Preliminary results from an exploratory translocation study at the Natural Marine Reserve of Miramare (Trieste, Italy)

摘要

One of the conservation precautionary measures applicable to overexploited species is to implement protected population through translocation of exogenous individuals. The European lobster (Homarus gammmarus L. 1758) and the brown meagre (Sciaena umbra L. 1758) are species under strong fishing pressure. In summers 2001 and 2002 we released four translocated lobsters and two translocated brown meagres inside the Natural Marine Reserve of Miramare, where the species are naturally present. The spatial behaviour of the released animals was monitored using two different acoustic tracking systems (Track28 and VR1 receivers; Vemco Ldt). On the base both of bibliography and of our preliminary experimental outcomes, the lobsters were tagged by gluing the pinger to the dorsal surface of the cephalothorax and the brown meagres were tagged by implanting the pinger in the peritoneal cavity. All the animals, both lobsters and brown meagres, disappeared from the detection range of the hydrophones after a variablenumber of days (2-16 days of continuous monitoring). We suppose that they did not colonize the site, leaving the protected area. From the methodological point of view, VR1 mode proved to be a suitable tool to evaluate the colonisation of an area by transferred animals.