Study: Sea lice killing off wild salmon

[lskiles]

I have never liked the taste of farmed fish. Too bland and I was told that when they escape, and some do, they will dilute the wild population. I do not know if that is true, but I just do not like the whole idea of fish farms.

This morning this news item came accross my screen to reinforce my prejudice. Sea-lice (I thought at first it was a joke somebody made up) are killing salmon.

Give this article a read...

http://news.yahoo.com/s/ap/20071214/ap_ ... lmon_farms

Lewis

[fisherhall]

I hope that the fish around here don't get infected. Interesting article.

[A9]

If you consider farmed fish also to be hatchery fish, then there are a ton of those kinds of fish out in the salt...Many rivers have hatcheries now and hatchery fish need to be bonked...

[Anglinarcher]

I have to be honest with all of you. Has it not been said that there is a sucker born every day?

First, I get a little nervous when Yahoo News has an "Environmental writer" and this becomes the source of such important information. Is it possible, yes! Are we getting all of the un-slanted news, doubtful! Now, if the writer was their "Scientific Writer", maybe I'd take the article with a bit less salt, but I need more information before I can get too concerned.

It should be noted that I have other concerns about some of the farms. Let's just say that pollution from wasted food and concentrated fecal matter concerns me a lot; these concerns have a lot more credible sources.

Sam Kafelafish, I've got to call you out on this one. Hatchery fish are spawned and initially raised in fresh water, where sea lice cannot live. They can not spread sea lice because the sea lice have died before the spawners are spawned out, and the smolts do not have sea lice.

Sam, you are entitled to your concerns about Hatchery fish, and a lot of people agree with you. Personally, I don't buy into the concerns. One thing is for sure, to follow your simple minded logic, all salmon should be "bonked", because the wild salmon have the same threat as hatchery strains do as far as sea lice are concerned.

Sorry Sam, I am entitled to my opinion too.

[lskiles]

First, I get a little nervous when Yahoo News has an "Environmental writer" and this becomes the source of such important information. Is it possible, yes! Are we getting all of the un-slanted news, doubtful! Now, if the writer was their "Scientific Writer", maybe I'd take the article with a bit less salt, but I need more information before I can get too concerned.

HEY, they would not put it on the internet if it was not true!! You got to know I am kidding, right.

I do believe there is a big difference all around between hatchery fish and farmed fish. The hatchery fish are usually released fairly small ~not all, but most~ and then eat real "fish food" out in the wild and grow strong and sure they are not like "wild" trout, but they are a far cry from farm fish.

Hey, I know...lets go catch some!

Lewis

[cavdad45]

I'm laughing too hard!!! Sea Lice killing salmon?!?! What a joke!

If sea lice bug you then only fish for salmon in freshwater. Most saltwater fish I've ever caught have some sort of parasites and they rarely cause harm. I agree, check out the source more.

Ever read the "Book of the Black Bass" by Dr. Herschel? He said that bass come out of the water at night and forage on the shore and on sandbars.

[Fisherman_max]

what the heck are you serious?

[Toni]

It isn't just Yahoo News and at the end it says a UW professor said the same thing. I made it red. I still don't understand at all how that could hurt wild salmon.


http://seattlepi.nwsource.com/local/343 ... mon14.html
Last updated December 13, 2007 9:32 p.m. PT

New evidence fish farms hurt wild salmon
Sea lice threaten to wipe out runs, researchers say

P-I STAFF AND NEWS SERVICES

Researchers have new evidence that as the density of salmon farms increases, they can drive nearby wild salmon runs to extinction.

The problem is sea lice, a natural parasite that normally attaches to adult salmon with little ill effect and has little contact with vulnerable juvenile salmon. All that changes, however, when fish farms move in.

A study in the journal Science on Friday shows that sea lice infestations around salmon farms in British Columbia's Broughton Archipelago have reached a density so high they could completely wipe out pink salmon in rivers where migration routes cross ocean-based farms. Fish numbers in those waters have already dropped by more than 80 percent.

"We've seen sea lice infestations on juvenile salmon in Norway, Ireland, Scotland and Canada, but it's been unclear and very contentious what the impact of the sea lice is on the wild salmon population," said Martin Krkosek, lead author of the study and a doctoral candidate at the Center for Mathematical Biology at the University of Alberta.

"What's really new and exciting about this paper is this is the first time scientists have had enough detailed data to actually measure the impact of sea lice on wild salmon populations."

In Washington there are Atlantic salmon pens near Anacortes, in Skagit Bay, near the south end of Bainbridge Island, and at Port Townsend.

For an unknown reason, sea lice numbers have stayed low in pens in Puget Sound, said Dan Swecker, state senator and a spokesman for the Washington Fish Growers Association, an industry group.

"We've never had a problem with it here," he said. "It's so few and far between we don't do anything. We ignore it here."

Swecker and others questioned whether it was fair to blame the fish deaths on sea lice.

"The sea lice infestations go up and down and so do survival of the salmon," said Walt Dickhoff, a division director for the Pacific Northwest Fisheries Science Center in Seattle, who read the study.

"There are so many factors in there, it's hard to say it's the sea lice," he said.

Principally funded by the Canadian Natural Sciences and Engineering Research Council, the peer-reviewed study is the latest in a series by scientists trying to push the Canadian government to place more strict regulations on salmon farms to control sea lice.

Based on government stream surveys, the study used a computer model to analyze pink salmon returns in 64 rivers without exposure to salmon farms and seven rivers where young fish must migrate past at least one salmon farm. The study considered returns before and after sea lice infestations were noticed in wild fish in 2001.

The Canadian Department of Fisheries and Oceans, which regulates salmon farms and is responsible for protecting wild salmon, said the study overstates the risks, which are not consistent with figures for pink salmon returns since 2002, when populations collapsed.

The authors suggested that the simple solution is to move fish farms out of salmon migration corridors. But that's unrealistic given the prevalence of wild salmon, said Brian Riddell, head of the salmon science branch of the department's Pacific Biological Station in Nanaimo, B.C.

Wild pink salmon are not a commercially important species, but they are an important food source for orcas and other salmon in the ocean.

They also provide food for bears and other wildlife and nutrients for trees.

The study suggested that the density of fish farms reached a tipping point in 2001 that triggered a killer sea lice infestation.

Ray Hilborn, a professor of fisheries at the University of Washington who was not associated with the study, said he replicated the analysis and agreed with the conclusions. But the data are "noisy," with a lot of variability, because stream surveys are far from exact, he said.
P-I reporter Lisa Stiffler contributed to this report from The Associated Press.

[A9]

Sam Kafelafish, I've got to call you out on this one. Hatchery fish are spawned and initially raised in fresh water, where sea lice cannot live. They can not spread sea lice because the sea lice have died before the spawners are spawned out, and the smolts do not have sea lice.

Sam, you are entitled to your concerns about Hatchery fish, and a lot of people agree with you. Personally, I don't buy into the concerns. One thing is for sure, to follow your simple minded logic, all salmon should be "bonked", because the wild salmon have the same threat as hatchery strains do as far as sea lice are concerned.

Sorry Sam, I am entitled to my opinion too.

I didn't read the article, and I'm fully aware that sea lice cannot live in freshwater...

No problem with your own opinion...Everyones got em and thats 100% cool...

What I meant about bonking hatchery fish had nothing to do with the sea lice issue. I guess I might have phrased it wrong for you? Sorry if that was the case...I meant that hatchery fish shouldn't be spreading their genes into the wild fish gene pool, by spawning with wild salmon, and thats more what I'm concerned about...Basically the dilution of wild salmon genes...

[tnj8222]

you guys are acting like this is joke but its a seriouse problem. yes the sea lice are killing JUVINILE salmon. check out ifish.net they alot more info on this

[cavdad45]

There are bigger fish to fry than worrying over sealice whose threat has no credibility. Control sea lions and tribal fishing if you really want to salvage our dwindling salmon stocks.

[A9]

cavdad,
add dams and human impacts on rivers and habitat to the list.... ahead of sealions and tribal fishing....

[Jake Dogfish]

Its clear than some did not read the article, and really don't understand what is going on here.
Sam had a great point. Hatchery salmon go out to sea, live there the vast majority of there lives there competing with wild fish. Although they might not be in as close of quarters, (net pen) they are spreading sea lice on to wild fish just like any other...

For some reason, there is always a "it won't happen here" attitude towards fishing. Then, it usually does and there is no foresight reaction...

[Jake Dogfish]

cavdad,
add dams and human impacts on rivers and habitat to the list.... ahead of sealions and tribal fishing....

Another informative post...:thumleft: Some live in denial...

[Fish Antics]

As I read through this thread I wish the conversation had occurred in 1950. If we had chosen to mitigate the impending devastating impacts of widespread habitat destruction (dams, logging, agriculture,urban development, pollution) and unrealistic levels of harvest (the so called, as it turns out, flawed management policy of "maximun sustained yield") perhaps we could sit and speculate about the advantages of "wild" salmon over "hatchery" salmon. But we didn't. And now we have inherited the reality that wild salmon populations are a fraction of their former numbers. It would be the greatest second blow to naturally producing salmon to advocate for the systematic closing of hatcheries. People condemn hatchery fish based on genetics arguments and competitive impacts to wild salmon juveniles. Both have merit. But we are well past the point of being able to sustain fishermen at the current harvest rate soley on the backs of wild fish. So I think it is better to be cautious about generalizing that we should shut down hatcheries as we seek solutions (and pay the price) to protect rebuilding stocks. In the meantime, freshwater and ocean rearing conditions, as well as viral and other disease threats are worth our attention. The role of ectoparasites, such as sea lice, enhanced by human farming, constitute yet another layer of complication.

[Anglinarcher]

As I read through this thread I wish the conversation had occurred in 1950. If we had chosen to mitigate the impending devastating impacts of widespread habitat destruction (dams, logging, agriculture,urban development, pollution) and unrealistic levels of harvest (the so called, as it turns out, flawed management policy of "maximun sustained yield") perhaps we could sit and speculate about the advantages of "wild" salmon over "hatchery" salmon. But we didn't. And now we have inherited the reality that wild salmon populations are a fraction of their former numbers. It would be the greatest second blow to naturally producing salmon to advocate for the systematic closing of hatcheries. People condemn hatchery fish based on genetics arguments and competitive impacts to wild salmon juveniles. Both have merit. But we are well past the point of being able to sustain fishermen at the current harvest rate soley on the backs of wild fish. So I think it is better to be cautious about generalizing that we should shut down hatcheries as we seek solutions (and pay the price) to protect rebuilding stocks. In the meantime, freshwater and ocean rearing conditions, as well as viral and other disease threats are worth our attention. The role of ectoparasites, such as sea lice, enhanced by human farming, constitute yet another layer of complication.

This is more in line with my thoughts. So many problems, so many issues, so much politics.

First, we can eliminate the hatchery genetics issue if we simply use wild fish as hatchery sources. The largest loss of eggs is in the wild, and it is not due to genetics but the wild conditions. If every decade or so we purge the hatcherys and use the wild fish a source fish again, the genetics arguments goes away.

Without hatcherys, with Asian and Russian fishing ships and factory ships straining the seas for every last fish, there were be no fish in less than a decade.

The Sea Lions are far worse than most people wish to believe. For better or for worse, the dams are there, and they have created pinch points. The Sea Lions use these pinch points to feed like hogs to the trough. There is nothing natural here.

Tribal fisheries, well if the treaties had envisioned net that span whole or almost whole rivers, I doubt that there would have been the treaties. Only PC prevents us from stopping this right now.

Do you wish me to go on? What about a substitute for hydroelectric power? Perhaps you would perfer coal, oil, gas, nuke? Perhaps you want all of the people in the Northwest, except for those of us that fish of course, to leave so we don't need the power?

Sea Lice, yes, a problem, but let's not forget the forest just because we see a tree.

[lskiles]

But we are well past the point of being able to sustain fishermen at the current harvest rate soley on the backs of wild fish. So I think it is better to be cautious about generalizing that we should shut down hatcheries as we seek solutions (and pay the price) to protect rebuilding stocks.

My beef is not with the hatcheries, but with the farms. Hatcheries are good. Farms are bad, or at least badly placed.

[Fisherman_max]

so, since we all know SEA lice can not live in fresh water then why would the hatcheries have anything to do with the sea lice, all fish that go out to sea get them and the lice die soon after entering the freshwater. so why would the DEAD lice have an effect apon the later hatched juvinile salmon. if the lice did get into the system the wilds would be just as responsable for bringing the lice in, as the hatchery fish.

[Fish Antics]

I thought Anglinarcher's use of the term"pinch points" for dams is very descriptive. Imagine two thirds of the natural spawning substrate in the Columbia Basin being blocked (pinched off) by one dam. Look at the pinch caused by the dams creating the artificial 900 feet of vertical head on the Columbia and add thirteen mainstem dams and that adds up to a lot of physical pinch points for fish coming and going. Hundreds of more little dam pinches scattered here and there in the basin. Add the unnatural pinch of the sun's heating of the water in the (eastern) impoundments raising conditions above the lethal temperature tolerances of salmon, stimulating the unnatural reproduction of competing predator species adds more of a pinch. Add the pinch of point-source pollution including the contaminated headwaters and add the challenge of the race against time before biological systems within the fish are exhausted or incapable of expressing their destiny. Other pinches? .. dropping fish over spillways, smashing them into travelling screens at outrageous velocities, or worse, the pinch of NO-spill (controlled-spill . . . only if it's mandated!), - Some years, when flows have been low or the need to store water has been high there has been no spill (the eternally underestimated and transparent problem of successfully bypassing juvenile salmon past dams has been the incidious leading cause of mortality and the continuing demise of salmon on this river) Sprinkle into the mix our embarassing ability to measure the nitrogen supersaturation at the mouth or the Columbia, driven into solution by Grand Coulee dam, and others, during high flows.

For decades we have been systematically eliminating millions of juvenile salmon spring after spring, year after year.

And then, the ultimate pinch for traveling adult salmon that return to the home river is the unnatural shift of sea lion populations blocking the fish ladder entrance at the dams . . . Yes, I like the notion of "pinch" - unless we're the recipients of the pinch!!!

[A9]

so, since we all know SEA lice can not live in fresh water then why would the hatcheries have anything to do with the sea lice, all fish that go out to sea get them and the lice die soon after entering the freshwater. so why would the DEAD lice have an effect apon the later hatched juvinile salmon. if the lice did get into the system the wilds would be just as responsable for bringing the lice in, as the hatchery fish.

Re-read it all buddy. The hatchery fish vs. wild fish was brought up as a side tangent...