Blog | 29th Aug, 2011

All about yabbies: Environment Victoria volunteer Kaye Cleary takes a look below the surface

Where are our yabbies going and are they getting smaller? Do you have childhood memories of sitting in the shade by the waters edge, pulling out yabbies; big monsters, fat-tailed mums-to-be, and small ones on their way to growing up?

An unquestioned pleasure of childhood… yabbies, like most everything else around me at that time “were there” for the taking. And have you seen how yabbies have been emerging from their dormancy with the recent floods? These yabbies are “big” but not as big as they used to be. Is this simply childhood imagination, like re-visiting the house we grew up in, the past house loomed larger in memory than what we see before us?

So I started to investigate. Yabbies are fascinating with their boom-and-bust populations – they can survive years of drought by burrowing into the wet mud and remaining dormant until the dry spell breaks. When the rains return, a formerly dry creek or lake is suddenly teeming with yabbies, large catches quickly follow and then the population equally suddenly vanishes. Why? The NSW Dept of Primary Industries doesn’t know – they tell us that the disappearance cannot be accounted for solely by heavy fishing – instead the reasons are “not properly understood”. The IUCN lists the common yabbie as “vulnerable” in their Red List of Threatened Species but not, as yet, “endangered”… so concerns about the sustainability of populations have reached the international watchdog.

Although yabbie population dynamics are so poorly understood, the Victorian government recently granted a 50% increase in the yabbie quota for recreational fishers. While we enjoy yabbie on the menu, most yabbies are destined as bait for fishing… bait caught by the bucket-full! Fisher people can now catch up to three 10-litre bucketfuls per day in Victoria, more than in other states. Surely we need to find out more about this species before we allow increased quotas and provoke a downward classification from “vulnerable” to “endangered”.