During the last ten years, the speleological objects in the land (island) part of the Kornati National Park attracted the attention of biologists. Caves and holes, as some of typical karst phenomena, are important for the biodiversity of this area.

Among other particularities, they can potentially contain a number of faunistic rarities (e.g. endemic species) in their eco-systems. However, more systematic biospeleological studies of the water fauna in the anchialine caves and holes in the Park are needed because the previous studies have shown very interesting animal finds both in the brackish layer and in the sea water of deeper parts in the holes studied. Endemic freshwater amphipods Niphargus pectencoronatae and Niphargus hebereri were confirmed.

jamaLet's explain some terms:
Holes are subterranean channels with the average gradient between 45° and 90°, deeper than 5 metres.
Caves are subterranean cavities with the channel gradient smaller than 45° and length greater than 5 metres.
Anchialine holes and caves are those holes and caves with subterranean lakes where the salinity (saltiness of the water) varies from the almost fresh water on the surface of the lake to the completely salty water at the bottom. Such caves and holes are limited in their exposure to the external climate influences and always has more or less broad subterranean connection to the sea.

All the studied objects are natural karst holes. They are small speleological objects with water where, said simply, the fresh water is at the surface and salt water at the bottom. One of the holes, 35 metres deep (to the surface of the water) is the deepest known speleological object in the Kornati National Park. All the objects were explored to the surface of the water and the underwater activity was limited to sampling. Because of the great depth, additional speleological diving exploration is needed. That means, because of safety, additional equipment and people. You have to understand that it's not easy, diving in such tight and narrow underground spaces where every mistake can be paid dearly.
Subterranean water animals were found in ten locales while at greater depths, where there's only sea water present, water fauna specimens were collected with a plankton net.
Of course, what was found were not monsters or dragons but very small animals. Nevertheless, they are of a great interest for science.