there's a yabby on my barbie
Everyone who grew up in Australia seems to have a fond memory of being a kid and catching yabbies....summer, a dam or stream, wet trouser legs, squishy mud between toes and the occasional nip to the finger. That said, yabbies are a little under- represented on restaurant menus, but they are popping up in (South Australian) farmers’ markets in greater numbers and more frequently lately.
The prevalent species in Australia is Cherax Destructor. It is an endemic species to most south eastern states. They are hardy little guys who are gaining popularity in aquaculture. The breeding cycle is short with a female producing over a couple of hundred eggs up to three times a year. The average table sized yabby (100 to 160 g) reaches weight in around 6 months.
Interestingly the common yabby is classified as a vulnerable species by the World Conservation Union but the listing is somewhat questionable; surprisingly little research on the species has been undertaken. A notable restriction is that berried (fancy word for pregnant) females must be returned to the water, (so if you see roe attached under the carapace then chuck it back); and bag limits of 200 per day apply in South Australia to preserve wild stocks, but stock levels for farmers is the least of their problems.
Jane Nott of Galloway Yabbies is a former pig, turkey, emu and sheep farmer who turned her hand to farming yabbies in the Fleurieu Peninsula a few years ago. She explains, “It’s a matter of control rather than management;” populations can get out of hand and the biggest challenge in her business is demand, not supply. It’s an interesting scenario when so many of our aquaculture industries struggle with breeding and mortality rates (antibiotic use is not uncommon) to grow species that may not be perfectly suited to our climate and conditions, yet ignore endemic species that thrive.
The species are nocturnal detritivores (which is a posh way of saying they stuff their faces with anything at night, so I guess they are like the bong-smokers of the aquatic system!). They eat algae and plant remains but are good dam cleaners and will eat any dead fish or animals that end up in the dam; this makes them a very economical source of protein as they require very little “inputs.”
Again when you compare the protein conversion of some of our aqua culture ventures that require 20 odd kg of protein i.e. fish meal to make 1 kg of protein for the table you have to scratch your head. It just doesn’t make sense as the overt use of fish meal basically translates to less small fish remaining for us/other fish to eat. Jane feeds her kids predominantly lupins, meadow hay and carp so they are hardly competing with us for valuable food supplies.
The biggest challenge she faces is preventing shags from eating her yabbies, they are efficient predators so dams have to be netted. Opera nets are used to split populations (boys are put in separate dams as they’re what is used for meat supply). But yabbies will crawl across land, so the occasional girl will get herself out of the dormitory and in with the guys that are slated for market.
Jane has a hectare of water available and is currently running at half capacity with 4 or 5 ponds stocked at a time. The ponds are periodically allowed to dry out; this is basically all that’s needed to clean the pond and eliminate nitrogen causing bugs which effect productivity.
A tribute to the species’ resilience is its ability to tunnel into the banks and lay dormant for long periods (an adaptation to our natural drought cycle), so when the dam is refilled and restocked there will always be a few remaining squatters lurking and ready to resurrect their home.
You will start to see a steady supply of yabbies when spring is underway, as Jane explains with water below 16°C there’s not a lot of action in the yabby world. Once the water temperature heats up growth spurts occur and you will notice the yabbies molt their shells to accommodate. It is fascinating to watch them slip out of a dirty old shell to reveal a paper-soft, new paint job.
Generally wild yabbies will have more robust shells and of course they won’t have been purged like market supplies of farmed product (after a day or two in clean water), so there will be more “mustard” in the tract (which is a nice way of saying poo!). I do prefer purged yabbies because you don’t have to peel the back flesh from the body to clean them which seems a little wasteful, you can generally just tug the tract through the body from the tail end while shelling and you have a clean piece of meat.
So back to those “yabby memories…” they don’t have to stop when you stop being a kid. Next Christmas why not skip the prawns, hit the markets and throw a few yabbies on the BBQ and start making some brand new happy memories.