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The Ä¢¹½Ö±²¥ together with the Natural Resources Institute Finland (Luke), is organising the National Fish Research Days on 1-2 April 2025 at the Agora building on the Mattilanniemi campus. For the fifth time, the Fish Research Days will focus widely on fish biology and sustainable use of fish resources. The Fish Research Days will cover topics such as the development of fisheries in Lake Pyhäjärvi in Säkylä in a changing climate, and the effects of seasonality on the structure of the fish stocks in Lake Pääjärvi.

A scientific approach to decision-making

The exploitation of living natural resources, especially natural populations, requires socio-economic discussion and decision-making. Interdisciplinary fisheries research responds to this need and provides information for decision making. 

- The Fish Research Days will focus on how to estimate the size of the spawning stock of vendace, how the seasonal timing of the pike fishery affects total catches and how the growth rate of zander has changed in the Archipelago Sea. The Days will also cover the controversies surrounding the acquisition of fishing permits and the factors that affect them, explains Doctoral Researcher Tuula Väänänen from the Ä¢¹½Ö±²¥.

Fish well-being is a key factor in sustainable fish farming

The days will include practical experiences of fish habitat restoration and downstream migration structures in the Mustionjoki River.  

- The section on farmed fish well-being studies will include how light and feeding cycles affect the well-being, how rearing in enriched condition influences the properties of the salmon fry, says Väänänen. 

In the session of environmental risk assessment, a topic is the sulfate sensitivity of organisms in the Baltic Sea. Researchers will also explain what the Baltic Sea lamprey is doing.

- The latest information will also be provided on the spread of crayfish plague and how population density affects the migration susceptibility of trout, tells Väänänen.  

The role of seabirds in fish farming and coastal fisheries 

There will be new research results and a discussion about seabirds and fisheries. Presentations will include information on the predation of cormorants and grey herons in fish farms and on bycatch of seabirds in coastal fisheries.

Presentations and posters provide a wide range of information from fish research

Altogether 139 participants have registered for the live seminar and 121 for the webinar. There will be 20 oral presentations and 11 posters in the poster exhibition. All presentations are in Finnish.

- The poster exhibition will explain how to estimate sustainable fishing effort for pike and perch and how to automatically calculate the number of fish in traps in coastal fisheries. The exhibition will also include information on the co-farming of fish and other species and the use of mussels in the biofiltering of water mold, says Väänänen.

The programme of the Fish Research Days can be found at: /fi/tapahtumat/kansalliset-kalatutkimuspaivat-2025 

Further information:

• Doctoral Researcher Tuula Väänänen: tuula.m.vaananen@jyu.fi
• Lecturer Timo J. Marjomäki: timo.j.marjomaki@jyu.fi
• Professori Juha Karjalainen: juha.s.karjalainen@jyu.fi
• Timo Ruokonen: timo.ruokonen@luke.fi
• Tapio Keskinen: tapio.keskinen@luke.fi