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Author Topic: Another day another virus scare.  (Read 2357 times)

Bassonator

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Re: Another day another virus scare.
« Reply #1 on: April 17, 2012, 02:30:11 PM »

Thanks Aqua. Pretty soon she'll run out of her 15 minutes and she has herself to thank for that.... :o
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Dave

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Re: Another day another virus scare.
« Reply #2 on: April 17, 2012, 03:39:06 PM »

I've crunched the numbers and figure she's at 12 minutes 11 seconds :D
Almost like Crusty Clark, eh Chris?
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chris gadsden

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Re: Another day another virus scare.
« Reply #4 on: April 17, 2012, 03:49:59 PM »

I've crunched the numbers and figure she's at 12 minutes 11 seconds :D
Almost like Crusty Clark, eh Chris?

No David, Alex has been doing this for years, long before you and the others came on board so to speak. ;D ;D ;D

One fine lady that is trying to save our wild fish from what has happened to our precious wild salmon wherever fish farms have been world wide, long before they came to our waters.

Once again, no one from your side wants to talk about that here. :o

Of course when you have a government that seems to want to gut the Fisheries Act along with not doing more in protecting habitat I guess promoting fish farms tells us what we are up against. :( :-[ :'(
« Last Edit: April 17, 2012, 03:52:08 PM by chris gadsden »
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chris gadsden

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Re: Another day another virus scare.
« Reply #5 on: April 17, 2012, 04:34:38 PM »

No David, Alex has been doing this for years, long before you and the others came on board so to speak. ;D ;D ;D

One fine lady that is trying to save our wild fish from what has happened to our precious wild salmon wherever fish farms have been world wide, long before they came to our waters.

Once again, no one from your side wants to talk about that here. :o

Of course when you have a government that seems to want to gut the Fisheries Act along with not doing more in protecting habitat I guess promoting fish farms tells us what we are up against. :( :-[ :'(
Here is an example what I am saying above, from the CBC.

Moves gut environmental protection, say critics
Environmental groups and opposition parties, however, insist the government is merely giving big energy companies carte blanche by dismantling the checks and balances that protect the environment.

"After slashing funding to the Canadian Environmental Assessment Agency, theyíre now saddling it with the obligation to do more complex reviews, faster, with fewer resources," NDP environment critic Megan Leslie said Tuesday.

"You're going to have less time, less resources from the federal government to actually look at and understand these projects and less opportunity for the public to point out errors and omissions in submissions by proponents," John Bennett, executive director of Sierra Club Canada, told CBCNews.ca.

Green Party Leader and MP Elizabeth May said the moves go farther than what industry stakeholders were asking for.

"This kind of savaging of the environmental assessment process are more about speeding the development even more than the industry needs," May told CBC News Network.

May and Bennett both said the overall impact from the government's move comes not just from changing the rules, but from cutting budgets of federal departments such as Environment Canada, and firing hundreds of scientists who currently contribute to the environmental review process and work to protect Canadians from environmental disasters.

"What's really happening here is that the federal government is abdicating its responsibility and trying to get out of the protecting-the-environment business," Sierra Club's Bennett said. "Why don't they go all the way and shut down Environment Canada and be honest and say, 'We don't give a cupcakes'? Because that's what they're doing."

The government counters that by not reviewing small, minor projects, it can focus more resources on major ones, as well as back up "enforceable" assessment decisions with financial penalties of up to $400,000 for companies that refuse to comply with decision conditions.

David Collyer, president of the Canadian Association of Petroleum Producers, applauded the measures, saying they will address some of the uncertainty companies face over how long their applications take in the existing process.

Collyer said he believes that eliminating agency overlap and redundancy allows for more resources to be directed to assessments of major projects that have a larger potential for environmental impact.

"I don't see anything in any of the announcements that would indicate to me that there's any intention to reduce environmental oversight," Collyer told CBCNews.ca.

"The focus on responsible environmental outcomes, we all expect that and Canadians expect that."

In addition, the Harper government will spend $35 million over two years on marine safety and $13.5 million on pipeline safety to help protect the environment, Oliver said.

That will include requiring double hulls and mandatory pilots on oil tankers, as well as more inspections of oil and gas pipelines.

Dave

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Re: Another day another virus scare.
« Reply #6 on: April 17, 2012, 06:37:01 PM »

Everyday eloquently addressed this question of yours a while ago.  If you don't remember that post, (and I can't find it) it's mainly that your argument is not applicable to Pacific salmon or BC/Washington State salmon farms.
When you speak of other countries harmed by salmon farms do you mean Chile?  No wild stocks there to harm.  Do you mean Norway?  Still awesome sport fishing there if you have deep pockets.  Do you mean Scotland, Ireland and Britain?  I suggest 2000 years of habitat destruction, human population growth and commercial fishing is the main cause of the demise of those fisheries.  But interestingly, according to British angling magazines, this year Scotland had a pretty good salmon season and increased sea trout (anadromous brown trout) populations.
All the problems have arisen when farmed Atlantic's (save Chile where poor husbandry and woefully inadequate environmental standards are the norm) are raised in areas that have wild Atlantic stocks.  Escapes and diseases passed between wild and farmed salmon happened and still are, much like diseases of domestic animals and wild ungulates and birds have occurred in North America.
But here is the important part, Pacific salmon are a different animal and seem to have developed an immune system that is able to withstand the diseases lethal to Salmo species.
If these diseases that Ms. Morton reports on so regularly were indeed an issue, why are there no mortality's among Salmo species? 

I believe we need to pick our battles for wild salmon, and people like you and I and others who fight for them, have much more to fear from overharvesting and habitat destruction than fish farms.  Think pipelines, oil tankers, IPPís, etc, etc

Coffee tomorrow ? ;)


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aquapaloosa

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Re: Another day another virus scare.
« Reply #7 on: April 18, 2012, 07:00:20 AM »

Quote
Everyday eloquently addressed this question of yours a while ago.


This is the post of Everyday's to Chris, AF, and Holmes:

http://www.fishingwithrod.com/yabbse/index.php?topic=28342.msg272510#msg272510  Post # 125

Quote
Look what has happened in other countries Dan, can you give me an answer why it will be different here, no one here has given me an answer yet, maybe it is because they do not have one. Sad

First of all (most important) as said before Chile had no salmon stocks to begin with, nothing was wiped out. Norway has not had any wild stocks wiped out either.

What happened on the East coast may indeed (from my view point) have been caused by farms. But you are missing 2 major factors here:

1) The wild stocks were the same as the farmed fish. This meant that diseases could actually spread from wild to farmed and vice versa. It also meant that if any farmed fish escaped, they could actually spawn in the wild and weaken the genetic pool. This is not the case in our waters, where pacific salmon are very immune to Atlantic diseases and can't produce viable offspring with them.

2) Bio security back then was almost non existent. Farms were extremely clustered and were hot spots for disease. Fish were harvested right on site and blood was pumped right into the water. Brood fish were kept close to smolts, etc. Bio security has become incredibly harsh now. There are different management zones where only 1 age class of fish can be raised at a time. No harvest can be done at sites, and if done on a vessel no harvest water can be put back into the ocean without sanitation. Fines are huge and can result in your licence being pulled, so in short no one does it. There hasn't been an outbreak of ISA or other disease since bio security protocols have been raised.

If you are referring to their Cod fishery (and I'm sure this applies to their Atlantics even somewhat as well) that was strictly over fishing that did them in. Cod are a totally different species and inhabit different niches, etc. Farms had nothing to do with their demise, and unless you can provide some type of scientific paper (or anyone else) that is what most people would go off of.

Quote from: alwaysfishn on November 08, 2011, 10:56:07 PM
Quote
See it's untrue statements like that that try to dismiss the issue that get me riled! Both Chile and BC are raising masses of salmon in an ocean where the waste, diseases and medication effect the environment they are in. There is no difference in the environment. It's only a matter of time before our environment is negatively impacted the same way it has been impacted in Norway and Chile.

Once again, no impact in Norway and especially Chile which had no stocks to begin with, although anti farmers would love you to believe that.

Waste? How is the farmed salmon waste any different than wild salmon waste? They are fed the same stuff and produce the same waste? Even if you argue about the food waste going into the ocean, it was taken out of the ocean to begin with!

Diseases? I don't know of hardly any diseases (if any at all) that can live more than 48 hrs in the water. Once again, diseases effecting Atlantic's hardly ever effect Pacific salmon as they are more hardy and have developed immunities to many of the diseases.

Medication? This really annoys me! Anyone can go online and find the actual amount of antibiotics administered to farmed fish. 2009 it was a whopping 528 g per Metric Tonne! I guess by your standards that might be a lot (enough to pollute the ocean?!)? It would also be significantly less if it weren't for having to treat brood stock fish. The net pen fish receive maybe 10% of that and only in extreme cases where nothing else can be done.

Holmes

The fact that they cannot produce any results shows that levels were low to begin with.
It also brings to question why they did not keep samples properly, when it is mandatory that the CFIA do tests as well.
It all seems fishy to me. Even if low levels were detected to begin with, once again that does not mean that the fish was infected, just means it was carrying it.

Also about the feed.
As said before, there are strict rules on how much can be taken for fish meal. If numbers of food fish are not good, there is no catch allotted. Much of this also goes into dog and cat food, do you own either of those? If you are you are also taking "food" right "out of the mouths" of wild fish. As said before, salmon ranching taking part in China releasing close to a billion fish right into the ocean is causing much more damage than netting out an allotted amount of food fish. I still don't get why no one is in an uproar about the salmon ranching? Less and less wild fish, more and more "enhancement" (which are all taken as food over there) and no one points a finger at that?

Cheers,
Dan
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Sandman

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Re: Another day another virus scare.
« Reply #8 on: April 18, 2012, 08:31:53 PM »

A particularly liked this quote from one of aquapaloosa's links above:

[quote author = http://protestingtheprotesters.wordpress.com/2012/04/14/fear-mongering/]
HSMI appears to be a severe disease with elevated mortality, morbidity close to 100% and prolonged duration.Ē

I donít have a bachelors in science, like Ms. Morton, but I donít see where it says that Atlantic salmon can recover from this disease. Morbidity close to 100% is extremely serious, like an outbreak of ebola would be for humans. [/quote]

I think he is right about not being a biologist, because he appears to confuse 100% morbidity (the frequency of disease in a population) with 100% mortality (the instances of death in the population).  His own quote says that mortality is merely "elevated" and that duration is "prolonged" suggesting the fish could survive prolonged periods of infection.
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Sandman

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Re: Another day another virus scare.
« Reply #9 on: April 19, 2012, 05:08:00 PM »

I am not sure how "eloquently" he answered the question, but I wonder about the subsequent responses that surely followed this post.


This is the post of Everyday's to Chris, AF, and Holmes:

http://www.fishingwithrod.com/yabbse/index.php?topic=28342.msg272510#msg272510  Post # 125

First of all (most important) as said before Chile had no salmon stocks to begin with, nothing was wiped out. Norway has not had any wild stocks wiped out either.

What happened on the East coast may indeed (from my view point) have been caused by farms. But you are missing 2 major factors here:

1) The wild stocks were the same as the farmed fish. This meant that diseases could actually spread from wild to farmed and vice versa. It also meant that if any farmed fish escaped, they could actually spawn in the wild and weaken the genetic pool. This is not the case in our waters, where pacific salmon are very immune to Atlantic diseases and can't produce viable offspring with them.

2) Bio security back then was almost non existent. Farms were extremely clustered and were hot spots for disease. Fish were harvested right on site and blood was pumped right into the water. Brood fish were kept close to smolts, etc. Bio security has become incredibly harsh now. There are different management zones where only 1 age class of fish can be raised at a time. No harvest can be done at sites, and if done on a vessel no harvest water can be put back into the ocean without sanitation. Fines are huge and can result in your licence being pulled, so in short no one does it. There hasn't been an outbreak of ISA or other disease since bio security protocols have been raised.

If you are referring to their Cod fishery (and I'm sure this applies to their Atlantics even somewhat as well) that was strictly over fishing that did them in. Cod are a totally different species and inhabit different niches, etc. Farms had nothing to do with their demise, and unless you can provide some type of scientific paper (or anyone else) that is what most people would go off of.

Quote from: alwaysfishn on November 08, 2011, 10:56:07 PM
Once again, no impact in Norway and especially Chile which had no stocks to begin with, although anti farmers would love you to believe that.

Waste? How is the farmed salmon waste any different than wild salmon waste? They are fed the same stuff and produce the same waste? Even if you argue about the food waste going into the ocean, it was taken out of the ocean to begin with!

Diseases? I don't know of hardly any diseases (if any at all) that can live more than 48 hrs in the water. Once again, diseases effecting Atlantic's hardly ever effect Pacific salmon as they are more hardy and have developed immunities to many of the diseases.

Medication? This really annoys me! Anyone can go online and find the actual amount of antibiotics administered to farmed fish. 2009 it was a whopping 528 g per Metric Tonne! I guess by your standards that might be a lot (enough to pollute the ocean?!)? It would also be significantly less if it weren't for having to treat brood stock fish. The net pen fish receive maybe 10% of that and only in extreme cases where nothing else can be done.

Holmes

The fact that they cannot produce any results shows that levels were low to begin with.
It also brings to question why they did not keep samples properly, when it is mandatory that the CFIA do tests as well.
It all seems fishy to me. Even if low levels were detected to begin with, once again that does not mean that the fish was infected, just means it was carrying it.

Also about the feed.
As said before, there are strict rules on how much can be taken for fish meal. If numbers of food fish are not good, there is no catch allotted. Much of this also goes into dog and cat food, do you own either of those? If you are you are also taking "food" right "out of the mouths" of wild fish. As said before, salmon ranching taking part in China releasing close to a billion fish right into the ocean is causing much more damage than netting out an allotted amount of food fish. I still don't get why no one is in an uproar about the salmon ranching? Less and less wild fish, more and more "enhancement" (which are all taken as food over there) and no one points a finger at that?

Cheers,
Dan


On the "no impact in Norway",  Lars P. Hansena, and Malcolm L. Windsor,  in "Interactions between Aquaculture and Wild Stocks of Atlantic Salmon and other Diadromous Fish Species: Science and Management, Challenges and Solutions" Journal of Marine Science 63:7 2000,

summarize the findings a third international symposium of of the ICES and NASCO, in Bergen, Norway, 18–21 October 2005. The objectives of which were:
Quote
    to summarize available knowledge of the interactions between aquaculture and wild salmon stocks and other diadromous fish species;

    to identify gaps in current understanding of these interactions and to develop recommendations for future research priorities;

    to review progress in managing interactions, the remaining challenges, and possible solutions; and

    to make recommendations for additional measures to ensure that aquaculture practices are sustainable and consistent with the Precautionary Approach.


Following the keynote session were sessions focusing on genetic and ecological interactions and their management, and on disease and parasite interactions and their management.

Quote
From the session on genetic and ecological interactions, it emerged that:

    Although there have been considerable improvements in containment and reporting, the number of escaped farmed salmon is still very large relative to the abundance of wild salmon...

    . . .Theoretical modelling, comparing wild salmon populations exposed to salmon farming with those not exposed, indicates reduced productive capacity of wild salmon in areas with farms, with the size of the reduction linked to the scale of farmed production. [emphasis mine]

    Genetic change has been observed in some wild salmon populations exposed to escapees but not in others, suggesting that impacts from aquaculture are influenced by the number of escapees spawning and the abundance of the wild fish population in the river. Simulations, based on simplified input data with fixed annual intrusion rates of 20% farmed escapees, suggest that substantial changes can take place in wild salmon populations within ten salmon generations and that these changes may be irreversible.

    Risks are posed by the stocking of cultured fish, and the goals of such programmes need to be carefully considered . . .

    . . .From the session on disease and parasite interactions, it emerged that:

    Increased understanding of all aspects of the biology of sea lice, which has led to better tools for identification of sea lice, is facilitating the development of increasingly effective integrated louse management strategies and may lead to the development of an effective vaccine in future.

    Sea lice infestation pressure from salmon farms is an important issue affecting wild salmonids in many areas. Infestation levels on emigrating salmon smolts are highly site-dependent, and the risk of infestation varies from year to year and with hydrographic conditions, etc.

    Sea trout are highly susceptible to sea louse infestations, with susceptibility decreasing with distance from marine salmon farms.

    For salmon and sea trout, the burden of sea lice is now recognized as a strong predictor of mortality in areas with farms. [emphasis mine]

    Sea louse management has evolved considerably in recent years, but there are concerns about the reliance on a handful of key medicines. Although there have been notable improvements in louse management strategies in recent years, challenges remain if wild salmon and sea trout stocks are to be effectively protected. The use of wrasse may be an important option in integrated louse management regimes.

    It is essential to prevent the further spread of the parasite Gyrodactylus salaris and to eliminate it from infested rivers. . .

  You can read the whole paper here: http://icesjms.oxfordjournals.org/content/63/7/1159.full

On the question of "How is the farmed salmon waste any different than wild salmon waste?"

How about the obvious: wild salmon are not feed antibiotics and pesticides, and they swim around (so their waste is distributed over the entire ocean) whereas farmed fish are fed antibiotics and pesticides and they are not allowed to swim around so their waste is concentrated over a single area of the ocean floor.

On the diseases not surviving more than 48 hours in the water:

Why is that even an issue? Wild fish can swim close enough to the net pens and wild juvenile salmon can swim right through the nets and come in close contact to the farmed fish to initiate transfer.  And of course there is the possibility of infected fish escaping the pens.

« Last Edit: April 19, 2012, 05:10:48 PM by Sandman »
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Every Day

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Re: Another day another virus scare.
« Reply #10 on: April 20, 2012, 03:27:00 PM »

Ok.... I told myself I would stay out of this and I did a good job for a while, but I'm finally done my interviews, my finals, and all my papers and need something to do and the post above kind of irked me so here we go...

1) Sources for this information? I read that whole paper and saw 2 papers quoted... would you consider that reliable? I can just as easily sit behind my keyboard right now and type a paper that long with my own points on how theoretical modelling proves that salmon farms don't have an impact on wild fish and that sea lice are not an issue. Just because a paper is published in a journal doesn't mean it is a good one.

2) Next point... lets re visit that theoretical model. I seem to recall a model produced a few years back saying all pink salmon would be extinct by last year due to sea lice infestation.. Don't remember it? I'll gladly go re find it for you if you would like to argue how accurate theoretical modelling can be.

3) I still have yet to see a single paper that adequately proves that sea lice from farms are killing wild salmon. First off, how can you prove that these fish are getting the sea lice from farms? Many of the studies conducted take their samples hundreds of km's away from farms, yet the farms are the problem? If you expect me to believe that they get infected with the sea lice at farms and then swim hundreds of kilometres away from the farm, how does that prove to me the sea lice are even killing the fish?

Now to go further into the point above. Please don't qoute Morton's and Routledge's paper on the effects of sea lice on pinks and chum. First of all, they used beach seines and hand nets to catch heir fish. Weak and infected fish are slower and come to the top = easier to catch and see = biased results. They also held their barrels off a dock in warm surface water. Stressed and weak fish from capture will always die given more stress, and you're also keeping the fish in a contained environment where they are not able to escape sea lice. If their study encompassed a wild population I might be more prone to believe it. I also might be persuaded into believing their papers if they hadn't predicted that all pink salmon would be virtually extinct by the year we happened to have one of our biggest runs ever.

Here's a paper to read on sea lice not effecting swimming speeds, etc (hopefully you can see it as I'm using library data base), paper info :
Nendick, L. et al. 2011, Sea lice infection of juvenile pink salmon (Oncorhynchus gorbuscha): effects on swimming performance and postexercise ion balance.

http://dd6db2vc8s.search.serialssolutions.com/?ctx_ver=Z39.88-2004&ctx_enc=info%3Aofi%2Fenc%3AUTF-8&rfr_id=info:sid/summon.serialssolutions.com&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Sea+lice+infection+of+juvenile+pink+salmon+%28Oncorhynchus+gorbuscha%29%3A+effects+on+swimming+performance+and+postexercise+ion+balance&rft.jtitle=Canadian+Journal+of+Fisheries+and+Aquatic+Sciences&rft.au=L+Nendick&rft.au=M+Sackville&rft.au=S+Tang&rft.au=C+J+Brauner&rft.date=2011-02-28&rft.issn=0706-652X&rft.volume=68&rft.issue=2&rft.spage=241&rft.externalDBID=CJFS&rft.externalDocID=2286046451

4) Lastly.. once again you guys are on the topic of being fed antibiotics and pesticides. First of all, they are not fed pesticides, besides SLICE, which is not even needed, it is used as a precautionary method to stop sea lice from spreading to wild salmon during migration. This doesn't pollute the water, it goes directly into the salmon's skin to deter sea lice from attachment. The part about antibiotics, if you read the quote from me above... The average amount of anti-biotic's administered per 1 metric tonne is just over 500g... and only 10% of that is actually administered to net pens, the rest is administered to brood at contained sites.

5) Last thing.. Believe me when I say that fish waste does not pile up below farms. They select sites based on high current velocities so that waste, blooms, etc do not have a large effect on their fish. These sites must also have very high flow rates to provide oxygen to the high biomass. As said above, one of the reasons they place sites on high current sites is to flush waste. There may be minimal piling up of waste, but it is no where near what many activists make it out to be. And don't give me the sludge argument... what do you expect to find at the bottom of the aphotic zone of the ocean.... I would gladly take a look at a bottom sample you provide from 100 km's away from any location at the same depth, bet the sample will be the same.
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Bassonator

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Re: Another day another virus scare.
« Reply #11 on: April 20, 2012, 06:22:42 PM »

Just caught the evening news and I see that the witch of the west has Routledge doing her dirty work... :D
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Sandman

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Re: Another day another virus scare.
« Reply #12 on: April 22, 2012, 09:30:25 AM »

Sorry, if I "irked" you.

...Sources for this information? I read that whole paper and saw 2 papers quoted... would you consider that reliable? I can just as easily sit behind my keyboard right now and type a paper that long with my own points on how theoretical modelling proves that salmon farms don't have an impact on wild fish and that sea lice are not an issue. Just because a paper is published in a journal doesn't mean it is a good one...

The "paper" was a summary of the conference, not a "scientific study" in and of itself.  The symposium itself was the main source, and the three papers cited were merely referencing the previous conferences mentioned in the summary.

My whole point of citing that paper was to show that these symposiums are being held and discussions are taking place because there has been an impact in Norway (as emerged from the various discussions at the symposium).

I am afraid I was not able to read the paper you provided, as I do not have access to that database.  Was this study looking at "normal" infection levels, or the elevated levels found near farm sites?



Lastly.. once again you guys are on the topic of being fed antibiotics and pesticides. First of all, they are not fed pesticides, besides SLICE, which is not even needed, it is used as a precautionary method to stop sea lice from spreading to wild salmon during migration. This doesn't pollute the water, it goes directly into the salmon's skin to deter sea lice from attachment. The part about antibiotics, if you read the quote from me above... The average amount of anti-biotic's administered per 1 metric tonne is just over 500g... and only 10% of that is actually administered to net pens, the rest is administered to brood at contained sites.


However, small the amount, it is greater than the amount of pesticides and antibiotics fed to wild salmon.  You had asked what the difference was...I was just pointing out the obvious.

... Last thing.. Believe me when I say that fish waste does not pile up below farms. They select sites based on high current velocities so that waste, blooms, etc do not have a large effect on their fish. These sites must also have very high flow rates to provide oxygen to the high biomass. As said above, one of the reasons they place sites on high current sites is to flush waste. There may be minimal piling up of waste, but it is no where near what many activists make it out to be. And don't give me the sludge argument... what do you expect to find at the bottom of the aphotic zone of the ocean.... I would gladly take a look at a bottom sample you provide from 100 km's away from any location at the same depth, bet the sample will be the same.

At least you are candid in saying that the sites are chosen to protect the stocks within the pens (not the surrounding environment), any benefit to the sea floor from the natural "flushing" of the site is a happy coincidence.  I too would like to see a study done of the sea floor down stream of a net pen compared to the sea floor isolated from net pens (is there such a location in BC?).  I would bet they would not be the same (although they may both be smelly sludge).
« Last Edit: April 22, 2012, 11:01:22 AM by Sandman »
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absolon

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Re: Another day another virus scare.
« Reply #13 on: April 22, 2012, 10:43:37 AM »


At least you are candid in saying that the sites are chosen to protect the stocks within the pens (not the surrounding environment), any benefit to the sea floor from the natural "flushing" of the site is a happy coincidence.  I too would like to see a study done of the sea floor down stream of a net pen compared to the sea floor isolated from net pens (is there such a location in BC?).  I would bet they would not be the same (although they may both be smelly sludge).

Couple of points:

The flushing of the sea bed is not a "happy coincidence". It is one of the criteria for selecting a good site. The farms no more want a buildup of sludge under their sites breaking down and degrading the water quality than anyone else. They have money at stake in keeping the bottom healthy.

With all the farms in BC occupying an aggregate area about the size of Stanley Park, one would have to be rather incompetent not to find an area of seabed isolated from the seafarm's effects in the thousands of square kilometers of BC coastal waters.

Any deposition in the area of farms would be different than you would find in, say, major harbours, coastal industrial use areas, log booming grounds and other such areas impacted by human activity. The difference would be that in the area of farms, the deposition is organic material that decomposes to it's constituent elements and re-enters the system at the bottom of the food chain as nutrients. In other areas affected by human, commercial or industrial activities, the deposition will have a much higher level of long lived, often toxic materials that don't breakdown and support the trophic web in doing so. We have discussed this specific point previously and I referred you to Weston's study dealing with deposition under salmon farms. In the years since that study, deposition has become even less of an issue since farm practices have improved as a result of the attention paid by the industry to the issue.
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Sandman

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Re: Another day another virus scare.
« Reply #14 on: April 22, 2012, 12:31:30 PM »

The flushing of the sea bed is not a "happy coincidence". It is one of the criteria for selecting a good site. The farms no more want a buildup of sludge under their sites breaking down and degrading the water quality than anyone else. They have money at stake in keeping the bottom healthy.

Exactly.  I said the benefit to the environment (from them choosing that site for their farm) was the coincidence, the choice was made for the benefit of their stocks, not the environment.

Any deposition in the area of farms would be different than you would find in, say, major harbours, coastal industrial use areas, log booming grounds and other such areas impacted by human activity.

Thanks for making that comparison.  While I understand that other human activities have a damaging impact on the environment, that is hardly an argument for continuing another activity that might have less of a negative impact.  Once again, your repeated reference to the area affected being the size of Stanley park assumes a number of things: 1) the current number of fish farms is not going to increase. 2) the area of Stanley Park is small compared to the total coast line of comparable sea bed on the South Coast (for example, the area of Stanley Park may be small in comparison to the area of forested land in BC, but it is more significant in the area of Urban Forests in the Lower mainland), 3) nature can afford to lose the biodiversity in this "small" area.

The difference would be that in the area of farms, the deposition is organic material that decomposes to it's constituent elements and re-enters the system at the bottom of the food chain as nutrients. In other areas affected by human, commercial or industrial activities, the deposition will have a much higher level of long lived, often toxic materials that don't breakdown and support the trophic web in doing so. We have discussed this specific point previously and I referred you to Weston's study dealing with deposition under salmon farms. In the years since that study, deposition has become even less of an issue since farm practices have improved as a result of the attention paid by the industry to the issue.

And again, I do appreciate the efforts the farm industry has made to reduce their impacts, although I still think this has been done out of their own self interest in their stocks, not the environment itself. 

While deposition at farm sites may have become "less of an issue" since Weston's study, very little is still known about the secondary impacts of nutrient loading. While calculating the rate at which nutrients are released into the water column and determining the change in nutrient levels may be easy, this is a primary effect, and nutrient levels in themselves are not as important as the result of this nutrification and whether it leads to enhanced primary productivity such as harmful algal blooms.  Furthermore, although calculating the benthic deposition rate of carbon may be easy, it is "much more difficult to determine the rate at which this carbon can be assimilated, and to predict whether there will be deleterious changes in the benthic community." (Silvert, "Impacts of Marine Aquaculture" cited in Dr. Michael Tlusty et al. "Marine Aquaculture and the Environment" 2001).  Silvert also mentions that "although the immediate effects in the 'footprint' of the farm may be easy to monitor, transport process may move the depositional material to a relatively remote location. It is possible for an inlet to contain several farms, under all of which a healthy benthic community can be found, but at the same time for a seriously impacted area to develop at some distance from the farms due to mechanisms which focus the depositional material in that region." (Silvert 2001)  Since this affected site would be "some distance" from the farms, I am quite certain the farmers could care less about it, and would do nothing to correct this impact if not compelled to do so by the "antis."

I would like to add that I found this document (http://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&ved=0CDoQFjAC&url=http%3A%2F%2Fwww.neaq.org%2Fconservation_and_research%2Fprojects%2Fpublications_and_presentations%2Fpdf%2F12__.pdf&ei=90uUT4XfFKThiALy0PQb&usg=AFQjCNHQzyWp3uyH2cAJK_Mc6c3k8IS8Rw&sig2=XEGj0xDba5UZ74jn9SwYZg) very informative and it contains many references that support what absolon et al. have argued all along (that the expansion of marine aquaculture is inevitable and necessary, and that environmental impacts need to be managed so it can continue and grow.  I recommend it for everyone to read.  (Many of the articles have long citation lists for ED to peruse too).
« Last Edit: April 22, 2012, 01:01:22 PM by Sandman »
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