Aquaculture; improving????
- Thread starter islandboy
- Start date
So if there are no sea lice in the farms because they have been cleaned off, were does this lice come from??? Why would you need to clean the smolts??? They come from the hatchery delivered sea lice free.
2 part answer to your question, Rico:
1/ H2O2 (hydrogen peroxide) bath treatments remove motile adults & subadult lice off farmed fish and likely kill the attached chalimus stages - but likely not the egg strings from gravid female lice. Not sure what happens to those dislocated motile lice along with the egg strings and any other motile lice attached to cages/nets. Maybe you can provide insights there?
2/ If FF fish are re-infected w sea lice from wild fish (verses adjacent farms) - what does that tell you about the OPEN net-cage technology being able to mitigate wild/cultured fish interactions? The lice don't go just one-way into the net-pens - they go both ways.
1/ H2O2 (hydrogen peroxide) bath treatments remove motile adults & subadult lice off farmed fish and likely kill the attached chalimus stages - but likely not the egg strings from gravid female lice. Not sure what happens to those dislocated motile lice along with the egg strings and any other motile lice attached to cages/nets. Maybe you can provide insights there?
2/ If FF fish are re-infected w sea lice from wild fish (verses adjacent farms) - what does that tell you about the OPEN net-cage technology being able to mitigate wild/cultured fish interactions? The lice don't go just one-way into the net-pens - they go both ways.
Yous didnt answer the question......
How do fish farms get sea lice on them if the farms are lice free??? How do smolts get lice on them when the farm is lice free?
Its because salmon do not produce an immune system for lice till there second year. Pink salmon spawn in there second year. They are the carriers. You will never get rid of wild sealice AA just the farmed ones which is what you have been asking for. Farms companies have delivered and your are grasping......
How do fish farms get sea lice on them if the farms are lice free??? How do smolts get lice on them when the farm is lice free?
Its because salmon do not produce an immune system for lice till there second year. Pink salmon spawn in there second year. They are the carriers. You will never get rid of wild sealice AA just the farmed ones which is what you have been asking for. Farms companies have delivered and your are grasping......
Dave H
Well-Known Member
Not from the Washington event, but back in the 90's there were at least two incidents of Atlantic salmon escapees successfully spawning, in the Tsitika and the Amor de Cosmos rivers north of Campbell River. Juveniles were discovered in both streams and analysis showed they were wild juveniles.
This was during the period before farmers had beefed up their net systems to avoid escapes and there were a lot of Atlantics being found in various rivers on the island. Amongst my fishing pals I'm one of the few who hasn't actually caught one, but I know of at least 40 that have been caught, including right here in the Campbell itself. Lots in the Salmon river and many on a few small west-coast streams back then.
I realize farmers have improved their systems nowadays, plus I believe that Atlantics are poor colonizers, given the historical records, but they can escape and spawn successfully, of that there is no doubt, given the juveniles that were found in both above-named systems.
You also need to grasp the fact that virtually no government agency is looking for Atlantics in freshwater these days, so nobody really knows whether there have been other instances of successful spawning or not, but they can and they have, and should there be further disastrous events/escapes, there is no guarantee future spawning won't happen.
Take care.
Actually Rico - I did answer your question. But - again - it may not be the answer you wanted. That lice flow both ways.
Speaking of grasping - If you want to claim that "salmon do not produce an immune system for lice till there second year" - maybe you could produce some science to support your assertion? along w some science to show that farms can't get re-infected either by adjacent farms or by lice not on the farmed fish?
Speaking of grasping - If you want to claim that "salmon do not produce an immune system for lice till there second year" - maybe you could produce some science to support your assertion? along w some science to show that farms can't get re-infected either by adjacent farms or by lice not on the farmed fish?
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Birdsnest
Well-Known Member
Good post DaveH. What you have said there is true about escapes however considering historical Atlantic salmon introduction attempts over the last 100 years on the west coast and the massive amount of escapes in the 90s it pretty safe to say that the risk of re-establishment of Atlantic salmon here in the pacific west coast both hatchery and farm stock is less than minimal.
https://vancouversun.com/news/local...c-salmon-introduced-to-b-c-streams-since-1905
cuttlefish
Well-Known Member
Quite the rig. I hope it works and proves worth the investment and continuing operating cost. 50 gallons/hour for each of those four Cummins gensets to run the diesel/electric propulsion system. http://www.polandatsea.com/crist-yard-launched-live-fish-carrier-aqua-tromoy/
Time will tell but based on the data sets posted on the Mowi website; https://mowi.com/caw/sustainability/sea-lice-reporting/, it looks like they still have some fine tuning to do. Definitely doesn’t yet get rid of all the lice on the farmed salmon treated so far. Makes me wonder if the remaining lice could develop resistance to fresh water. Scary thought...
cuttlefish
Well-Known Member
A shot of the new big rig at Point Hope Shipyard with the Orca Warrior an early Mowi West well-boat in the foreground. Aquaculture improving?
wildmanyeah
Crew Member
I assume you know sea lice are in brackish areas like the mouth of the fraser river. So they have some resistance to fresh water
Freshwater treatments should be used sparingly
https://www.fishfarmingexpert.com/article/freshwater-treatments-should-be-used-sparingly/
Strangely enough - on the risk of establishment of self-replicating populations of Atlantic salmon - I agree that it is low risk as long as 2 conditions are maintained:
1/ The numbers of Atlantic salmon that escape remain low, and
2/ The populations of natal steelhead remain sufficient in adjacent creeks.
Volpe confirmed that the species and lifehistory stages most likely to compete with Atlantic salmon juveniles is steelhead - as they seem to prefer similar rearing habitat (somewhat faster water).
For me - the risk is instead from new, novel disease transfer to resident stocks.
1/ The numbers of Atlantic salmon that escape remain low, and
2/ The populations of natal steelhead remain sufficient in adjacent creeks.
Volpe confirmed that the species and lifehistory stages most likely to compete with Atlantic salmon juveniles is steelhead - as they seem to prefer similar rearing habitat (somewhat faster water).
For me - the risk is instead from new, novel disease transfer to resident stocks.
cuttlefish
Well-Known Member
So, if they know that some stages of sea lice are naturally tolerant to freshwater then I guess they wouldn’t expect the treatment to result in farmed salmon free of lice. Just lower levels.
Birdsnest
Well-Known Member
Which "new" "diseases" specifically or are you referring to?
wildmanyeah
Crew Member
This is what we are talking about correct? A Virus
Unmasking a Salmon Virus
https://www.hakaimagazine.com/news/unmasking-a-salmon-virus/
The convenient aminisa of confusing a virus and a disease seems to be a talking point all to common to the paid ENGO advocacy. Not surprising that paid ENGO pundts always push this. I guess their large donors pay for this kind of obfuscate.
Unmasking a Salmon Virus
https://www.hakaimagazine.com/news/unmasking-a-salmon-virus/
The convenient aminisa of confusing a virus and a disease seems to be a talking point all to common to the paid ENGO advocacy. Not surprising that paid ENGO pundts always push this. I guess their large donors pay for this kind of obfuscate.
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No sorry..... it's not a hydrogen bath...... there is nothing left over. No eggs and all sizes of louse are completely removed from the ocean. And sorry but your wrong.... it is now a one way into the sea pens. Please read and google the octopus boat. It been the UK now for a few years.2 part answer to your question, Rico:
1/ H2O2 (hydrogen peroxide) bath treatments remove motile adults & subadult lice off farmed fish and likely kill the attached chalimus stages - but likely not the egg strings from gravid female lice. Not sure what happens to those dislocated motile lice along with the egg strings and any other motile lice attached to cages/nets. Maybe you can provide insights there?
2/ If FF fish are re-infected w sea lice from wild fish (verses adjacent farms) - what does that tell you about the OPEN net-cage technology being able to mitigate wild/cultured fish interactions? The lice don't go just one-way into the net-pens - they go both ways.
These are my as you say insights.
Birdsnest
Well-Known Member
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