I remember reading a book about 25 years ago (so around 1990?) which featured shapeshifting killer whales as the antagonists.
- It had a techno-fantasy feel to it, with people having body-phones tattooed on their skin
- (plot point: one of the protagonists had lost his phone when he suffered a skin injury)
- The Orcas could take human form
- I think it was a series with multiple books, pretty sure I only read the second one
- It was in my primary school (elementary school) library
- The protagonists were surfers maybe? I think it was set either in Queensland Australia, or California.
- Might have had a conservationalist/Eco-warrior theme; "save the environment before it destroys us" kind of thing.