It’s yabbie dabba don’t

RECENTLY, I had the opportunity to collect a few yabbies (cherax destructor) with a friend, who is a licensed collector of these crustaceans.

His role is to supply the Platypus enclosure at Beauty Point with enough of the yabbies to help feed the display platypus populations.

To say, it was an interesting exercise was an understatement, for collection is no simple matter. The chap with whom I went is a scientist with a passion for entomology, so it was a great opportunity for me to learn more about aquatic insects and the role of cherax destructor in Tasmania.

They have a dark blue or green-brown body, with an abdomen smooth and as wide as the thorax. The first pair of limbs is large with claws. They are up to 25cm long from head to tail tip.

In areas that dry up, yabbies dig and hide in a burrow, reemerging when water returns. They breed from October to March, and they eat mostly plant matter.

They are found mainly in eastern mainland Australia and Tasmania and they like ponds, farm dams, lakes and small creeks.

In 2017, the species was found in Lake Lynch in the Central Highlands and while they were eradicated by the Inland Fisheries Service they continue to remain a problem in other waters.

The movement of this pest crustacean is probably done by people, who move them from one water to another, which is an illegal practise.

For those who don’t know, yabbies such as CD have the potential to out-compete native crayfish and due to their burrowing habits, and have been blamed for earthen dam failures.

An indication of the presence of CD is that the water is usually turbid and quite often, cast shells or claws can be seen in shallow waters for the species is also preyed upon by herons, kookaburras and fish.

Besides water turbidity, the CD also promotes algal blooms, erodes stream banks and facilitates further invasion of natural waterways.

It may also reduce or destroy aquatic vegetation. Habitat alteration and competition may displace endangered native burrowing crayfish.

also carries diseases and parasites and is susceptible to the crayfish plague of the Northern Hemisphere.

They are classed as a feral pest and under the Inland Fisheries Act 1995 are prohibited from importation, possession and capture.

Those found contravening this part of the Act can receive fines up to $13,000.

Some time ago, a man from NSW was found to be in possession of the cherax at the

Great Lake plus other banned products and received a fine of $8000 and had to fly in for court appearances each time, which proved to be a costly exercise.

The simple method is not to fish for the species and certainly don’t transport them from one location to another.

Along with other species, such as the long-necked tortoise, gambusia and many other feral species, Tasmanian waterways are struggling withCD out the interference of water users transporting illegal products.

On a happier note, fish are being caught everywhere and Canal Bay at the Great Lake is no exception, with many boaters and bankside anglers doing very well of late, spinning all manner of lures.

One water fishing well is Woods Lake which would have to be the standout water for Tasmania at this time.

Offshore, mako shark are on the move with blue sharks and even the odd albacore being caught.

Finally, I’d like to take this opportunity of thanking everyone who helps me put this column together each week, and to all our readers, have a happy and safe Christmas.

Make sure to check your gas cylinder on your life vest if it has one, as they can work loose or might even need a tighten if brand new.