Tiu Similä started to study killer whales in northern Norway in 1986.
The long-term project she was in charge of resulted in Tius own PhD on behavioral ecology of killer whales in 1997, two other PhD thesis, four MSc and three BSc thesis in addition to several collaborations with scientists around the world. Tius main interest is the interactions between Norwegian killer whales and their main type of prey – the Norwegian spring spawning herring; hunting techniques and other behavior, seasonal distribution and habitat use of killer whales are all linked to behavior of herring.
In 2006 Tiu handed over the long-term study to others, but is still closely involved in killer whale research. Tiu was involved in establishing the first whale watch operation in Norway, Whalesafari in Andenes, and worked with developing killer whale watching in Tysfjord. Tiu has worked together with the company Lofoten Opplevelser since 1995