fish farm siting criteria & politics

Discussion in 'Conservation, Fishery Politics and Management.' started by agentaqua, Mar 17, 2008.

  1. chris73

    chris73 Well-Known Member

    Good for you and our salmon that you and many others have realized the risk and now live up to our responsibility to put an end to this ruthless business and thereafter to all those unnecessary threats to our salmon.

    Sockeyefry, here (finaddict) is your first hand and living proof that this business is filthy. First degree witness - is a smoking gun and would stand in any trial. But that's not even needed - common sense is enough to reveal the sad nature of open pen fish farm business. There are probably still supporters of the disk-shape earth theory out there and you perfectly fit this category. Some people live their denial; but there's no real sense in debating with them other than the amusement factor if the story wasn't so sad. But you can't bring anything new and interesting anyway...
  2. tubber

    tubber Well-Known Member

    “The decline of wild salmon populations have nothing to do with salmon farms.....Wake up and realise that you have been duped by the anti farm lobby before it is too late." sockeyefry

    Sf, Too late for what???? The more you write the more obvious it becomes that your intellect and knowledge have been displayed in their entirety and now you are trying to rise above the level of your incompetence, a feat we all know cannot be achieved. Admittedly, your early comments in the thread may have added to the base of knowledge on the topic for some of us. Lately, your posts strike me as the childish drivel of someone so indoctrinated by the industry and blinded by the need to make a living that his/her common sense, logic, and sadly, interest in and compassion for the renewed health and slendour of our coast have been diminished beyond repair.

    I am interested in your response, as predictable as it may be, to the story of my out-of-work seine boat buddies that delivered a load of farmed Atlantics in order to pay a few bills. They told me of a thick, writhing mass of "parasitic worms" at the bottom of each net pen. More striking were tales of the 5 gallon buckets of disinfectant and gas masks they were given to scrub the fish holds at the end of trip.
    Most alarming of all was how, when they were ready to brail out the fish, they had to pump the refridgerated sea water from the tank holding the fish into other empty ones rather than over board as they would normally do with wild fish. They were instructed to pump out the holds at least 20 miles off shore as the health of the harbour may be compromised by the water that the fish had been swimming in for less than a day. What would be the makeup of this chemical and parasitic cocktail?
    Of course, these guys being seiners, a term not quite synonomous with granola lover, pumped out just outside the harbour and headed home.
    This is a true story.
    I am not an environmentalist or a lobbyist, just someone that enjoys sportfishing and thinks the decline of our wild stocks is multi-faceted, yet reparable by changing the ways we manage our loggers, fishers of all types, farmers, and fish-farmers.
  3. finaddict

    finaddict Well-Known Member

    For the record< I worked for a company called Quadra Seafarms for 2 years as the operations manager. Was involved in the building of 6 farms and two hatcheries. Also managed a farm site for Hagensborg resources in Clayquot sound and worked on B.C. Packers sites in Sechelt during Vibriosis outbreaks brailing out tons of dead and diseased fish. Was a part of many deliveries of smolts (Chinooks back then) to many customer farms. Went to BCSFA meetings and watched the in-fighting and jockeying for position amongst all of the owners, who would jockey for position at the expense of other farms.Anything to gain the largest footing in those "gold-rush" mentality days (this was when spring 6-9's were fetching $7.50/lb wholesale). Also witnessed many escapes from storm damaged pens, huge disease breakouts that resulted in the dumping of tons of morts right into the ocean and many other regulatory infractions. What was the official remarks from senior management? Shut the hell up or you're fired. time and time again. Like I said, i was a part of it and it is not something I am proud of, but I will also not allow some lobbyist to claim that fish farming has no effect on he wild populations. Complete and utter BS
  4. sven

    sven Member

    Didnt quadra see farms build there pens out of WOOD??????
  5. Nimo

    Nimo Member

    Like the rest of the industry, they probably started with straw and mud. It's time to move to brick and morter - ie land based or not at all, before this disaster goes any further.

    I agree with Tubber who "thinks the decline of our wild stocks is multi-faceted, yet reparable by changing the ways we manage our loggers, fishers of all types, farmers, and fish-farmers."

    The FFFF situation is known and real. We're starting with that which we know we can change.

    This is my opinion and I'll be voting.
  6. Little Hawk

    Little Hawk Active Member

    Howdy Finaddict,

    Thank you for sharing what you know and what you did with all of us.

    It speaks volumes about your character and courage.

    My hat is off to you.


    Terry Anderson

    Wild Salmon Alliance
  7. agentaqua

    agentaqua Well-Known Member

    finaddict, you were brave and honest enough to give us your experiences:
    I, too - would like to add my voice in acknowledging the effort it must have taken to live through these experiences, and not fall prey to the caviler corporate mindset (because you obviously had morals and a sense of personal responsibility), and then be brave enough to share your experiences and concerns with the rest of the general public - whom are similarly concerned.

    Your actions demonstrate to the rest of us (which hopefully includes pro-industry types) how to speak and act with integrity. As a contrast, it's also important to understand the corporate siege mentality demonstrated by sockeyefry.

    I agree with Nimo (thanks for the vote of confidence, as well, Nimo), as he states: "I think Sockeye fry is the best thing to happen to the anti-farm lobby so far". His input is invaluable.

    Having all these points about the negative effects of the open net-cage industry discussed openly and fully - gives everyone an understanding of the issues - and an understanding of the fish farm culture of denial.

    The unfortunate thing about this culture of denial is that it is now only working to reinforce stereotyping and defensive posturing within the fish farm community. The general public is often far better educated about the effects of the open net-cage culture than many workers within the industry.

    I have had many conversations with many fish farm workers, and very few of them have read the peer-reviewed science available on these topics, and fewer still have looked at the available data. It's frustrating.

    Yet, all of them appear well trained in the art of illusion through misdirection (i.e. the sticklebacks are the cause of sea lice, etc.) by their top-end managers, industry associations, some DFO people, some bought politicians, industry PR people and magazines. If all rational arguments fail - they then personally attack the messenger.

    It's unfortunate that tricks work best only if you want to believe (and no matter what the cost to the public and the public resources).

    We have to then patiently wait for many of the fish farm workers to
    let-go of the sinking lifeboat of denial and swim in unfamiliar waters to the rest of us on the shore cheering them on. It's even more frustrating that DFO was supposed to be the responsible skipper driving the lifeboat that then hit the rocks, but instead fell asleep at the wheel.

    This thread about corporate mindset brings-up a discussion about identifying patterns.

    Hunters and fishermen are most successful when they understand their prey, notice patterns, and act on them. Many of you here are undoubtedly familar with this example from the real world.

    Field biologists similarly notice patterns in the fisheries resource in the ocean, and some of them write about these patterns and describe them in a rigid, scientific manner and publish these findings in peer-reviewed journals.

    These descriptions of patterns (or models) are the ones that the open net-cage industry are currently trying to slander (i.e. misdirection again). Follow sockeyefry's postings for an example.

    This is after scientists prominent in their fields have reviewed and passed the scientific document as valid and legitimate in the peer-reviewed process - and have been accepted by the scientific community.

    Yet, no viable, alternative models are given - no proof shown that the fish farms are not having the impacts described. Not even after some 30 years of the development of the industry are there examples of open net-cage technology successfully co-existing with adjacent wild salmon stocks - ANYWHERES IN THE WORLD.

    So, to explain our current political situation, I gain turn to science - the field of psychology.

    Psychology is a field of science where trained scientists notice and describe patterns in human behaviour through the lens of the social interactions with society-at-large, and explained through the biology of the brain.

    One scientist, fellow named Hare - has done extensive research into the field of diagnostic criteria for the clinical label for the term "psychopath" (a mental disorder marked by affective, interpersonal, and behavioral abnormalities), and the Criteria for the associated Dissocial Personality Disorder. He came up with a checklist.

    That checklist for the clinical diagnosis for the dissocial personality disorder (as described by the World Health Organization at is:

    1. Callous unconcern for the feelings of others and lack of the capacity for empathy (i.e. reckless disregard for safety of self or others).
    2. Gross and persistent attitude of irresponsibility and disregard for social norms, rules, and obligations (i.e. failure to conform to lawful social norms with a lack of remorse, as indicated by being indifferent about having hurt, mistreated, or stolen from another)
    3. Incapacity to maintain enduring relationships.
    4. Very low tolerance to frustration and a low threshold for discharge of aggression, including violence.
    5. Incapacity to experience guilt and to profit from experience, particularly punishment.
    6. Marked proneness to blame others or to offer plausible rationalizations for the behavior bringing the subject into conflict. (i.e. deceitfulness).
    7. Persistent irritability.

    The Aggressive Narcissism Criteria is particularly relevant in this discussion:

    1. Glibness / superficial charm
    2. Grandiose sense of self-worth
    3. Pathological lying
    4. Conning / manipulative
    5. Lack of remorse or guilt
    6. Shallow affect
    7. Callous / lack of empathy
    8. Failure to accept responsibility for own actions
    9. Promiscuous sexual behavior

    An easy-to-understand (highly recommended) online description of CORPORATE PSYCHOPATHY by Montague Ullman, M, D. can be found at:

    There have since been more mainstream analysis and descriptions of these findings that the general public may find more palatable to read or view. Recommendations include:

    1/ "Snakes in Suits" is a book released in 2006 by Dr. Paul Babiak and Dr. Robert D. Hare, available in the popular press. See:
    2/ The Corporation - a film by Mark Achbar, Jennifer Abbott & Joel Bakan - uses the checklist to identify and understand corporate behaviour across the Western World (esp. the US). see:
    3/ Thank you for Smoking is a 2006, Golden Globe Award-nominated film satire directed by Jason Reitman and produced by David O. Sacks. See:

    I think it is time to understand the very negative effects that the corporate mindset is having on our social structures and resource management, worldwide. We then need to reclaim our democracy and our human rights as stewards of spaceship Earth.
  8. sven

    sven Member


    You are part of the time and was part of the problem that gave fish farming this name, I would say things have definetly changed, A day doesnt go by when farmers have to sign there name 26 times, for every procedure someone does. Every farmer is personaly responsible for there actions.

    And if that is your attempt at "uncovering the horrible truth"

  9. agentaqua

    agentaqua Well-Known Member

    sven, you write:
    Don't confuse "personally responsible for their actions" with "acting responsibly". They are 2 very different things.

    Of course, all industry is ultimately "responsible" for their actions. The public and the public resource, however pay the costs for any industry that does not act responsibly.

    That fact that industry is ultimately "responsible" for their actions does not necessarily mean that they "act responsibility", though.

    Responsible corporate behaviour depends upon the thoroughness of current environmental legislation (and not voluntary industry "guidelines), and ultimately depends upon adequate enforcement, monitoring and consequences for the industry in question.

    An example from your industry: reporting escapees. Ever wonder why BC is reporting the lowest escapee rate in the world? Better-than-average fish husbandry you counter?

    Well reporting escapees is voluntary, and exceeding these "guidelines" can mean fines for that net-cage operation, but there is no third-party on-site monitoring and enforcement.

    Let me ask you this question: Did you ever speed in your life? Were you ever late for a meeting, and go a few miles over the speed limit, especially when you were in the middle of nowheres without any cops in sight? I think most of us all have.

    Now - show of hands everyone - who has then voluntarily checked themselves in at the local cop shop to get a $180 fine for speeding. Thought so. Point made.

    Another issue - even if an industry is caught ignoring guidelines, and is also then convicted and fined - are fines alone an effective deterrent - especially when the province often gives those fines straight back to the fish farming industry? See:
    page 6 at

    Even if the fines are not given back -are the fines costly enough for an industry to force them to change their practices? What if "doing it right" costs the industry more than the fines? Then the fines just become an operating expense.

    As far as the speeding analogy goes - I was still responsible for my actions, but it could be argued that I acted irresponsibly - because there was inadequate monitoring and enforcement. But nobody saw it, knew about, or were able to do anything about it. See the difference. here?

    So, adequate enforcement and monitoring along with suitable consequences - is key to making the claim for acting responsibly.

    Much of the commercial fishing industry has been forced to have on-board observers (at a cost of >$500/day), even on small owner-operator boats.

    Others have the observers as cameras that the footage is secured and played-back by third-party monitoring. All in the name of conservation and fisheries management.

    Yet, your industry does not have 3rd party on-site monitoring, and (it can be argued - and it has, with respect to monitoring, environmental reviews, sea lice levels - and other factors) very ineffective legislation and enforcement. All we have is your word.

    Believing somebody's word depends upon their credibility. Credibility depends upon past track records for telling the truth - which we all now know is terrible. So why should we believe you?

    DFO apparently does not think that believing a commercial fishermen's word is enough, either. So they legislate on-site observers.

    But still, you have no observers on your facilities - why not?
  10. finaddict

    finaddict Well-Known Member

    Sorry Sven but your "anti" paranoia is reading more into my statements than is actually there. I am well aware of the changes that have happened in fishfarming since I was involved. I was merely pointing out that I have some experience with that mindset of the fishfarmer and from everything I have seen from the BCSFA, nothing has changed in the mindset. I was actually still pro aquaculture for years even after I left it. My self justification was that it was the raw new beginning of an industry that needed to be able to go through some changes. Most of the damage being done by fishfarms is over stated. The damage done through sea lice transfer is not over stated and it is irrefutable.

    I have mentioned my experience in fishfarming merely to show that my claims come with some credibility. I have placed my cards on the table. Are you prepared to do the same, or will you be just like the other fish farmers and dig your head a little deeper into the sand also?
  11. chris73

    chris73 Well-Known Member

    Man, here is a new idea! DFO is actually in bed with BC Ferries. They seem to operate just the same way...:D
  12. finaddict

    finaddict Well-Known Member

    Whatsa matter Sven? Cat got yer tongue? Its real easy to criticise as an anonymous poster.
  13. agentaqua

    agentaqua Well-Known Member

    Sea lice physics without the math
    (why sea-cage fish cause wild fish to decline)[1]

    Neil Frazer Department of Geology and Geophysics, School of Ocean and Earth Science and Technology, University of Hawaii at Manoa, Honolulu , HI 96822 .

    November 30, 2007

    An open cage net pen, often referred to as a sea cage, is an enclosure designed to prevent farmed fish from escaping, and to protect them from large predators, while allowing a free flow of water through the cage to carry away wastes. Sea-cage farmed fish thus share water with wild fish, enabling transmission of sea lice from wild to farm, and farm to wild. Here I use elementary physics to explain why sea-cage finfish aquaculture causes the abundance of sea lice on sympatric wild fish to increase, and why increased sea lice abundance on wild fish causes their numbers to decline. Physics is important for this question because in observational data the year-on-year increase in lice and decline of wild fish can be difficult to distinguish from natural variability, which has been a source of confusion in the literature of aquaculture and fisheries. To understand the physics of sea lice, mathematics is helpful but not essential. In this paper, I explain without mathematics the concept of equilibrium, the host density effect, the reservoir host effect and why epidemics of sea lice on farmed fish occur in some localities and not others. Physics dictates that damage to wild fish can be partly, but not wholly, reduced by locating sea cages far from wild fish, by short grow-out times for farmed fish, by medicating farmed fish, and—most important—by keeping farm stocking levels below the level likely to precipitate epidemics of lice on farm fish.

    1. Introduction
    Sea cages have an undeniable appeal to people who worry that wild fish are being over-harvested, to businessmen seeking to make a profit, and to governments who wish to make nutritious sea food available to all. Unfortunately, there is now an overwhelming amount of data showing that wild fish usually decline—sometimes to near zero levels—in areas where sea cages have been allowed to proliferate. Often the decline is associated with a parasite that the wild fish and farm fish have in common. For example, in Scotland , Norway and Western Ireland stocks of wild salmon and sea trout have declined in areas with sea-cages containing farmed salmon.

    Often the data regarding declines are difficult to interpret: In some areas, wild fish decline immediately after sea cages are introduced; in other areas, wild fish do not decline until years after sea cage farming has begun; some stocks of wild fish decline to near extinction while other stocks remain at pre-farm levels. These sources of confusion are compounded by obvious difficulties in counting wild fish, and by the tendency of stocks of wild fish to fluctuate due to unknown environmental factors.

    In this situation, it is necessary to use basic principles of physics to try to understand the interactions between wild fish and sea-cage farmed fish. These principles can’t predict exactly what will happen in any given situation—there are too many unknowns for that—but they can tell us how to bet. My goal in this brief essay is to introduce some of those principles and apply them to the exchange of sea lice between wild and farmed fish.

    Scientists have found that understanding and communicating ideas about animal populations is much easier with the aid of arcana such as flow diagrams and differential equations. However, the most important parts can be communicated without mathematics, except for a very small amount of arithmetic, and I will try to do that here.

    2. Predators large and small
    Let’s take salmon as an example. Salmon in the wild are subject to predation by a multitude of micro-predators (e.g., bacteria, viruses, parasites) and a few large predators (macro-predators) such as sharks, seals, sea lions and orcas. A predator that prevents prey populations from increasing indefinitely is said to regulate the prey. It is easy to see how this works: if there are many salmon, mother seals find salmon easier to catch, and so young seals have an increased chance of survival, and next year there are more seals searching for salmon. Micro-predators also proliferate when prey are plentiful, and for similar reasons: it’s much easier to make a living and reproduce when prey are plentiful.

    When an animal is preyed on by micro-predators it is referred to as a host rather than a prey. Thus, biologists talk about host-parasite systems and predator-prey systems. This nomenclature reminds us that in the first case the predator is very tiny and seldom kills its prey immediately, whereas in the second case the predator is comparable in size to the prey and usually kills the prey during capture.

    In all systems that have been studied, it has been found that large predators are good at detecting weakness in their prey. Diseased fish tend to be slower and weaker than healthy fish, and their schoolmates tend to shun them to the edge of the school. Accordingly, diseased fish are easier for large predators to capture. Capture of diseased fish by large predators has a regulatory effect on micro-predators because the micro-predators present on or in the prey get eaten right along with the prey, or if they escape that fate, they may die without finding another host. The only exceptions to this rule are parasites with life-cycles requiring multiple hosts; for them, being eaten is part of the plan. Sea lice are not in this category since they require only one host fish to complete their life-cycle.

    One of the important things about a sea cage is that it excludes large predators but not micro-predators. Water flows freely through the mesh of the cage, carrying micro-predators in and out. Moreover, a sea cage confines the prey (farmed fish) at densities higher than those of wild fish. The regulatory effect of large predators on micro-predators is thus completely prevented by a sea cage, and it is not surprising to learn that disease is one of the greatest problems in sea cage aquaculture. In sea cage-farmed Atlantic salmon, for example, there are now well over 200 known infections, most of which are infrequent or rare in wild Atlantic salmon. In one recent year, salmon sea-cage operators had sea-lice related costs exceeding twenty percent of revenues.

    3. Sea lice
    Sea lice are parasitic copepods (tiny crabs) that graze on the surface of fish. They consume the mucus layer of the skin, the skin itself, and the tissues beneath the skin. External layers of mucus and skin are very important to a fish, not only as barriers to infection, but also as part of the mechanism (called an osmoregulatory system) that a fish needs to maintain the concentration of salts in its body at an optimal level. When salmon begin their life cycle in fresh water, their skin works to prevent fresh water from entering tissues, and after they enter the ocean it works to prevent fresh water from leaving tissues. Punctures and lesions created by feeding sea lice compromise this system and lower the fitness of the host. Wounds created by sea lice require metabolic energy from the host in order to heal. More important, wounds provide a pathway into the host for bacteria and viruses in the surrounding water. When newly infected with sea lice larvae, juvenile salmon roll and flash, increasing their visibility to predators.

    Biologists who study the population dynamics of parasites find it useful to distinguish two types of parasite: microparasites (including bacteria and viruses), which reproduce within the host fish, and macroparasites (including sea lice), which broadcast their offspring into the environment to find their own host or die. Most sea lice have roughly similar life-cycles, but to be specific I’ll use the salmon louse Lepeophtheirus salmonis as an example. Leps, as they are often called by researchers, have a life cycle with eleven stages. Adult lice meet and mate on the host, and the female louse then generates a clutch of 200-800 eggs in paired strings. The eggs hatch into the water as larvae, called nauplii, which do not feed and are incapable of swimming or attaching to a host. After drifting around in the ocean for three to four days the nauplii transform into copepodids which also do not feed, but can propel themselves toward a close-passing host and attach to it. If a copepodid does not find a host within about five days, it dies. After capturing a host, the copepodid transforms into a chalimus stage, attached to the host by a small filament, around which it grazes. Eventually the chalimus stage transforms to the pre-adult stage, which can move around on the host to feed, and then to the adult stage in which it mates. Male lice leave females after mating, to seek other females, and females produce several clutches of eggs during their adult life. The complete life cycle takes about two months depending on factors such as temperature and salinity. Under optimal conditions the life-cycle can be as short as a month, while under extreme conditions it can stretch to four months. Leps can survive for a while on hosts other than salmon, but can reproduce only on salmon and closely related species, collectively known as salmonids. Leps and other sea lice cannot survive in fresh water for more than a few weeks.

    The key to sea lice physics is to focus on larvae. A female sea louse that completes her life cycle produces about a thousand larvae. Assuming equal numbers of males and females, only two of those thousand larvae must complete their life cycle in order to maintain the population. Animals that generate many offspring, of which only a few survive, are known in biology as reproductive-strategists, or simply R-strategists, and sea lice are an example. Sea lice researchers estimate that less than half of sea lice larvae survive to the copepodid stage (infective stage), and that most of those copepodids die before capturing a host. To simplify the arithmetic let’s assume that each larva that captures a host has a one fifth chance of completing the remainder of its life cycle, and that there are an equal number of males and females. Then only one in a hundred larvae must capture a host in order to maintain the sea lice population. To see that this makes sense, notice that (1/5)(1/100)=1/500, which is the chance each larva must have if two of the thousand original larvae are to complete their life cycles.

    If you had trouble with that last paragraph, don’t worry. All scientific writing contains bits that require thought, and perhaps re-reading on another day, which is why most scientists read with pencil in hand. In science, that is what you pay to play, and even having a PhD doesn’t get you a discount.

    Let’s summarize the important facts about sea lice:
    1. Sea lice steal metabolic resources from the host, damage the host’s osmoregulatory system, provide a pathway for secondary infections, and increase the host’s risk of being eaten by large predators.
    2. A mature female sea louse produces about a thousand larvae.
    3. Sea lice larvae drift in the currents and cannot swim.

    Now let’s summarize the implications: From (1) it follows that sea lice increase, however slightly, the death risk (mortality rate) of their host. From (2) it follows that only two larvae out of every thousand must complete their life cycle in order to maintain the lice population. From (2) and (3) it follows that capture of a host by a larva is largely a matter of luck (randomness).

    4. The host density effect
    Suppose that the room in which you are reading this is a volume of ocean containing wild fish, but no farmed fish, and that you are a sea louse larva drifting about in it. This volume of ocean is closed, in the sense that you are unlikely to be carried outside of it by currents, which is why it does no harm to think of it as a room. The fact that the room in which you are reading is very different in shape from a volume of ocean defined by currents and probabilities doesn’t matter; all that matters is that you, the larva, will not be leaving it. Depending on the currents that carry you around the room, and the habits of the fish, you are more or less likely to have a fish pass near enough for you to capture it. If the fish all stay at one end of the room and the currents keep you at the other end of the room, your chances of capture will be poor. On the other hand, if the fish swim all through the room and the currents carry you all through the room, your chances of capturing a fish will be better. The important thing is that, in either of those scenarios, your chances of capture go up if there are more fish, and down if there are fewer fish. In other words, no matter what the environmental variables might be, your chance of capturing a fish is roughly proportional to the number of fish. This is called the host density effect.

    Continue to imagine yourself drifting around the room, hoping to find a host. Many other larvae are drifting too, with the same chance of survival as yours. After about five days your food stores will be exhausted. If the fish are so few that your chances of capturing one before you die are less than one percent, then the next generation of larvae is going to be smaller than your generation. On the other hand, if the fish are so numerous that your chances of capturing one are greater than one percent, the next generation of larvae will be larger than yours. You can see that for a small number of fish, sea lice will gradually die out, whereas for a large number of fish, sea lice will increase without bound.

    Wait a minute, you might say. Sea lice have been in existence for a very long time without dying out, or filling up the ocean. What is going on to prevent either of those things from happening? The answer lies in the regulatory effect of sea lice under natural conditions. Recall that sea lice injure their hosts, and that although the injury is usually not great, it does reduce the chance that a wild fish will survive. If sea lice become very numerous, wild fish suffer higher mortality rates and their numbers decline; conversely, if sea lice become scarce, wild fish enjoy lower mortality rates and their numbers increase. Population levels of lice and fish fluctuate, but neither one of them grows without bound. In biology as in physics this situation leads to the concept known as equilibrium. Natural systems are never quite at equilibrium because of the time lag between input and response variables. However, it is still very helpful to remember that there is an equilibrium, and that if you have to bet on where the system is headed, it is much safer to bet that it is headed toward equilibrium rather than away from it.

    5. Sea lice epidemics on sea-cage farmed fish
    Once more, imagine that you are a larva and that the room in which you are reading this essay is the volume of ocean to which currents and other variables confine you. Now suppose that there are no wild fish in your room, only farmed fish in cages at the other end of the room. If currents carry you into one of the sea cages, you are likely to capture a farm fish, but if not, you are certain to die.

    Suppose there are just a few sea cages with not many fish in them, so the chance of your capturing a host is just half a percent instead of the one percent needed to maintain your population. Then every generation of larvae will be half as large as the last. As a generation requires about two months, sea lice go through about six generations in a year. After a year, the number of larvae will have declined to (1/2)(1/2)(1/2)(1/2)(1/2)(1/2)=1/128 of its original level. This is known as an exponential decline. “Exponential” is now popularly used to mean a rapid increase of some quantity, but in this essay I use the word in its exact technical sense.

    Now suppose there are many sea cages, with many farmed fish in them, so the chance of your capturing a farm fish is two percent—twice as great as the one percent needed to maintain your numbers at their present level. After a year, the number of larvae will have increased to (2)(2)(2)(2)(2)(2)=128 times its original level—a phenomenon known as exponential growth. Large predators cannot get into the sea cages to eat infected farmed fish, and farmed fish are fed every day, even if they are weak and slow, so farmed fish numbers are not regulated by lice.

    You can see that sea cages and lice by themselves are an unstable system. If the number of farmed fish is greater than a certain level (the critical level), sea lice increase exponentially, but if the number of farmed fish is less than the critical level, sea lice decline exponentially. Unfortunately, the critical level depends on currents and temperature and harvest rates and treatment rates (the frequency at which farmers medicate their fish for lice), and many other variables that are impossible to calculate. The only way to tell that the critical level has been reached is that there is an epidemic of sea lice on farmed fish.

    One thing that can be said about the critical stocking level of farmed fish is that it often moves in the opposite direction to water temperature and salinity. Sea lice thrive only within a definite range of temperatures and salinities. If temperature and salinity are outside those optimal ranges, sea lice do not reproduce as rapidly. What often happens in real-world sea-cage systems is that the stocking level of farm fish is sub-critical; then temperature or salinity suddenly increases into the optimal range, causing the critical level to drop below the actual stocking level, and so a sea lice epidemic breaks out. Fish farmers understand this effect, qualitatively. What has not been appreciated is that the suddenness and severity of epidemics is explained by the exponential nature of the growth whenever the critical level is exceeded.

    6. Wild fish and sea-cage farmed fish together
    We saw above that in a model system consisting of wild fish and sea lice there is always an equilibrium to which the system tends to return when it is perturbed. In the real world, this equilibrium is a moving target because of exogenous variables such as climate, so the populations of fish and lice are constantly changing, trying to catch up with their changing equilibrium values. In order to understand the interaction of wild fish and farmed fish, we will assume that those exogenous variables are constant, and continue with the room analogy. As noted above, the room analogy can’t predict what will happen in every real-world situation, but it can tell us how to bet, which is sometimes enough to save us from disaster.

    Imagine again that the room in which you are reading this is a volume of ocean containing wild fish, sea lice, and some seals that like to eat fish. Imagine that things are pretty much in equilibrium, which means that each larva drifting in the water has a one percent chance of capturing a fish. There is a lot of randomness because of the currents and the variable paths of the fish, so occasionally a lot of larvae get lucky at the same time, and lice numbers increase. Then the seals find those infected fish easier to catch, and so the number of fish declines. Then the larvae have correspondingly less luck finding a host, and so lice numbers decline toward their original level where each larva again has a one percent chance of finding a host. Although these fluctuations are interesting, we can ignore them because our goal is only to track the equilibrium point.

    Now let’s put a sea cage at one end of the room, and put a few farm fish into it. The currents carrying larvae flow right through the mesh of the cage, so each larva in the room now has a better chance of finding a host (host density effect), and lice numbers rise. The farmed fish are protected from the seals by their cage, so their number stays the same, even though they have more lice on them. The wild fish aren’t so lucky. With more lice on the wild fish, the seals find them easier to catch, so wild fish decrease in number. How far do they decline? Remember that the equilibrium point is the point at which each larva has a one percent chance of capturing a fish; therefore the wild fish will decline until that is again the case. If the circulation in the room is such that the larvae have equal exposure to farm fish and wild fish, then the wild fish will decline by an amount equal to the number of farm fish.

    To understand the increase in lice and decline of wild fish, it’s important to recall that each larva has only a one percent chance of capturing a wild fish. Ninety-nine percent of the larvae would die without ever capturing a host if the farm fish weren’t present. This large number of surplus larvae means that the probability of capture is proportional to the total number of fish present. If we double the number of fish by adding as many farm fish as there are wild fish, then, to a very good approximation, the number of larvae that capture a host will double. In other words, to a very good approximation, the number of larvae that capture farm fish is not subtracted from the number of larvae that capture wild fish. Put another way, the lice on farm fish are surplus lice, and the larvae they produce are surplus larvae.

    So far, we have assumed that farm fish and wild fish have equal chances of being captured by a larva. What if the currents in the room are such that the wild fish and the larvae from their lice are mainly confined to one end of the room, and that the sea cage is at the other end of the room. In that case, the sea cage fish don’t increase a larva’s chance of finding a host by much, so larvae numbers rise only slightly and wild fish numbers fall only slightly.

    What effect does farm harvest rate have on the situation? If we harvest the farm fish and replace them with young fish at about the same rate that the wild fish die and are replaced, then from a larva’s point of view a farm fish is much like a wild fish. However, if we leave the farm fish in the cage for only a fraction of a wild fish life-cycle, then the larva that capture those farm fish won’t have as much time to reproduce, so lice levels won’t rise quite as much and wild fish won’t decline quite as much. Fish farmers refer to the time that their fish are in the cage as the grow-out time. Short grow-out times of farm fish are therefore good for wild fish.

    Up to this point the imaginary sea cage at the far end of the room has held only a few farm fish. What if we fill it with farm fish, or add another sea cage beside it, and fill both of them? Recall from above that there is a critical stocking level of farm fish. Below that critical level, if wild fish are not around to re-infect them, lice on the farm fish will decline exponentially to zero. However, above the critical stocking level, lice on the farm fish will increase exponentially. You can see that if the stocking level of farm fish is above the critical level there is no equilibrium point for wild fish. Lice just keep increasing, and wild fish keep declining, until the wild fish go extinct. That last wild fish, covered with sea lice, is easily caught by the seals. For the seals in our imaginary room, it is feast followed by starvation. Of course, in real situations farmers do not allow the lice levels on their fish to grow without bound, so wild fish may or may not go extinct; it depends on how many farm fish are present. If enough farm fish are present, then even very low levels of lice on farm fish can be enough to extinguish wild fish.

    7. The reservoir host effect
    To understand the reservoir host effect, it will be helpful to first consider the case where no sea cages are present, but this time with a slightly more complex room model. Where before we imagined one room with wild fish and sea lice, now we imagine two rooms connected by a hallway, with little movement of water between the rooms. Let’s call them room A (for adults) and room B (for birth). The wild fish spend most of their time in room A, but every autumn some of them migrate to room B for a brief period to mate and spawn, after which they return to room A. The fish eggs in room B take about six months to hatch, and after they hatch in the spring, the juvenile fish slowly migrate down the hall to room A to join the adults.

    Consider sea lice in the two-room model: As the adults in room A migrate down the hall to room B, their lice release larvae into the water, and soon room B has almost as many larvae as room A. When the adult fish have finished mating and laying their eggs in room B, they leave on their return migration to room A. With no hosts left in room B, the larvae left there die without finding a host. When the fish eggs in room B hatch, they enter an environment without sea lice larvae. This is fortunate for them, as the effects of sea lice on mortality are roughly proportional to body mass: a few lice on an adult fish increase the chance of death only very slightly, whereas the same number of lice on a tiny juvenile fish would make its death nearly certain.

    As they grow, the juvenile fish slowly migrate down the hall toward room A. About halfway down the hall—a year has now elapsed since the migration of their parents to room B—the juveniles migrating toward room A meet a cohort of adults migrating in the opposite direction. By this time, the juveniles are large enough that a few lice do not dramatically increase their mortality rates. In the life-cycle of the wild fish, room B functions as a refuge from sea lice for juveniles.

    Now suppose we put sea cages in room B. The farm fish in the cages initially have no lice. When the adult wild fish arrive there to mate and spawn, their lice are releasing larvae into the water, and those larvae infect the farmed fish. If farm stocking levels are sub-critical, the lice on the farmed fish decline over the next six months while wild fish are absent, and when the juvenile wild fish hatch there are some larvae in the water, but not many. However, if farm stocking levels are above the critical level, lice increase exponentially on the farm fish over the winter, and the juvenile wild fish emerge into water full of larvae. Their mortality rates will be very high. The sea cage fish in room B are said to function as a reservoir host for sea lice.

    The reservoir host effect is especially relevant to sea cages located on coasts with runs of wild salmon. When adult wild salmon migrate from the open ocean past the sea cages on their way to their natal rivers to spawn, larvae from the adult lice on the wild salmon infect the farmed fish in the cages. The farmed fish provide a reservoir host for lice over the winter while adult wild salmon are absent. In spring, the juvenile wild salmon must pass the sea cages on their out-migration to the open ocean, so they are infected by larvae from the lice on the sea-cage fish. Pink and chum salmon are particularly vulnerable in this regard because they enter salt water very soon after hatching, weighing a gram or less.

    8. Conclusions
    It is well known that in order to minimize lice transfer between farmed and wild fish one should keep them as far apart as possible for as much of the year as is possible, perhaps by locating sea cages in places wild fish seldom go. However, many people imagine that keeping lice levels on farm fish at or below those on wild fish (by chemical treatment, for example) is sufficient protection for sympatric wild fish. What they fail to note is that most of the larvae that capture farmed fish are larvae that would have died if the farmed fish were not present. This is a direct consequence of the randomness of larval capture and the large numbers of larvae produced by female sea lice. The lice on farmed fish thus generate extra larvae in the water, and higher levels of infection on sympatric wild fish.

    Using basic physics, we showed that a system of farmed fish and sea lice is unstable because it has no regulatory feed back other than what farmers choose to provide by more frequent treatment and shorter grow-out times, both of which require financial sacrifice. We saw that the instability of the farmed fish-sea lice system is manifested in a critical stocking level of farmed fish. Above the critical stocking level, lice increase exponentially, and below the critical level lice decline. The critical level depends on conditions such as ocean currents, that are poorly known, and conditions that can change rapidly, such as temperature and salinity. Thus, a fixed stocking level in a farm system can be sub-critical under some conditions and super-critical under others.

    As sea lice are harmful to fish, they must regulate fish populations, at least to some extent. Thus increased levels of sea lice cause wild fish to decline. As increased farm fish cause increased sea lice, it follows that increased farm fish cause wild fish to decline. At sub-critical stocking levels, mathematics are needed to estimate the magnitude of the decline. However, mathematics are not needed to understand that when a farm system is super-critical, sympatric wild fish decline toward extinction.

    Some of the material above is adapted from:
    Frazer, L.N. (2007), Comment on “Sea lice on adult Pacific salmon in the coastal waters of British Columbia , Canada ” by R.J. Beamish et al., Fisheries Research, 85, 328–331.

    [1] This essay may be freely copied.
  14. agentaqua

    agentaqua Well-Known Member

    Over the few years, DFO and fish farm proponents have tried to suggest that there are other "alternative" hosts for sea lice that may infect outmigrating juvenile salmon - rather than the more obvious established net-cage facilities - with their potential millions of hosts.

    They floated the idea that marine threespine sticklebacks (Gasterosteus aculeatus L), may be the “source” (verses a “sink”) of lice that could be the “smoking gun” affecting outmigrating juvenile salmon in the Broughton.

    What evidence do we have to assess this claim?

    To understand differences in lice loading, first we need to define some terms (from Margolis et al. 1982):
    1/ Prevalence, usually expressed as a percentage, is the number of individual hosts infected with lice – or the percentage of a population infected.
    2/ Intensity is the number of lice on each infected host, only.
    3/ Abundance is the total number of lice divided by the total number of hosts (infected and uninfected), or the average number of lice on each individual in any population.

    So how do the numbers compare? What data do we have for the suggested alternative – the DFO-suggested “potential source” of lice for outmigrating juvenile salmon?

    Let’s review Jones et al. (2006). They state that: “Over 97% of the 19,960 Lepeophtheirus specimens and nearly 96% of the 2,340 Caligus specimens were in the copepodid and chalimus developmental stages.” This means that only 3% of the total lice were motile (preadult and adult). If we assume a 50/50 sex ration, then only 1.5% or less of the lice were females (preadult, adult and gravid), and then some 1% or less were available to contribute to the background infection levels to outmigrating salmonids.

    1% or less??? That doesn’t sound like a high number. What percentage of lice are gravid (egg-bearing) in a population assumed to be a source of lice? What about wild sources?

    In Beamish et al. (2005), gravid female L. salmonis on trawl-caught wild salmon represented 33.3% of all mobile stages. Most gravid females were L. salmonis accounting for 14–37% of all stages and 22–38% of all mobile stages for each Pacific salmon in both areas combined. From 14 to 21.4% of the total lice load on returning adult pink salmon were gravid females; 4.3 to 21.7% for returning sockeye salmon, 13.7 to 22.2% on chums, 28.1 to 35.6% for Chinook, and from 28.8 to 35.5% for coho.

    The average intensity of L. salmonis on all species, in Beamish et al. (2005) both their study areas was 4.1 gravid female sea lice and 5.1 adult female sea lice. The mean intensity of sea lice on wild salmon was ~31.8 for all species combined. This means ~12.9% of the total ice loading on trawl-caught wild salmon in the Broughton by Beamish et al. (2005) were gravid.

    What about the farm fish? Beamish (2006) reported data is less clear with this answer (not sure why, Beamish et al. (2005) was very explicit with this question).

    Well - if you want to believe DFO - this is what they have been saying...

    When DFO officials appeared before the Parliamentary Fisheries Committee meeting on Tuesday, on April 20th 2004; Wendy Watson-Wright responded to Mr. Peter Stoffer’s questioning on sea lice and deleterious substances by stating that Yves Bastien, former Commissioner for Aquaculture Development told her that “maybe ten fish in that whole pen will have sea lice and the rest won't, so the deleterious substances are quite small in that regard”.

    If Yves Bastien was not lying and misleading government officials; this would mean that if only 10 fish in a pen of 530,000 aquacultured Atlantic salmon had lice, the prevalence would be 0.0019%.

    Prevalence (as we discussed), usually expressed as a percentage, is the number of individual hosts infected with lice. What are the common net-cage sea lice abundances that we can find?

    Stolt Sea Farms did post sea lice results on their web page for a short time:

    This link no longer works. However, the abundance (not prevalence) rates (or Ave. No. lice per host fish) off the web site was 3.32, with no data available to tell stages or fecundity (i.e. No of gravid females).

    As reported in Beamish et al. (2006), numbers of motile lice (Lepeophtheirus and Caligus spp. combined) of motile lice expressed as a percentage of total lice load on farmed fish in 2003 in the Broughton ranged from a low of in February of 36.2% to a high of 80.8% later in the season in August, with the average percentage of motile (adult and preadult) lice being 60%.

    If we assume a 50/50 sex ratio, this means that there is an average of ~30% of the total lice load consisting of mature and premature female lice. The numbers of gravid females would be expected to be somewhat lower than the total of all mature female lice, and may fluctuate with progression of infection dynamics within the cultured stock. However, a minimum of 15% would be expected, with a high of possibly 20+%. This 20+% compares well with the Beamish (2005) wild salmon trawl lice data.

    It looks like wild salmon have ~12.9% of their lice load as gravid females; farmed stocks have ~20% of their lice load as gravid females, while sticklebacks only have less than 1%.

    Which would be the valid scientific assumption on which are the most likely source, and the most likely a sink? If you were a credible professional entrusted with assessing risk to wild fish – what would you suggest?

    Kent (1994) has some suggestions: The risk of increased disease transfer to wild stocks depends on factors such as: survival of the pathogen in sea water (depends on elapsed time, water temperature and salinity), number of pathogens released from farm stock (depends on prevalence of the disease and absolute numbers of farmed fish and stocking densities, and water flow), the number of pathogens required to initiate infection (depends on species, and presence of open lesions), virulence of the pathogen (which can sometimes change or mutate), and route of transmission (including intermediate host presence and distance)(Kent 1994).

    We need to know absolute numbers of gravid female lice from any suggested lice source, obviously. Let’s look at absolute numbers of available hosts, and their gravid lice loads then.

    How many sticklebacks might there be in the Broughton, capable of infecting outmigrating juvenile salmon? We need to assess the habitat capability of the area.

    In Murphy et al. (2000), the average number of threespine sticklebacks captured each seine in eelgrass was 57.53 sticklebacks per tow in 1999 from 8 sites near Craig Alaska.

    In Johnson et al. (2003) the average number of sticklebacks caught per beach seine, using the same methodology as Murphy (2000), was 29.16 fish per tow for the years 1998 to 2000, from 30 sites in Alaska.

    The eelgrass beds in both Murphy et al. (2000) and Johnson et al. (2003) were sampled with a 37m long beach seine that was pulled around in a quarter –circle of 18m radius. This means that the stickleback densities were approximately 57.53 fish per 255m2 or 0.226 fish/m2 from Murphy et al. (2000), and 29.16 fish per 255m2 or 0.114 fish/m2 from Johnson et al. (2003).

    From Geostreams (2003) the average size of the eelgrass beds in BC is 2.2 Ha, or 22,000 m2. From, it can be seen that there are 22 eelgrass beds and 5 estuaries illustrated in the area of the Broughton.

    Using the higher 0.226 fish/m2 stickleback density from Murphy et al. (2000) - this means that we would expect a population of ~5000 sticklebacks in each average-sized eelgrass bed in the Broughton, and maybe an additional 5,000 sticklebacks in each of the larger estuaries.

    Since there are 22 eelgrass beds and 5 estuaries indicated on the SHIM site ( in the area of the Broughton, we would expect a rough ball-park estimate of the size of stickleback population in the Broughton to be some 135,000 fish in total that could potentially interact with outmigrating juvenile salmon.

    It is expected that there are more eelgrass beds in the Broughton than indicated on the SHIM site – however, a number of these identified sites would potentially also have minimal interactions with outmigrating juvenile salmon since some of them are protected way inside coves and saltwater estuaries – away from migratory routes and more exposed locations.

    The 135,000 stickleback population estimate should be seen as a conservative estimate, since we are also using the higher (i.e. 0.226 verses 0.114 fish/m2) stickleback density estimate from Murphy et al. (2000).

    How do numbers of farmed salmon compare?

    Orr (2007) recently examined this question. He examined 12 active farms within Marine Harvest 19 sites, and found that the numbers of farmed Atlantic salmon at these 12 farms varied between 1 and 5 million which over two years (2003 and 2004). 2003 was a fallow year. There are 28 farm sites within the Broughton.

    Stolt Sea Farms numbers from 2005 indicated an average number or 529,000 Atlantic salmon per net-cage site. If we assume 100% utilization rate of each site, the numbers of Atlantic salmon calculated to be in the Broughton in 2005 are 14.8 million fish. However, there are always some sites fallowed. An estimate of 10 million farmed salmon would therefore be a conservative estimate.

    These fish are resident year-round, with some turn-over of harvested/restocked sites within any particular year. For resident sticklebacks and farmed fish, the resident time is 365 days a year; but sometimes there are times that any 1 farmed site may be fallow due to a time lag between harvesting and restocking. Usually the growth cycle is some 18 months – so for all sites that report containing farm stock – the interval is 365 days a year.

    We need next to assess elapsed time of host parasite transfer. What about the wild salmon and residence times?

    Beamish (2005) also states that the numbers of wild fish migrating through the Broughton could represent a range from about 10 to 50 million fish. 20 million salmon would be an average estimation. No estimation of residence time was given by Beamish et al. (2005).

    However, a stay of 1-14 days could be suggested for migrating wild salmon stocks (dependent upon the size and location geographic boundaries inferred), with the exception of stocks of localized subadult winter spring salmon. Candy and Quinn (1999) give an average travel rate of 15.2 km per day for returning chinook into coastal areas as indicated through implanted sonic transmitters.

    The farther you are out into Queen Charlotte, Broughton and Johnston Straits (away from the smolt early marine rearing areas), the more likely you are interacting with more of that potential 20 million, although any site would still interact with only a small percentage of that total. The closer you are to the head of inlets (and to the areas where the small wild salmon smolts grow) that total potential number of interacting wild salmon would dwindle to thousands.

    Let’s artificially bump the potential numbers of interacting wild salmon to 20 million, then – to error on the side of the fish farmers. Let’s use something like 1 week as the length of time each individual wild salmon is in the area.

    Now that we know ball-park numbers of potential hosts, and resident times – we can estimate approximate percentages of potential host contribution to yearly lice loading.

    First we need to estimate how many eggs a gravid female louse can contribute over one year and in particular during the time that juvenile salmon are outmigrating.

    The average number of eggs per louse on Atlantic salmon is ~300 eggs per female (Johnson and Albright 1991). This number could vary with the host species; however it is a useful rough estimate.

    Next, how long do gravid lice survive?

    Pike and Wadsworth (1999) state that Adult sea lice have a life span on a host in seawater for 75 days at 9-10oC; or 191 days (~6 months) at 7.4oC. However, one study (Nordhagen et al., 2000) indicates that the life span of L. salmonis could be up to one year at lower water temperatures.

    We will assume that a gravid female louse will release 300 eggs over a 6 month period. We will also assume that the numbers of gravid female lice are constant over time for the purposes of apportioning host contribution to localized lice loading (although egg string development will probably increase over the summer period).

    Taking into consideration the best estimates available for the sizes of the potential host contributions and the numbers of gravid female lice on the host population – the approximate contributions of each host reservoir is given as follows:

    • Farm salmon and escaped farmed salmon combined: 86.3%
    • Wild salmon: 13.6%
    • Sticklebacks: 0.2%

    Why would anyone suggest sticklebacks are a “source” of lice? 0.2% is a very small contribution from sticklebacks. In fact, it is more likely that sticklebacks are a “sink” verses a “source” of lice.

    Also, the 13.6% contribution from wild salmon is based on the assumption that the wild stocks release their infective lice stages in the correct time to infect outmigrating juvenile salmon.

    Most stocks and species of wild salmon return much too late to infect outmigrating juvenile salmon, although some of the earliest returning adult salmon could infect the later outmigrating juvenile salmon. The 13.6% is therefore a very inflated figure.

    86.3% is however, NOT a conservative figure. That means that at least 90% of the infection in the Broughton is likely due to farmed fish industry and its current reliance upon open net-cage technology - and not alternative red-herrings like sticklebacks.

    Why hasn't DFO already done this kind of analysis? What is they have - but buried it?

    Canada and DFO supports the statement in Principle 15 of the “1992 Rio Declaration on Environment and Development” which states:
    “In order to protect the environment, the precautionary approach shall be widely applied by States according to their capability. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.”

    This “precautionary approach” should encourage, or perhaps even oblige, decision-makers to consider the potential for harmful effects of activities on the environment before (and not after) they approve those activities ( doc-e-allfonts.pdf).

    Why isn't DFO upholding Canada's international agreements? Isn’t it time we stopped pretending there is no problem, and address this one head-on?
  15. sockeyefry

    sockeyefry Guest

    Yep you were part of the problem, and it was your actions which created the black eye on salmon farming. and now you show up giving "evidence" for the antis. Give me a break.


    I case you didn't notice. Neil Fraser is a GEOLOGIST, which means his writing about farms is only his OPINION.

    Now Fish farmers are psychopaths? More deflection BS.

    Your most recent post is nothing more than a bunch of research on a topic, which you string together to make it seem like it is connected. You then state your opinion of what each Lice source could be and the % of each. Again more carefully contrived fantasy. ou still have not answered my original question. If the salmon enter the farms from freshwater hatchery and are lice free, where do they get the lice?

    You , and others on this forum (Nimo, Chris 73) call me and anyone else who dares to try and put forward a contrary position an industry no mind, etc..., yet you offer nothing in return except the same drivel of the anti's. The only reason you are not held up to ridicule here is that it is an anti forum.

    You oourse realise that you cannot prove a negative. That is you cannot prove something does not exist. You of course know this and is why you ask the farmers to prove that they do not have an effect. It is far easier to prove something does exist, and I am waiting for you to prove the impact on wild salmon beyond opinion and mathematics. As of yet you nor anyone else has done that.
  16. chris73

    chris73 Well-Known Member

    Pfff. What a useless post, sockeyefry. Sounds like a 3 year old: "No, no, no, mom! Just because I want so!"
  17. Dave H

    Dave H Well-Known Member

    "If the salmon enter the farms from freshwater hatchery and are lice free, where do they get the lice?"

    They "get the lice" from the lice that naturally live in our waters.

    Are you really that naive to not see the fact that lice already live here is the genesis of the problem?

    You cannot introduce 10,000,000 adult sized fish and have them live for a year or longer in any area of our coast and not expect the lice to find them.

    Take one step past the fact the lice were here first.

    It's not that hard.

    Well, I guess if your paycheque depends on not taking that step it IS pretty hard.

    Take care.
  18. OldBlackDog

    OldBlackDog Well-Known Member

    As you feel that you have the answers and the ear of the fish farmers, then it is a simple thing to resolve.

    Fallow "ALL" the farms out of the Broughton and lets see the results.
    Simple and easy.

    But that is not going to happen as the owners are not going to do this.

  19. sockeyefry

    sockeyefry Guest

    But Old Dog, you haven't proven that they are the cause. You would create an unnecessary burden on legitimate companies because you think something is so.

    Dave, Exactly correct, but if the lice from the Wild source infect the farm fish, are they not also the cause or contribution to the wild lice as well? So far you anti's conveniently like to gloss over this fact.

    Just what I would expect from you Chris, more name calling.
    Don't you think it is funny that a geologist is commenting on salmon? I would listen to Morton before him. How about responding to what I have posted, like Agent does.
  20. Nerka

    Nerka Member

    "but if the lice from the Wild source infect the farm fish, are they not also the cause or contribution to the wild lice as well? So far you anti's conveniently like to gloss over this fact."-sockeyefry

    It is the first few months of pink and chum marine residence that is of concern. No one is arguing that lice are not brought into the nearshore marine environment with returning adults, this is how sea lice are naturally transmitted from one generation to the next. But this occurs in mid to late summer (i.e. June-July-Aug) and is also when farmed fish would first become infected. It is the subsequent transmission of lice from farmed salmon to wild pinks and chums in the spring (i.e. April and May) when these fish are without scales and undergoing a major physiological transition (i.e. smoltification) that is of concern. There is no place else in the north Pacific where pink and chum fry are infected with lice in any appreciable amount (e.g. > 5%) prevalence) during this critical period, except for the Broughton.

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