Here’s a start towards a Shark Solution

Words by Jed Smith

As the world’s leading scientists congregate in Sydney to figure out a solution to the shark problem, here’s a no-brainer of a solution: How about a conclusive study? While sharks have been protected around Australia, and indeed much of the world, for 20 years now, we’ve never had a single scientific fact about shark numbers, their collective behavioural patterns, breeding patterns or migratory patterns to draw on.

“Study into Great White Shark populations is very difficult given the uncertainty about their movements, the uncertainty about rates of emigration and immigration from certain areas and the difficulty in estimating the rates of natural or fishing mortality,” explains the Australian Department of Environment, adding, “Accurate population assessments are not yet possible for any region.”

And yet authorities still saw fit to lift Great Whites onto the protected list as early as 1982 in South Australia and by 1995 in Queensland, Tasmania, Victoria and Western Australia (they were declared protected at a federal level in 1999). The data used to put them there is questionable to say the least. Specifically, evidence given over by fisherman in the form of game-fishing statistics, commercial by-catch and capture rates in shark nets. None of which rates as scientific, given the countless variables and unknowns that could have skewed the findings. Further confusing the situation was contradictory anecdotal evidence presented at the same time suggesting the juvenile Great White population was on the increase in regions of Victoria.

Just last month was Australia given its first “provisional” data on Great White Shark numbers courtesy of a CSIRO report. It put the number of adult whites along the east coast at between 750 and 1200, though it’s a long way from conclusive.

“As we get more ­samples, (adult) numbers are tending towards the lower end of this range,” Barry Bruce, head of the National Environmental Science Program, said.

“The number is smaller than we thought it may be — but without knowing what the number was in the past, the significance of this is hard to tell.”

“What it does not yet tell us though, is whether the population is going up or down.”