TLDR: YES. Are they rare? YES. Are they dangerous? NOT really.
According to the Global Shark Attack File (GSAF), a spreadsheet of human/shark interactions, compiled by the Shark Research Institute over the last 130 years, there have only been 14 attacks leading to death in Croatia (and the last one was 46 years ago).
Source: http://www.sharkattackdata.com/place/croatia
Shark sightings in Croatian waters are really rare. There is no tourist industry around them for diving/cage diving/fishing. During our fishing trips (+300 in recent 3 years) it happened only once that we caught Blue Shark (around 15 kg/33 lbs) and we successfully released it – video following:
Blue Shark catch&release in Dubrovnik
The Adriatic Sea is considered extremely safe for swimming. There are about 20–30 species of sharks, but only two species of sharks that can rarely be seen in the Adriatic sea are dangerous to humans: the great white shark and the shortfin mako shark.
For those who want to read more about real dangers on Croatia’s coast we suggest you check this article by Sven Milekic, BalkanInsight. Warning: good humour included.
Sharks Aren’t the Real Killers On Croatia’s Coast
Cover photo: The Wandering Lens