Lana Pađen, Maja Maurić: The mortality of cetacea (Cetacea) in Croatian part of the Adriatic Sea. Original scientific
student paper. Faculty of
Abstract
The objectives of this
study were to determine cetacean species
present in the Adriatic Sea, their abundance, distribution, the period of the
year (months) in which the mortality is the highest, and the sex and age of the
found carcasses. We analyzed data of whales found dead in the Croatian part of
the Adriatic Sea from October 1990 till December 2007. In this period in the
Croatian part of the Adriatic Sea 151 dead whales were found in total (120
bottlenose dolphins (Tursiops truncatus),
17 striped dolphins (Stenella coeruleoalba),
9 Risso's dolphins (Grampus griseus), 3 Cuvier´s
beaked whales (Ziphius cavirostris)
and 2 fin whales (Balaenoptera physalus).
This study confirmed that the only residential habitant of the Adriatic Sea is
the bottlenose dolphin. The most frequent non residential whale is the striped
dolphin. Some non residential specimen was found in the parts of the Adriatic
where the depths are lower than the usual depths of their biotope. Mostly adult
striped dolphins die in the Adriatic Sea while in the fin whales only juvenile
specimens were found. The mortality of males and females is almost equal in the
bottlenose and striped dolphins, while males prevale
in the Risso's dolphins. Most findings of the dead
bottlenose dolphins were in April and from July till November, while non
residential species were found equally during all months in the year except
August, September and October. Given results amplify the cognition about
biology of the whales and can help the possibility of their protection.