My research lies within the field of zooplankton and larval fish taxonomy and ecology. The study of key environmental factors governing mesozooplankton and fish larvae community structure has been one of my major research lines. My expertise in taxonomy and biological-physical coupling were initially developed through my research in the Mediterranean ecosystems using traditional taxonomic criteria. From 2015-2018, my research was extended to the Red Sea environment and incorporated the application of molecular techniques for species identification and biodiversity assessment.
I have additionally developed a parallel multi-year engagement in zooplankton eco-physiological studies, aiming to better understand the organismal responses to environmental parameters/stressors, the “bottom up” processes and overall trophic interactions in the planktonic food web. I have explored interactions between different trophic levels (phytoplankton, microzooplankton, mesozooplankton) aiming to gain a broad and in-depth understanding of the structure and function of marine planktonic environments.
In IMR, I am leading the Plankton Research (Theme 6: "Plankton Dynamics") in the the EAF-Nansen Programme (https://www.fao.org/in-action/eaf-nansen/en/)
RESEARCH INTERESTS
EDUCATION
2004-2008: PhD in Biology, University of Patras, Greece (Thesis: Mesozooplankton and ichthyoplankton spatiotemporal distribution patterns in the N.E. Aegean Sea in relation to abiotic and biotic variables)
2000-2002: MSc in Environmental Biology and Management of Aquatic and Terrestrial Environments, University of Patras, Greece (Thesis: Mesozooplankton study in Ionian Sea and coastal waters of central Greece – Development of a digital identification key for mesozooplankton)
1996-2000: BSc in Biology, University of Patras, Greece (Thesis: Study of the zooplankton community of Koutavos lagoon and comparison with other lagoon ecosystems of western Greece)
POSITIONS
2018 – present: Senior Research Scientist (Forsker 1183), Plakton Group, IMR Bergen
2015 – 2018: Research Scientist, Red Sea Research Center (RSRC-KAUST), Kingdom of Saudi Arabia
2014 – 2015: Post-doctoral researcher, Hellenic Centre for Marine (HCMR), Institute of Oceanography, Athens, Greece
2009 – 2014: Post-doctoral researcher, Institute of Marine Sciences-CSIC (ICM-CSIC), Department of Marine Biology & Oceanography, Barcelona, Spain
2008 – 2009: Post-doctoral researcher, HCMR, Institute of Marine Biological Resources, Crete, Greece
PUBLICATION LIST
Saiz E., Griffell K., Isari S., Calbet A. (2023) Ecophysiological response of marine copepods to dietary elemental imbalances. Mar. Env. Res., Vol. 186, 1–10, DOI: https://doi.org/10.1016/j.marenvres.2023.10594
Tiedemann M., Ndour I., Ngom Sow F., Bagøien E., Krakstad J. O., Ostrowski M., Stenevik E. K., Ensrud T., Isari S. (2022) Asynchronized spawning responses of small pelagic fishes to a short term environmental change. Mar. Ecol. Prog. Ser., Vol. 696, 85–102, DOI: https://doi.org/10.3354/meps14122
Isari S., Pearman J.K., Casas L., Michell C.T., Curdia J., Berumen M.L., Irigoien X. (2017) Exploring the larval fish community of the central Red Sea with an integrated morphological and molecular approach. PLoS ONE 12(8): e0182503.
Alcaraz M., Calbet A., Isari S., Iriogien X., Trepat I., Saiz E. (2016) Variability of mesozooplankton biomass and individual size in a coast-offshore transect in the Catalan Sea: relationships with chlorophyll a and hydrographic features. Sci. Mar. 80S1: 79–87
Atienza D., Sabates A., Isari S., Saiz E., Calbet A. (2016) Environmental limits in the distribution of marine cladocerans in the NW Mediterranean: implications for global warming. J. Mar. Sys. 164: 30–41
Ptacnik R., Gomes A., Royer S.J., Berger S.A. , Calbet A., Nejstgaard J.C., Gasol J.M., Isari S., Moorthi S.D., Ptacnikova R., Striebel M, Sazhin A.F., Tsagaraki T.M., Zervoudaki S., Altoja K., Dimitriou P., Laas P., Gazihan Akoglu A., Martínez R.A., Schabhüttl S., Santi I., Sousoni D., Pitta P. (2016) A light-induced shortcut in the planktonic microbial food web. Sci. Rep. 6: 29286
Isari S., Zervoudaki S., Peters J., Papantoniou G., Pelejero C., Saiz E. (2016) Lack of evidence for elevated CO2-induced bottom-up effects on marine copepods: A dinoflagellate-calanoid prey-predator pair. ICES J Mar. Sci. 73(3): 650–658
Saiz E., Calbet A., Griffell K., Bersano J.G.F., Isari S., Solé M., Peters J., Alcaraz M. (2015) Ageing and caloric restriction in a marine planktonic copepod. Sci. Rep. 5: 14962
Isari S., Zervoudaki S., Saiz E., Pelejero C., Peters J. (2015) Copepod vital rates under CO2-induced acidification: a calanoid species and a cyclopoid species under short term exposures. J. Plankton Res. 37(5): 912–922
Saiz E., Griffell K., Calbet A., Isari S. (2014) Feeding rates and prey/predator size ratios of the nauplii and adult females of the marine cyclopoid copepod Oithona davisae. Limnol. Oceanogr. 59(6): 2077-2088
Isari S., Zervoudaki S., Calbet A., Saiz E., Ptacnikova R., Nejstgaard J.C., Sousoni D., Berger S.A., Ptacnik R. (2014) Light-induced changes on the feeding behaviour of the calanoid copepod Clausocalanus furcatus (Brady, 1883): evidence from a mesocosm study. J. Plankton Res. 36(5): 1233-1246
Heuschele J., Ceballos S., Andersen Borg C.M., Bjaerke O., Isari S., Lasley-Rasher R., Lindehoff E., Souissi A., Souissi S., Titelman J. (2014) Non-consumptive effects of predator presence on copepod reproduction: insights from a mesocosm experiment. Mar. Biol. 161:1653–1666
Martinez R.A., Isari S., Calbet A. (2014) Use of live, fluorescently-labelled algae for measuring microzooplankton grazing in natural communities. J. Exp. Mar. Biol. Ecol. 457: 59–70
Calbet A., Sazhin A.F., Nejstgaard J.C., Berger S.A. , Tait Z.S., Olmos L., Sousoni D., Isari S., Martínez R.A., Bouquet J.M., Thompson E.M., Båmstedt U., Jakobsen H.H. (2014) Future climate scenarios for a coastal productive planktonic food web resulting in microplankton phenology changes and decreased trophic transfer efficiency. PLoS ONE 9(4): e94388
Nikolioudakis N., Isari S., Somarakis S. (2014) Trophodynamics of anchovy in a non-upwelling system: Direct comparison with sardine. Mar. Ecol. Progr. Ser. 500: 215–229
Isari S., Antó M., Saiz E. (2013) Copepod foraging on the basis of food nutritional quality: Can copepods really choose? PLoS ONE 8 (12): e84742
Calbet A., Isari S., Martínez R.A., Saiz E., Garrido S., Peters J., Borrat R.M., Alcaraz M. (2013) Adaptations to feast and famine in different strains of the marine heterotrophic dinoflagellates Gyrodinium dominans and Oxyrrhis marina. Mar. Ecol. Progr. Ser. 483: 67–84
Saiz E., Calbet A., Isari S., Antó M., Velasco E.M., Almeda R., Movilla J., Alcaraz M. (2013) Zooplankton distribution and feeding in the Arctic Ocean during a Phaeocystis pouchetii bloom. Deep-Sea Res. Pt I 72: 17–33
Calbet A., Martínez R.A., Isari S., Zervoudaki S., Nejstgaard J.C., Pitta P., Sazhin A.E, Sousoni S., Gomes A., Berger S.A., Tsagaraki T.M., Ptacnik R. (2012) Effects of light availability on mixotrophy and microzooplankton grazing in an oligotrophic plankton food web: evidences from a mesocosm study in Eastern Mediterranean waters. J. Exp. Mar. Biol. Ecol. 424–425: 66–77
Nikolioudakis N., Isari S., Pitta P., Somarakis S. (2012) Diet of sardine Sardine pilchardus: An “end to end” field study. Mar. Ecol. Progr. Ser. 453: 173–188
Somarakis S., Isari S., Machias A. (2011) Larval fish assemblages in coastal waters of central Greece: reflections of topographic and oceanographic heterogeneity. Sci. Mar. 75(3): 605-618
Isari S., Saiz E. (2011) Feeding performance of the copepod Clausocalanus lividus (Frost and Fleminger 1968). J. Plankton Res. 33(5): 715–728
Isari S., Somarakis S., Christou E.D., Fragopoulu N. (2011) Summer mesozooplankton assemblages in the northeastern Aegean Sea: The influence of Black Sea water and an associated anticyclonic eddy (the Samothraki gyre). J. Mar. Biol. Assoc. U.K 91 (1): 51–63
Isari S., Fragopoulu N., Somarakis S. (2008) Interannual variability in horizontal patterns of larval fish assemblages in the northeastern Aegean Sea (Eastern Mediterranean) during early summer. Est. Coast. Shelf Sci. 79(4): 607–619
Isari S., Psarra S., Pitta P., Mara P., Tomprou M.O., Ramfos A., Somarakis S. Tselepides A., Koutsikopoulos C., Fragopoulu N. (2007) Differential patterns of mesozooplankters’ distribution in relation to physical and biological variables of the Northeastern Aegean Sea (eastern Mediterranean). Mar. Biol.151: 1035–1050
Isari S., Ramfos A., Somarakis S., Koutsikopoulos C., Kallianiotis A., Fragopoulu N. (2006) Mesozooplankton distribution in relation to hydrology of the Northeastern Aegean Sea (Eastern Mediterranean). J. Plankton Res. 28(3): 241–255
Ramfos A., Isari S., Somarakis S., Georgopoulos D., Koutsikopoulos C., Fragopoulu N. (2006) Mesozooplankton community structure in offshore and coastal waters of the Ionian Sea (eastern Mediterranean) during mixed and stratified conditions. Mar. Biol. 150: 29–44