In rivers with hydropower development, river connectivity is degraded or, in many cases, completely disrupted, resulting in bottlenecks for the life-history completion of riverine fish populations in general and of diadromous fish populations in particular. To resolve such anthropogenically induced bottlenecks, fish passage solutions are typically implemented at migration barriers. Evaluation often shows that passage solutions perform poorly. Even more alarmingly, the vast majority of the implemented passage solutions remain unevaluated and their functionality is hence unknown.
Calles has led several research projects on fish migration and the design, implementation and evaluation of fish passage solutions funded by e.g. Formas, the KK-foundation, Energiforsk etc. More recent examples are the newly initiated Horizon 2020 - Marie Skłodowska-Curie Innovative Training Network RIBES (https://www.msca-ribes.eu/) and the EU-LIFE Nature and Biodiversity project LIFE Connects (https://lifeconnects.se/?lang=en).
Calles is part of the River Ecology and management research group (RivEM) (https://www.kau.se/en/nrrv) that was awarded extra internal funding to develop from a strong to an excellent research group.
I have been teaching throughout my academic career, and I have been involved in courses such as Basic Ecology, Freshwater Ecology, Ecological Resource Management, Evolution and I am currently course leader of the Master course Methods in Freshwater Ecology. I find teaching and course development very rewarding and take great joy in contributing to the successful education of our students. This has been achieved by teaching theory, concepts and practical biology at the undergraduate level, as well as course development and supervising bachelor and master theses and engaging students in ongoing research projects. To increase the contact between students and potential employers, one of my main activities as subject representative (ämnesföreträdare) in 2019 was to initiate “Grön dag” (Green day). Grön dag 2019 included a full-day program with workshops and presentations by potential employers, researchers and students.
Externally funded applied research projects is all about external cooperation of which I now have close to 20 years’ of experience. I have collaborated with a large variety of external partners such as County Administration Boards (e.g. Gävleborg, Kalmar, Blekinge, Uppsala, Skåne, Halland), municipalities (e.g. Gävle, Falkenberg, Mönsterås, Karlstad etc.), major power companies (e.g. Uniper, Vattenfall, Fortum, Statkraft, Tekniska verken etc.), privately owned power companies (Vebro industri AB, Ulf Levein, Knut Aal AS etc.), consultancies (e.g. Sweco, Norconsult, Fiskevårdsteknik AB, Hydroterra) and international companies and organizations like Latvenergo (Latvia), World fish migration foundation (Netherlands), WWF (Netherlands), ICE (Costa Rica) and Food and Agriculture Organization of the United Nations (Italy).
- Harbicht, A.B., Watz, J., Nyqvist, D., Virmaja, T., Carlsson, N., Aldvén, D., Nilsson, P.A. and Calles, O. (2022). An experimental assessment of the efficiency of angled and inclined fish guidance screens with varying gap widths for downstream migrating salmon smolts. Ecological Engineering. 174(2): 106438.
- Calles, O., Elghagen, J., Nyqvist, D., Harbicht, A.B., and Nilsson, P.A. (2021). Efficient and timely downstream passage solutions for European silver eels at hydropower dams. Ecological Engineering. 170: 106350.
- Szabo-Meszarosa, M., Silva, A.T., Baerum, K.H., Baktoft, H., Alfredsen, K., Hedger, R.D., Okland, F., Gjelland, K.O., Fjeldstad, H-P., Calles, O. and Forseth, T. (2021). Validation of a Swimming Direction Model for the downstream migration of Atlantic salmon smolts. Water. 13, 1230.
- Lund Björnås, K., Railsback, S.F., Calles, O. and Piccolo, J.J. (2021). Modeling Atlantic salmon (Salmo salar) and brown trout (S. trutta) population responses and interactions under increased minimum flow in a regulated river. Ecological Engineering. 16: 106182.
- Harbicht, A.B., Nilsson, P.A., Österling, M. and Calles, O. (2021). Environmental and anthropogenic correlates of migratory speeds among Atlantic salmon smolts. River Research & Applications. 37: 358-372.
- Vikström, L, Leonardsson, K., Calles, O., Leander, J., Shry, S. and Hellström, G. 2020. Validation of Francis and Kaplan Turbine Blade Strike Models for Adult and Juvenile Atlantic Salmon and Anadromous Brown Trout Passing High Head Turbines. Sustainability. 12(16): 1-13.
- Watz, J., Aldvén, D., Apostolos Brouziotis, A., Carlsson, N., Karathanou, E., Lund-Bjørnås, K., Lundqvist, G., Österling, M., Piccolo, J.J. and Calles, O. (2020). Social behaviour of European grayling before and after flow peaks in restored and unrestored habitats. River Research & Applications. 36: 1646–1655.