abundance measurements by a high sensitivity elemental analyzer connected to an isotope ratio mass spectrometer. .
In: Rapid Commun Mass Spectrom (2007), Nr. 21, S. 314-318
Stichwörter:  [FB3/EOE-N]

Flöder, S. ; Hansen, Thomas ; Ptacnik, R. :
Energy-Dependent Bacterivory in Ochromonas minima - A Strategy Promoting the Use of Substitutable Ressources and Survival at Insufficient Light Supply .
In: Protist 157 (2006), Nr. 3, S. 291-302
Stichwörter:  [FB3/EO1]
[doi>10.1016/j.protis.2006.05.002]

Sommer, Frank ; Hansen, Thomas ; Sommer, Ulrich:
Transfer of diazotrophic nitrogen to mesozooplankton in Kiel Fjord, Western Baltic Sea: a mesocosm study. .
In: Marine Ecology Progress Series 324 (2006), S. 105-112
Stichwörter:  [FB3/EO1]

Sommer, Ulrich ; Hansen, Thomas ; Blum, Olga ; Holzner, Nina ; Vadstein, Olav ; Stibor, Herwig:
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 .
In: Oecologia 142 (2005), S. 274-283
Stichwörter:  [FB3/EO1]; [FB3/EOE-N]; Nutrient ratios; Trophic level; Grazing; Microzooplankton; Mesozooplankton

Sommer, Frank ; Saage, Andrea ; Santer, Barbara ; Hansen, Thomas ; Sommer, Ulrich:
Linking foraging strategies of marine calanoid copepods to patterns of nitrogen stable isotope signatures in a mesocosm study .
In: Marine Ecology Progress Series 286 (2005), S. 99-106
Stichwörter:  [FB3/EO1]; [FB3/EOE-N]; Nitrogen stable isotopes; Trophic enrichment; Food webs; Foraging strategy; Copepods; Mesocosm; Zooplankton
[doi>10.3354/meps286099]

Stibor, H. ; Vadstein, O. ; Diehl, S. ; Gelzleichter, A. ; Hansen, Thomas ; Hantzsche, F. ; Katechakis, A. ; Lippert, B. ; Loeseth, K. ; Petersen, Christer ; Roederer, W. ; Sandow, Marcel ; Sundt-Hansen, L. ; Olsen, Y. :
Copepods act as switch between alternative trophic cascades in marine pelagic food webs .
In: Ecology letters 7 (2004), S. 321-328
Stichwörter:  [FB3/EO1]

Katechakis, A. ; Stibor, H. ; Sommer, Ulrich ; Hansen, Thomas:
Feeding selectivities and food niche separation of Acartia clausi, Penilia avirostris (Crustacea) and Doliolum denticulatum (Thaliacea) in Blanes Bay (Catalan Sea, NW Mediterranean) .
In: Journal of Plankton Research 26 (2004), S. 589-603
Stichwörter:  [FB3/EOE-N]

Sommer, Ulrich ; Hansen, Thomas ; Stibor, H. ; Vadstein, O.:
Persistence of phytoplankton responses to different Si:N ratios under mesozooplankton grazing pressure: a mesocosm study with Northeast Atlantic plankton .
In: Marine Ecology Progress Series 278 (2004), S. 67-75
Stichwörter:  [FB3/EO1]; [FB3/EOE-N]

Sommer, Ulrich ; Sommer, Frank ; Feuchtmayr, H. ; Hansen, Thomas:
The influence of mesozooplankton on phytoplankton nutrient limitation: A mesocosm study with northeast Atlantic phytoplankton .
In: Protist 155 (2004), S. 295-304
Stichwörter:  [FB3/EO1]; [FB3/EOE-N]

Sommer, F. ; Santer, B. ; Jamieson, C. ; Hansen, Thomas ; Sommer, Ulrich:
Daphnia population growth but not moulting is a substantial phosphorus drain for phytoplankton .
In: Freshwater Biol. (2003), Nr. 48, S. 67-74
Stichwörter:  [FB3/EO1]

Sommer, F. ; Hansen, Thomas ; Feuchtmayr, H. ; Santer, B. ; Tokle, N. ; Sommer, Ulrich:
Do calanoid copepods supress appendicularians in the coastal ocean?
In: J. Plankton. Res. (2003), Nr. 25, S. 869-871
Stichwörter:  [FB3/EO1]

Katechakis, A. ; Stibor, H. ; Sommer, Ulrich ; Hansen, Thomas:
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) .
In: Mar. Ecol. Progr. Ser. (2002), Nr. 234, S. 55-69
Stichwörter:  [FB3/EO1]

Sommer, Ulrich ; Berninger, U.G. ; Böttger-Schnack, R. ; Hansen, Thomas ; Stibor, H. ; Schnack-Schiel, S.B. ; Cornils, A. ; Hagen, W. ; Wickham, S. ; Al-Najjar, T. ; Post, A.F.:
Grazing during the spring bloom in the Gulf of Aquaba and the Northern Red Sea .
In: Mar. Ecol. Progr. Ser. (2002), Nr. 239, S. 251-261
Stichwörter:  [FB3/EO1]

Sommer, Ulrich ; Stibor, H. ; Katechakis, A. ; Sommer, Frank ; Hansen, Thomas:
Pelagic food web configurations at different levels of nutrient richness and their implications for the ratio fish production: primary production .
In: Hydrobiologia (2002), Nr. 484, S. 11-20
Stichwörter:  [FB3/EO1]