cox hyper-saline-cold-shock
DESCRIPTION
TRANSCRIPT
Hyper-‐Saline Cold Shock Treatment of Overcatch (and fouling and parasites
and ..., and cold chain entry)
The Super Salty Slush Puppy Bob Cox, Wayne O’Connor, Peter
Kosmeyer, Kyle Johnston & Mike Dove
Why?
and more whys
and what have we done to fix?
we’ve tried waxing
we know the Japanese farmers roll in salt and we’ve seen the Canadians farming oysters under ice
we’ve tried drying
we’ve tried cooking
and someGmes we’re too late doing something before harvest
Is there a beJer way?
Immersion Quick Freeze – as used on fishing boats
iniGal trials on oysters look promising
• nobody scalded in the effort • 100% effecLve • large margin for error
(compared with the “3 count” a huge margin)
• opportunity to take on the water
• Harvey Calvert is looking like he needs a new hobby
So …
let’s build a prototype
how did it go?
The results: • Controls 0 loss • No loss of treated stock • 45 sec > 90% effecLve • 75 sec 100% effecLve • CondiLon unaffected
The tests: • On land, Commercial stock, Seapa
baskets 100 oysters/basket • Pacific oysters (65 mm) overcaught
with PO (22mm) & SRO (14mm) • 0, 45 or 75 sec (N=10 baskets) • Returned to the lease and checked
aeer 7 days • Tested for survival & condiLon
(macro & CI)
what else can it do?
Barnacles B. trigonus & A. variegatus: Dead in 15 sec
Flatworms Imogine mcgrathi: Dead in 15 sec
Mudworm
Results inconclusive due to lack of affected stock to test however extension of results of tesLng of what we could and known treatments indicate likely favourable outcomes but expected to be dependent on salinity, immersion Lmes and in-‐tank agitaLon
Hairy Mussels
Take a bit longer to kill But sLll dead before damage to host
further work The list is long and includes: v Pushing the limits on: • how fast and slow product can be moved through and sLll deliver results • temperature range (in theory should be able to get to -‐30⁰ if we wanted to actually freeze whole shell, and at the other end is it sLll effecLve at -‐10⁰ as that would make it cheaper providing duraLon didn’t increase exponenLally) • impact of agitaLon -‐ will simple plunging achieve the same outcomes • return to water – will on-‐board treatment with immediate return to water improve treatment performances v Mudworm – while indicaLons are good, the claim of cold shock as an absolute killer in all circumstances is not yet being made v Ideal treatment windows and can they be overlapped for purpose (overcatch treatment with pest and/or fouling treatments) v Will the baskets take it? (SEAPA has been tested and has proved fine) v Impact on bacterial load via treatment on entering route to market and extension of shelf life (in and outside oyster) v ApplicaLon for whole shell freezing for sale and export condiLons saLsfacLon (USFDA & EU) v Efficacy of treatment for alternate tank systems (eg retro-‐fimed cookers) v CosLngs – What opportuniLes to do bemer? for the prototype and assuming it’s the fourth level of treatment (aeer vacaLng known overcatch areas, variable height systems to lie/lower out of catch zone, and holding in high energy water for maximum rumbling) and therefore required only once every four years the cost is esLmated @ $2.85 per thousand [or $4,200 for oysters with a market value of $1,000,000]. v What would you like to see …
Copies of the full report are available, I have some hard copies with me and can email it if you let me know [[email protected]] or you can access it on the OT site. Opportunity also exists to see the machine in operaLon at Port Stephens (and you’re welcome to bring your own oysters to test performance).