Journal of the Marine Biological Association of the United Kingdom




CONSERVATION

Bottlenose dolphin (Tursiops truncatus) presence and incidental capture in a marine fish farm on the north-eastern coast of Sardinia (Italy)


Bruno  Díaz López a1c1 and Julia Andrea   Bernal Shirai a1
a1 The Bottlenose Dolphin Research Institute (BDRI), V.A. Díaz No.4 Golfo Aranci, 07020 Sassari, Italy

Article author query
díaz lópez b   [PubMed][Google Scholar] 
bernal shirai ja   [PubMed][Google Scholar] 

Abstract

On the north-eastern coast of Sardinia, from November 2004 to January 2006, the first attempt in the Mediterranean basin to obtain information on encounter rate, group size and incidental capture of bottlenose dolphins in a marine fish farm was assessed, combining direct observations from fish farm boats with photo-identification studies. During 15 months of research, 79 d (65.3% of the total monitored days) were spent in direct observation of 146 groups of bottlenose dolphins around the fish farm cages. There was a peak in bottlenose dolphin presence during winter. Photographs were taken in the fish farm area during 79 encounters on 61 different days (totalling 34 marked individuals). The regular occurrence of some dolphins suggests individual preferences for the fish farm area. The incidental bottlenose dolphin capture observed in large, loose predator nets (1 dolphin per month) is cause for concern, as it is questionable whether or not the bottlenose dolphins in the area can sustain incidental capture of this magnitude. The information gained from this study shows the necessity for further regulations to be established, both in the use of predator nets and management of marine fish farms.

(Published Online February 26 2007)
(Received May 2 2006)
(Accepted September 13 2006)


Correspondence:
c1 Corresponding author, e-mail: bruno_onda@yahoo.es