Freshwater Mussels Velesunio ambiguus (Harvesting-Packaging-Receiving)

Mussels reproduce naturally in our ponds and dams. We harvest them over summer when the water is warm by feeling for them with our hands. Mussels bury themselves in the mud with their valves upright to take in and spit out the water they filter. As you run your hand along the dam bottom you feel the raised smooth shell of the mussels. We just pluck them out and place in a hessian bag. A normal harvest is 2000-10,000 mussels. A harvest may also be assisted by dropping the water level in the dam to make access easier.

Hessian sacks of mussels being transported from the dams to the packing shed

Mussels are harvested then taken to the packaging shed and sorted on the sorting table. They are sorted into sizes in batches of 500.

We harvest all size mussels from the dams, we can’t tell if small or large we just harvest and sort later

We sort and grade our mussels in the packing facility then store them in trays within our ponds. We have two sorts of trays, stationary trays that are on the floor of the pond. These trays are in our static water level, fish broodstock ponds. These plastic mesh trays are 2.5 metres long by 800 mm wide.

Floating cages are suspended 500 mm below pontoons

The other type of trays we have are suspended trays. These trays are 3 metres long by 800 mm wide and sets of 2 are suspended 500 mm below the surface under polly pipe pontoons. Floating trays are located is our sediment ponds and storage dams. These ponds and dams fluctuate in water levels but the floating cages just move up and down with those fluctuations.

From the trays we scoop them out as required for our weekly orders. Currently we only have storage trays for 10,000 mussels. Consequently we regularly sell out over winter, and we do not start harvesting/restocking our trays till mid-late September when the water starts warming up again.

We scoop mussels from the holding trays into baskets, carry to packaging shed and sort/count them on the sorting table

When required, mussels are easily scooped from the holding trays into shopping baskets then transferred to the packing shed for counting. Mussels are emptied onto a sloping, stainless steel table and counted into batches of 10. When we get 10 piles of 10, we add 3 which the customer receives free of charge. This additional 3% allows for any losses in transport.

Mussels counted into 10 batches of 10 plus 3 extra

Each batch of 10 x 10 + 3 = 103 is placed into a prawn crate.

A prawn crate with 103 mussels being readied for sale

The mussels are then washed in fresh water to clean their shells and wash off any mud and crud.

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Each tray of 100 mussels is then place into a recirculating aquaculture tank for storage until ready for pack and despatch to the customer.

We have 2500 litre rounds plastic holding tanks in the old Port Stephens facility
Our stainless steel holding tanks in the new temperature controlled purging/packaging facility at Port Stephens

Australian Silver Perch and Freshwater Mussel Hatchery only sells bulk loads of freshwater mussels. The minimum purchase is 100 mussels. 200 mussels can fit in a hessian bag.

Each batch is packaged into a hessian bag. The hessian bag keeps the mussels together and limits them rattling around in transit.

A hessian bag containing 206 mussels

We then place the hessian bag in a foam polystyrene box. The foam box is an esky, we add a twin gel pack that is wrapped in bubble wrap. This keeps the mussels cool in transit. The foam box is sealed, this retains the moisture in the box and the mussels are good for around 4 days in transit during summer and 7 days in winter. We despatch by Star Track Express and all of NSW/Qld/Vic/SA can be delivered within this time frame.

Twin gel packs are wrapped in bubble wrap

If you only order 100 or 200 mussels then we will pack the box with wood wool to stop the mussels rattling around in the box. The hessian bag keeps all the mussels together helping them to not smash against each other. We mark the boxes fragile but once in transit we have no control, if the box gets broken the hessian sack will ensure no mussels are lost.

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We can fit up to two hessian bags of mussels in the one foam box. Please be warned; a foam box with 400 mussels weighs 20kgs. When we fill a box with 400 mussels no other packaging is required.

412 mussels in a box

When you order freshwater mussels you get a mixture of sizes, small ones up to large ones. The large ones are mature ready to breed right away. Mussels are long lived animals and most expect they live for 30 years plus. The trouble is that you do not know how old the large ones are, as once they reach a large size they don’t grow in size any more, they could be 30 years old and could die of old age next year or they could be only 20 years old and have another 10 years ahead of them ( who knows???).

The mussels you receive are a mixture of large and small ones

On the other hand the small ones we know are young and have another 20-30 years ahead of them as breeding stock. These small ones will survive and be your breeding stock for the next 20 years plus so very valuable to you in the long run.

Having large ones ensures you have breeding stock immediately. Having small ones ensures you have breeding stock for the next 20 years plus.

Having small ones ensured you have breeding stock for the next 20-30 years. The mussels you are buying are the base broodstock and reproduction is the key to ongoing excellent water quality.

The foam box is sealed and addressed to our customer. We deliver the box to Star Track Express in Newcastle 2300 and it leaves that depot at 6 pm that evening. For most east coast major towns its overnight or 2 days (NSW, Vic, Qld). Places like South Australia can be up to 4 days.

We typically despatch on a Monday and you get Tuesday, Wednesday or Thursday with an extra day Friday up our sleeve if Star Track has a whoopsie.

You can check your delivery time online at : https://startrack.com.au/

Just go to “Calculate transit time”

Sender location is Newcastle NSW 2300

Put in your suburb

Click “Express”

Change “Arrival Date” to “Despatch Date”

Click on the date and put in a Monday

Hit “Get a transit time” and see how long they recon it will take to get to you. Star track is pretty good, many times it will say 2 days but you actually get it in one. Some areas are 4 days but that is no problem, the mussels are good for a week in the box (so long as not a heat wave).

Once you receive you mussels, just open the box, remove the hessian sack. Open the sack up and tip your mussels into your dam or pond. Mussels have a hard thick shell that protects them from thermal sock so no acclamation required like you would for fish. That said if it’s the heart of summer and your water is super-hot, or winter and freezing cold then just dip your sack in the dam first and then wait 2 minutes before you release.

Your mussels have a foot that they will use to move around the dam. Wherever you release them is probably not where they will stay, that said some take a week or more before they get active. Best to release them in at least 600 mm of water and tip them out so they are beside each other rather than in a pile on top of each other.

Good luck with your mussels

Cheers

Rob

New Yabby Season Begins

The blue claw yabby Cherax destructor is a robust, highly fecund species, with fast reproductive cycles, very early maturity and multiple breeding per year. Cherax destructor is a commercially aquacultured species, plus an invasive species outside its natural range. A highly prolific species is advantageous for commercial aquaculture but alarming as an invasive species. The major Yabby farmers don’t need a hatchery to produce their offspring, for most farms the abundance of offspring is the problem as all the juveniles consume resources need to grow large yabbies.

The Yabby Cherax destructor
The Yabby Cherax destructor

Across Australia the breeding season for yabbies (Cherax destructor) has begun. Here at AustSilvers, our Port Stephens yabby farm we started seeing the first berried females in mid August. Just the odd one but a good indication that the season will be early and strong. At our Dubbo farm yabbies started berrying up in early September even with the low water levels. Now in late September both here and across the whole of Australia yabbies are starting to breed.

Berried Female Yabby
Berried Female Yabby

In all western drainages of NSW the common yabby Cherax destructor, occurs. Generally considered a lowland species this is not the case. It occurs from 12 m to 1240 m a.s.l. (AABio data base) and is found in all western drainage streams of NSW. Even in the streams above 1000m water temperatures in late September rise over 10 degrees C and yabbies will be active and start breeding.

Breeding is triggered by two factors, rising water temperatures and increasing daylight lengths.

Freshly laid green yabby eggs
Freshly laid green yabby eggs

We call females with eggs “Berried Females”. This refers to the eggs which look like berries. The eggs are not only shaped like a berry they are also coloured like a berry. When first laid they are green/olive in colour, but as they mature they darken to a blackberry colour.

Yabby eggs nearly ready to hatch
Yabby eggs nearly ready to hatch

Eggs are soft and watery when first laid under the tail. If you force open a tightly curled tail the eggs may just run out. The female cements the eggs to the pleopods or swimmerets under the tail. There are eight pleopods under the tail, all will have eggs attached if all is right with the world.

Yabby eggs attached to swimmerets
Yabby eggs attached to swimmerets

Yabbies breed based on age or maturity not size. Usually they need to be at least 6 months old to breed. Very old yabbies can be small or very young yabbies can be very large, it all depends on habitat conditions and to genetics of the individual. Eggs are oval in shape typically 2-2.5m long by 1.5-1.7m wide. The larger the yabby the more eggs it can physically fit under the tail. Clutches vary from 80 eggs for a small yabby, to over 1000 for a larger animal. Typically they can breed twice or more times per year.

7 gram yabby = 74 eggs

10 gram yabby = 80 – 130 eggs

20 gram yabby = 70 – 154 eggs

30 gram yabby = 170 – 250 eggs

40 gram yabby = 350-450 eggs

50 gram yabby = 710-1000 eggs

Berried female Cherax destructor are very aggressive, they are excellent mothers and will fight viciously to protect themselves and their valuable cargo of eggs. Be very cautious if handling berried females.

Yabby hatchlings hanging onto swimmerets
Yabby hatchlings hanging onto swimmerets

Commercial yabby farms in NSW are fenced to ensure their yabbies don’t escape into the wild, but average people with farm dams don’t fence them so yabbies can breed in the dams till they overpopulate them. When this occurs the yabbies start cannibalizing each other. The whole dam population goes into war mode with every yabby fighting for survival against its cohorts. When rain occurs the yabbies will wander from the dam looking for safer living conditions. Tens of thousands my wander, most will not find safe refuge but some will and they will breed up and a year or so later next rain event off they go again. Yabbies are one of the few species other than man that is increasing its area of domination across the planets surface.

The negative impacts from translocated populations of Cherax destructor in other parts of Australia have been discussed by various authors. One of the best ways for those with yabbies in their dams is to not allow them to overpopulate. Regular harvest and consumption of your yabbies helps to keep them in check.

Cooked yabbies ready to eat
Cooked yabbies ready to eat

We catch our yabbies by either opera house traps or super yabby nets. The opera house traps are not the normal ones available with a ring. These are special commercial traps without a ring and only for use on private or commercial properties. Commercial farms use this type trap because they catch everything and once caught it’s hard for the animals to find their way out. These commercial traps are available from RBM Aquaculture but they are not for use in public waters. Opera house traps are used to catch small quantities, 10-20 kgs etc.

Yabbies captured by opera house traps
Yabbies captured by opera house traps

If you want to catch big loads 20-100kgs then we use the super yabby trap. Again a commercial trap for commercial harvests. Used by yabby, marron and redclaw farmers these are the quickest easiest way to harvest large volumes of crayfish. Available from RBM Aqua but again not for use in public waters.

Check your states regulations re the traps you can use.

If you want to buy yabbies. Yabby Dam Stock are available year round from AustSilvers. We despatch by Star Track Express. A box can fit 200 dam stock yabbies, they are big enough to look after themselves, old enough to start breeding and small enough they don’t wander from the dam. Dam stock yabbies are $88/100 and delivery is $66 to your door, eastern States only. Add an additional $10 for SA. Just send an email to enquire: EMAIL

Dam Stock Yabbies
Dam Stock Yabbies

Cheers, Rob