Assessing behaviour of fish in their natural environment is technically challenging and often knowledge on behaviours such as feeding, spawning, migration, and predator-prey interactions are inferred from fishing surveys or by observations in simplified laboratory experiments.
However, these approaches can provide very little information on how behaviours of individuals, which are related to habitat choice, foraging tactics, intra- and interspecific interactions, vary on seasonal, circadian and shorter timescales. Despite studies dating back more than a century ago, these behavioural aspects of the ecology of salmonids in Thingvallavatn are still poorly understood.
