Title

Factors influencing the mortality of dugongs in shark nets

Objective

To identify factors influencing the mortality of dugongs in shark nets.

Relevance

Carcass records suggest that the mortality of dugongs is higher in the months July through October than at other times of the year. It is not known whether this is due solely to the seasonality of fishing operations or to seasonal influences on dugong behaviour. Investigation of the temporal trends in the pattern of mortality in shark nets (which fish for 24 hours each day for most of each year) provide an opportunity to investigate this problem.

Feasibility

Excellent records are available of the capture of dugongs in the Queensland Shark Protection Program since the early 1960s including the number caught for each net location, location and length of net and date of capture.

Methodology

A desktop study of the records of the Queensland Shark Protection Program could investigate factors associated with the probability of a dugong being caught in a shark net. Potential independent variables that could be investigated include: location of net, length of time location was netted, time since last removal of net, year, month within year etc.

Approximate cost

$5000

Time required

Two months