Archiv Detail

Otto-Jaag-Preis für 2025 doppelt verliehen

13. März 2026 | Andri Bryner

Isotopenmarker zum Aufschlüsseln von Nahrungsnetzen und deren Veränderung nutzen sowie Wege und Anreicherung von Schadstoffen in Wasserorganismen verfolgen – gleich für zwei spannende und thematisch sehr aktuelle Doktorarbeiten wurde 2025 der Otto-Jaag-Gewässerschutzpreis verliehen.

Dank einer Aufstockung des Otto-Jaag-Gewässerschutzpreises durch die ehemalige Eawag Direktorin, Janet Hering, konnten 2025 gleich zwei Preise für hervorragende Doktorarbeiten ausgerichtet werden. Sie gingen an den Umweltchemiker Johannes Raths und den Evolutionsbiologen Grégoire Saboret.

Nahrungskette dank Isotopenanalyse rekonstruiert

Grégoire Saboret hat an der Eawag in Kastanienbaum geforscht unter der Leitung von Prof. Dr. Carsten Schubert (Abteilung Oberflächengewässer). Unter der Mitbetreuung durch Dr. Jakob Brodersen und Dr. Blake Matthews (Abteilung Fischökologie und Evolution) hat er Isotopenanalysen von Aminosäuren weiterentwickelt und namentlich an Fischen angewendet. So konnte er das Verständnis für Nahrungsnetze erweitern, denn die Marker geben Aufschluss über Primärproduzenten (Algen und Bakterien) und alle Zwischenkonsumenten, von denen sie sich ernährt haben. So hat Saboret unter anderem aufgezeigt, wie die Eutrophierung von Seen die Produktionsquellen in den Nahrungsnetzen der Schweizer Seen beeinflusst oder wie aktuell das Abschmelzen der Gletscher in Grönland die Ernährung der Fische verändert.

Fischaugen mit Jahrringen

Grégoire Saboret hat ein Mobilitätsstipendium des Nationalfonds bekommen und weilt aktuell an der University of California in Santa Cruz. Er forscht und publiziert aber weiterhin auch zusammen mit Eawag Kolleginnen und Kollegen. Zurzeit ist eine Publikation in Vorbereitung, die Kohlenstoff- und Stickstoffisotope aus den Linsen von Fischaugen analysiert. Da die Linsen ringförmig wachsen, bilden diese Ringe, ähnlich wie Jahrringe bei einem Baum, ein Archiv, welches Aufschluss über den ganzen Lebenszyklus des Fischs gibt.

Wie Gewässerorganismen Schadstoffe aufnehmen

Johannes Raths forschte für seine Dissertation in der Abteilung Umweltchemie, betreut von Dr. Juliane Hollender. Die Arbeit hat toxikokinetische Prozesse in Wasserorganismen untersucht, also zum Beispiel, wie Pestizide und Arzneimittel aufgenommen werden, sich anreichern, sich im Organismus verändern und allenfalls auch wieder ausgeschieden werden. Diese Mechanismen sind eine Brücke zwischen der Verschmutzung von Gewässern auf der einen und deren Wirkung auf aquatische Lebensgemeinschaften und Ökosysteme auf der anderen Seite. «Ein wirksamer Schutz von Gewässern ist eigentlich nur möglich, wenn wir diese Prozesse und ihre Veränderung im globalen Wandel der Umwelt verstehen», sagt Betreuerin, Prof. Dr. Juliane Hollender. Sie ist überzeugt, Raths interdisziplinäre Forschung werde sowohl in Lehrbüchern als auch in der Praxis Niederschlag finden.

Beide ausgezeichneten Forscher konnten leider an der Verleihung, anlässlich des ETH-Tages im vergangenen November nicht teilnehmen. Auf Anfrage sagen sowohl Raths als auch Saboret, sie würden die Auszeichnung als grosse Ehre empfinden und heben die erlebte Unterstützung an der Eawag hervor. Saboret betont, der Preis sei auch eine Anerkennung für eine Arbeit, die den Schutz aquatischer Ökosysteme würdige. Raths stellt derweil das Zusammenspiel von Klimawandel und Umweltverschmutzung in seinen Arbeiten in den Vordergrund: Dieses werde uns in Zukunft noch intensiv beschäftigen.
 

Neue Kandidatinnen und Kandidaten gesucht

Der Otto-Jaag-Gewässerschutzpreis prämiert die beste Dissertation, in speziellen Fällen auch die beste Masterarbeit, an der ETH Zürich auf dem Gebiet des Gewässerschutzes und der Gewässerkunde. Vorschlagberechtigt für den Preis sind Mitglieder des Lehrkörpers der ETH Zürich. Das Preisgeld beträgt 5'000 Franken. Eingaben für den Preis 2026 können bis zum 1. Juni gemacht werden.

Dissertationen

Extbase Variable Dump
array(3 items)
   publications => '36402,36404' (11 chars)
   libraryUrl => '' (0 chars)
   layout => '0' (1 chars)
Extbase Variable Dump
array(2 items)
   0 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=36402, pid=124)
      originalId => protected36402 (integer)
      authors => protected'Raths, J.' (14 chars)
      title => protected'Bioaccumulation of polar organic contaminants in aquatic invertebrates: impa
         ct of climate, uptake pathways and spatial distribution
' (131 chars) journal => protected'' (0 chars) year => protected2023 (integer) volume => protected0 (integer) issue => protected'' (0 chars) startpage => protected'288 p' (10 chars) otherpage => protected'' (0 chars) categories => protected'' (0 chars) description => protected'Global freshwater resources are threatened by a range of human activities in
         cluding pollution and accelerating global climate change. Environmental cont
         aminants are numerous and can form complex contamination patterns and mixtur
         es in aquatic systems. The vast majority of organic contaminants originates
         from human use and enters aquatic environments from agricultural, industrial
          and household emissions. Pharmaceuticals and pesticides are contaminants of
          particular concern as they are specifically designed to be biologically act
         ive and thus cause adverse effects on non-target organisms such as aquatic i
         nvertebrates. Aquatic invertebrates, including amphipods, provide important
         ecological functions such as detritus processing and transfer of energy to h
         igher trophic levels that maintain the functionality and diversity of aquati
         c ecosystems. [...]
' (855 chars) serialnumber => protected'' (0 chars) doi => protected'10.3929/ethz-b-000641995' (24 chars) uid => protected36402 (integer) _localizedUid => protected36402 (integer)modified _languageUid => protectedNULL _versionedUid => protected36402 (integer)modified pid => protected124 (integer)
1 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=36404, pid=124) originalId => protected36404 (integer) authors => protected'Saboret, G.' (16 chars) title => protected'Trophic dynamics in meta-ecosystems: insights from compound-specific stable
         isotopes
' (84 chars) journal => protected'' (0 chars) year => protected2024 (integer) volume => protected0 (integer) issue => protected'' (0 chars) startpage => protected'197 p' (10 chars) otherpage => protected'' (0 chars) categories => protected'' (0 chars) description => protected'Food webs are crucial for understanding how carbon and nutrients flow within
          ecosystems, influencing sustainability and carbon fluxes. Ecosystems are in
         terconnected, exchanging energy, nutrients, and organic matter—a concept c
         aptured by meta-ecosystem theory. Consequently, changes in one ecosystem can
          have cascading effects on others. This interconnectedness becomes increasin
         gly important as global change drives significant alterations in food webs.
         Therefore, there is a pressing need to characterize food web functioning in
         complex settings, such as meta-ecosystems, and to study how these webs are i
         mpacted by global change. [...]
' (639 chars) serialnumber => protected'' (0 chars) doi => protected'10.3929/ethz-b-000699978' (24 chars) uid => protected36404 (integer) _localizedUid => protected36404 (integer)modified _languageUid => protectedNULL _versionedUid => protected36404 (integer)modified pid => protected124 (integer)
Raths, J. (2023) Bioaccumulation of polar organic contaminants in aquatic invertebrates: impact of climate, uptake pathways and spatial distribution, 288 p, doi:10.3929/ethz-b-000641995, Institutional Repository
Saboret, G. (2024) Trophic dynamics in meta-ecosystems: insights from compound-specific stable isotopes, 197 p, doi:10.3929/ethz-b-000699978, Institutional Repository

Weitere Originalpaper

Extbase Variable Dump
array(3 items)
   publications => '33871,33076,36402,31058' (23 chars)
   libraryUrl => '' (0 chars)
   layout => '0' (1 chars)
Extbase Variable Dump
array(4 items)
   0 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=33871, pid=124)
      originalId => protected33871 (integer)
      authors => protected'Saboret, G.; Moccetti, C.; Wassenaar, L. I.; Matthews,&n
         bsp;B.; Aquino, N. J.; Janssen, D. J.; Brodersen, J
         .; Schubert, C. J.
' (180 chars) title => protected'Impact of glaciers on trophic dynamics and polyunsaturated fat accumulation
         in Southern Greenland Fjord ecosystems
' (114 chars) journal => protected'Global Change Biology' (21 chars) year => protected2025 (integer) volume => protected31 (integer) issue => protected'1' (1 chars) startpage => protected'e70044 (19 pp.)' (15 chars) otherpage => protected'' (0 chars) categories => protected'amino acid isotope; arctic char; fjord; food web; glacier; Greenland; polyun
         saturated fatty acid; trophic position
' (114 chars) description => protected'The primary production of fjords across the Arctic and Subarctic is undergoi
         ng significant transformations due to the climatically driven retreat of gla
         ciers and ice sheets. However, the implications of these changes for upper t
         rophic levels remain largely unknown. In this study, we employ both bulk and
          compound-specific stable isotope analyses to investigate how shifts at the
         base of fjord food webs impact the carbon and energy sources of consumers. F
         ocusing on two rapidly changing fjords in Southern Greenland, we used the mi
         gratory Arctic char as an indicator species, sampling populations along envi
         ronmental gradients within the fjords, building upon the assumption that cha
         r populations feed primarily close to their natal stream, thereby integratin
         g a dietary gradient. Our analysis of bulk stable isotopes in Arctic char ti
         ssue confirmed this premise, revealing a consistent change in resource use f
         rom the outer to the inner fjord, which nonetheless served as preferred feed
         ing grounds. Essential amino acid analysis further indicated shifts in carbo
         n and nitrogen sources, consistent with changes in nutrient use near glacier
          inputs characterized by low turbidity and high iron levels. Notably, these
         changes in the source of primary production were associated with shifts in t
         rophic positions and the transfer of polyunsaturated fatty acids, with Arcti
         c char in glacier-influenced inner fjords feeding at lower trophic level (si
         ze-corrected) and accumulating higher levels of high-quality docosahexaenoic
          acid (DHA). These findings highlight the usefulness of new analytical tools
          in revealing that glacial retreat can substantially alter food web dynamics
         , enhancing both carbon flow and the nutritional quality of fish in fjord ec
         osystems. The two Southern Greenland fjords studied could represent the futu
         re of other fjords, where retreating glaciers become land-terminating and gl
         acial inputs decrease. Our study underscores the critical role of glacier dy
         namics in affecting high...
' (2075 chars) serialnumber => protected'1354-1013' (9 chars) doi => protected'10.1111/gcb.70044' (17 chars) uid => protected33871 (integer) _localizedUid => protected33871 (integer)modified _languageUid => protectedNULL _versionedUid => protected33871 (integer)modified pid => protected124 (integer)
1 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=33076, pid=124) originalId => protected33076 (integer) authors => protected'Saboret, G.; Drost, B. J. W.; Kowarik, C.; Schubert
         , C. J.; Gossner, M. M.; Ilić, M.
' (135 chars) title => protected'Quantifying the utilisation of blue, green and brown resources by riparian p
         redators: a combined use of amino acid isotopes and fatty acids
' (139 chars) journal => protected'Methods in Ecology and Evolution' (32 chars) year => protected2024 (integer) volume => protected15 (integer) issue => protected'8' (1 chars) startpage => protected'1450' (4 chars) otherpage => protected'1462' (4 chars) categories => protected'amino acids; CSIA; food webs; MixSIAR; nutrient fluxes; polyunsaturated fatt
         y acids; spiders; stable isotopes
' (109 chars) description => protected'1. Global change drives multiple facets of biodiversity including interactio
         n diversity, which is fundamental for ecosystem functioning. However, studyi
         ng trophic interactions is challenging in meta-ecosystems, that is ecosystem
         s connected by spatial flows of energy, materials and organisms across ecosy
         stem boundaries. While analytical methods based on abundances of polyunsatur
         ated fatty acids (PUFAs) and stable isotopes of amino acids (AAs) are being
         increasingly used, it has never been explored if both approaches could be: (
         i) combined in mixing models to enhance precision in dietary inference (ii)
         compared to disentangle transfers of various PUFAs and proteins in food webs
          in the wild.<br />2. We explore the utility of analytical approaches based
         on PUFA abundances and AA isotopes to resolve resource transfers in a natura
         l riparian food web. We focus on spiders and their potential prey from blue,
          green and brown sources to address three important and persisting methodolo
         gical issues in food-web ecology, namely whether (i) essential AA carbon iso
         topes can resolve protein origin from blue, green and brown resources, (ii)
         PUFA relative abundance and AA isotopes can be combined in a mixing model to
          provide higher precision estimates (i.e. narrower intervals) and (iii) comb
         ining the two approaches can unveil the coupling of protein and PUFA transfe
         rs in food webs. 3. Our research demonstrates the power of AA isotopes and P
         UFAs to distinguish blue, green, and brown sources and their transfer up to
         consumers. We show that combining PUFA relative abundance and AA isotopes in
          a mixing model provides overall estimates similar to the individual estimat
         es but significantly increases precision. In addition, we showcase how combi
         ning approaches unveil the coupling of protein and PUFA transfers. For insta
         nce, we show that most PUFAs are less concentrated from prey to predators, r
         elative to proteins, highlighting uncoupling of PUFAs and protein transfer a
         long food chains.<br />4...
' (2301 chars) serialnumber => protected'2041-210X' (9 chars) doi => protected'10.1111/2041-210X.14371' (23 chars) uid => protected33076 (integer) _localizedUid => protected33076 (integer)modified _languageUid => protectedNULL _versionedUid => protected33076 (integer)modified pid => protected124 (integer)
2 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=36402, pid=124) originalId => protected36402 (integer) authors => protected'Raths,&nbsp;J.' (14 chars) title => protected'Bioaccumulation of polar organic contaminants in aquatic invertebrates: impa
         ct of climate, uptake pathways and spatial distribution
' (131 chars) journal => protected'' (0 chars) year => protected2023 (integer) volume => protected0 (integer) issue => protected'' (0 chars) startpage => protected'288&nbsp;p' (10 chars) otherpage => protected'' (0 chars) categories => protected'' (0 chars) description => protected'Global freshwater resources are threatened by a range of human activities in
         cluding pollution and accelerating global climate change. Environmental cont
         aminants are numerous and can form complex contamination patterns and mixtur
         es in aquatic systems. The vast majority of organic contaminants originates
         from human use and enters aquatic environments from agricultural, industrial
          and household emissions. Pharmaceuticals and pesticides are contaminants of
          particular concern as they are specifically designed to be biologically act
         ive and thus cause adverse effects on non-target organisms such as aquatic i
         nvertebrates. Aquatic invertebrates, including amphipods, provide important
         ecological functions such as detritus processing and transfer of energy to h
         igher trophic levels that maintain the functionality and diversity of aquati
         c ecosystems. [...]
' (855 chars) serialnumber => protected'' (0 chars) doi => protected'10.3929/ethz-b-000641995' (24 chars) uid => protected36402 (integer) _localizedUid => protected36402 (integer)modified _languageUid => protectedNULL _versionedUid => protected36402 (integer)modified pid => protected124 (integer)
3 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=31058, pid=124) originalId => protected31058 (integer) authors => protected'Raths,&nbsp;J.; Schinz,&nbsp;L.; Mangold-Döring,&nbsp;A.; Hollender,&nbsp;J
         .
' (77 chars) title => protected'Elimination resistance: characterizing multi-compartment toxicokinetics of t
         he neonicotinoid thiacloprid in the amphipod <em>Gammarus pulex</em> using b
         ioconcentration and receptor-binding assays
' (195 chars) journal => protected'Environmental Science and Technology' (36 chars) year => protected2023 (integer) volume => protected57 (integer) issue => protected'24' (2 chars) startpage => protected'8890' (4 chars) otherpage => protected'8901' (4 chars) categories => protected'bioaccumulation; invertebrates; micropollutants; organic contaminants; insec
         ticides
' (83 chars) description => protected'Delayed toxicity is a phenomenon observed for aquatic invertebrates exposed
         to nicotinic acetylcholine receptor (nAChR) agonists, such as neonicotinoids
         . Furthermore, recent studies have described an incomplete elimination of ne
         onicotinoids by exposed amphipods. However, a mechanistic link between recep
         tor binding and toxicokinetic modeling has not been demonstrated yet. The el
         imination of the neonicotinoid thiacloprid in the freshwater amphipod <em>Ga
         mmarus pulex</em> was studied in several toxicokinetic exposure experiments,
          complemented with in vitro and in vivo receptor-binding assays. Based on th
         e results, a two-compartment model was developed to predict the uptake and e
         limination kinetics of thiacloprid in <em>G. pulex</em>. An incomplete elimi
         nation of thiacloprid, independent of elimination phase duration, exposure c
         oncentrations, and pulses, was observed. Additionally, the receptor-binding
         assays indicated irreversible binding of thiacloprid to the nAChRs. Accordin
         gly, a toxicokinetic-receptor model consisting of a structural and a membran
         e protein (including nAChRs) compartment was developed. The model successful
         ly predicted internal thiacloprid concentrations across various experiments.
          Our results help in understanding the delayed toxic and receptor-mediated e
         ffects toward arthropods caused by neonicotinoids. Furthermore, the results
         suggest that more awareness toward long-term toxic effects of irreversible r
         eceptor binding is needed in a regulatory context. The developed model suppo
         rts the future toxicokinetic assessment of receptor-binding contaminants.
' (1593 chars) serialnumber => protected'0013-936X' (9 chars) doi => protected'10.1021/acs.est.3c01891' (23 chars) uid => protected31058 (integer) _localizedUid => protected31058 (integer)modified _languageUid => protectedNULL _versionedUid => protected31058 (integer)modified pid => protected124 (integer)
Saboret, G.; Moccetti, C.; Wassenaar, L. I.; Matthews, B.; Aquino, N. J.; Janssen, D. J.; Brodersen, J.; Schubert, C. J. (2025) Impact of glaciers on trophic dynamics and polyunsaturated fat accumulation in Southern Greenland Fjord ecosystems, Global Change Biology, 31(1), e70044 (19 pp.), doi:10.1111/gcb.70044, Institutional Repository
Saboret, G.; Drost, B. J. W.; Kowarik, C.; Schubert, C. J.; Gossner, M. M.; Ilić, M. (2024) Quantifying the utilisation of blue, green and brown resources by riparian predators: a combined use of amino acid isotopes and fatty acids, Methods in Ecology and Evolution, 15(8), 1450-1462, doi:10.1111/2041-210X.14371, Institutional Repository
Raths, J. (2023) Bioaccumulation of polar organic contaminants in aquatic invertebrates: impact of climate, uptake pathways and spatial distribution, 288 p, doi:10.3929/ethz-b-000641995, Institutional Repository
Raths, J.; Schinz, L.; Mangold-Döring, A.; Hollender, J. (2023) Elimination resistance: characterizing multi-compartment toxicokinetics of the neonicotinoid thiacloprid in the amphipod Gammarus pulex using bioconcentration and receptor-binding assays, Environmental Science and Technology, 57(24), 8890-8901, doi:10.1021/acs.est.3c01891, Institutional Repository


Titelbild: Das Abschmelzen der Gletscher verändert die Nahrungsnetze in den Gewässern, wie hier in Grönland, aber auch im alpinen Raum. (Foto: Coralie Moccetti)