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Captain's Cove

1/7/15 DEC Studying Ongoing Salmon River Steelhead Disorder

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DEC Studying Ongoing Salmon River Steelhead Disorder Nutritional Deficiency Strongly Implicated in Increased Steelhead Mortality in Lake Ontario Tributaries DEC Taking Steps to Meet Egg Quotas to Ensure Robust Steelhead Population

Adult steelhead (a strain of rainbow trout) returning from Lake Ontario to the Salmon River in Oswego County are exhibiting signs of stress and elevated mortality rates due to an apparent thiamine (vitamin B) deficiency, New York State Department of Environmental Conservation (DEC) Commissioner Joe Martens announced today.

 

DEC scientists enlisted the help of fish health experts in other agencies and academia to determine the cause of this disorder. DEC staff submitted moribund Salmon River steelhead to the Cornell University Aquatic Animal Health Program for testing. Results indicate that fish pathogens are not responsible for the abnormal behavior and mortality. DEC also sent steelhead samples to the U.S. Geological Survey's Northern Appalachian Research Laboratory for further lab testing. Results strongly indicate a severe thiamine (vitamin B) deficiency, which means it is likely contributing to the steelhead mortality.

 

"Lake Ontario steelhead are an important component of Lake Ontario's sport fishery and DEC is deeply concerned about reports of steelhead stress and mortality in the Salmon River and other Lake Ontario tributaries," Commissioner Martens said. "Steelhead provide high-quality sport fisheries in the open lake and are especially sought after by anglers who fish in tributaries from fall through spring. DEC staff will continue to work closely with federal agencies, Cornell University and other stakeholders to identify the cause of the current situation and strategies to ensure a robust steelhead population."

 

In mid-November, DEC fisheries staff began to receive reports of steelhead swimming erratically in the Salmon River and higher mortality of the species. More recent reports indicate similar behavior in steelhead in other Lake Ontario tributaries.

 

Steelhead are an important component of Lake Ontario's sport fishery, which a Cornell University study valued at over $112 million in angler expenditures in New York annually.

 

Great Lakes fish predators (including salmon and steelhead) that feed primarily on alewife are prone to thiamine deficiency. Alewife, an invasive bait fish in the Great Lakes, are known to contain thiaminase, an enzyme that degrades thiamine. A thiamine deficiency can impact egg quality and the survival of eggs and newly hatched fish, and, in severe cases, can cause the death of adult fish.

 

DEC is taking steps to meet its spring 2015 steelhead egg-take targets at Salmon River Hatchery, and will work with Great Lakes agency partners to provide assistance in meeting egg take quotas, if needed. Staff from DEC's Rome Fish Disease Control Unit and Salmon River Hatchery are preemptively injecting adult steelhead returning to the hatchery with thiamine. Thiamine-injected fish will be held in outdoor raceways at the hatchery and fed a diet fortified with vitamin B to improve the likelihood of successful steelhead egg collections in 2015.

 

However, little can be done to alleviate the mortality of adult steelhead that are unable to ascend the river and reach the hatchery's holding facilities. Although moderate thiamine deficiencies are not uncommon in top predator fish such as salmon, lake trout and steelhead in Lake Ontario and other waters, this year's acute deficiency is atypical in its severity. DEC staff will continue to collaborate with experts to further understand the circumstances leading to this year's mortality.

 

For more information, contact DEC's Bureau of Fisheries (Cape Vincent Fisheries Station) at (315) 654-2147.

 

 

 

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I don't get it.  Alewives have always been the main diet of steelhead.

 

Pete - your point is an excellent one.

 

Either the alewives now have some sort of a genetic deficiency causing them to have higher levels of thiaminase than they did before, or the high levels of thiaminase are coming from something else (i.e. bacteria, a virus, etc).

 

- Chris

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Steelhead normally have a diverse diet (bug, emeralds, shad, alewives,ect). TONS of alewives were high in the water column all summer this year. Did the steelhead eat more alewives than normal because they were readily available?

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My contacts in Canada told my of a 5-6 mile long school of YOY alewife on the surface over the "blue zone" in late August 2013. That would place them in the zone for steelhead to go crazy over the fall and winter of 2013/2014. Emeralds are WAY down in numbers but I have been finding steelies with gobies in their stomachs which are suppose to be a good source of Thiamine and counteract the Thiaminase effects of alewife ingestion. ?????? lots of questions.

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Steelhead normally have a diverse diet (bug, emeralds, shad, alewives,ect). TONS of alewives were high in the water column all summer this year. Did the steelhead eat more alewives than normal because they were readily available?

 

My contacts in Canada told my of a 5-6 mile long school of YOY alewife on the surface over the "blue zone" in late August 2013. That would place them in the zone for steelhead to go crazy over the fall and winter of 2013/2014. Emeralds are WAY down in numbers but I have been finding steelies with gobies in their stomachs which are suppose to be a good source of Thiamine and counteract the Thiaminase effects of alewife ingestion. ?????? lots of questions.

 

Also very good points. Come to think of it - I filleted only one steelhead this past year (over 10#) but it was absolutely loaded with alewives. I think therewas 9-10 in there. Maybe they are just eating more of them?

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Geez....I'm feeling better already ..... I should show this to my wife  :lol: it makes me look almost "normal"   :)

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To many alewife not enough kings to manage the base and cold water kept the bugs from hatching as soon. They did forage heavier in deep water on alewife. They were stuffed with them in my catches.

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To many alewife not enough kings to manage the base and cold water kept the bugs from hatching as soon. They did forage heavier in deep water on alewife. They were stuffed with them in my catches.

This is all true Skipper, but in the 80's they gorged on alewives and there were other severe winters delaying the bug hatches. I don't think they have this all sorted out yet. It would be interesting to find out if it has had more of an affect on Altmar hatchery fish than the wilds or Canadian planted Steel. 

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Vince,

This has affected fish all over the world, and other lakes in NY. We won't know if how diff it will be affecting wild vs hatchery since they are not clipping all steelies. Some of us believe the state should be clipping all hatchery fish, since we do own the trailer. We also believe the study for kings was not long enough. We need to know the cost to run the trailer, no need to implant chips, unless they want to do a specific study.

Like you said last season, a noticeable lack of of our top predators in the lake!!! Lots of questions that need to be answered, and that will not be answered at the SOTL meetings coming up. I will post some links to studies, interesting reading from all over the globe on this.

Capt Rich.

Sent from my iPhone using Lake Ontario United mobile app

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My only beef is clipping adds stress to the fish. Talking to the guy from the dec that delivered the fish to the pens last spring he told me the fish were stressed and did not eat for days after being clipped.

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I've always wondered why they can't just use small different colored plastic tags inserted by tagging gun or numbered ones in the dorsal for example rather than the clipping which not only may stress them but may make them less maneuverable in the water and make younger fish more susceptible to predation.

Edited by Sk8man

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I've always wondered why they can't just use small different colored plastic tags inserted by tagging gun or numbered ones in the dorsal for example rather than the clipping which not only may stress them but may make them less maneuverable in the water and make younger fish more susceptible to predation.

These are not 12" fish, they are YOY and tiny. Would be difficult to have a "tag" not alter the survivability. I wish they would stop handling them all together. Charter captains will hate me for this, but I think they should suspend the Pen projects until they figure out the disease process. Hatchery-to-piers....dump them in at night and walk away.

 

Especially after cold winters, the band of warm water along the shoreline is very tight.  Every Brown and Coho in the system is probably waiting to eat the baby salmon.....never mind the hordes of Lake Trout waiting just outside that shoreline band.  Perhaps, instead of asking our baby Salmon and Steelhead to try to make it thru the gauntlet of waiting predators present in such a tight window of warm water in early spring, we wait until the end of May to release the fingerlings when the predators have begun to disperse lake-wide (water temp permitting).  Just some thoughts.

Edited by Gill-T

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Main problem with stocking later in the Spring is that cormorants will be there in full force and will decimate them within days.  Need to do as much stocking before they show up.

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I don't get it.  Alewives have always been the main diet of steelhead.

Yes, but there's been an alewife explosion the last two years, so they are overfeeding is my guess.

Did you not see the HUGE baitfish balls all summer long in 2013 and even worse in 2014.

They are gorging on alewife, and essentially poisoning themselves. 

 

Less predators, due to mortality, will mean even more alewife, which will mean even more deaths.

 

I think they need to introduce Cisco to balance the diet of trout/salmon in Lake O.

 

Either that, or stock A LOT more salmon to get the Alewife levels back down.  But then you risk a baitfish collapse, and ultimately a salmon/trout collapse.

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I've always wondered why they can't just use small different colored plastic tags inserted by tagging gun or numbered ones in the dorsal for example rather than the clipping which not only may stress them but may make them less maneuverable in the water and make younger fish more susceptible to predation.

 

I read they were experimenting with a "dye/tattoo" system.  Basically like a bar code, but multicolored. It would then no damage the fish permanently, and it would not be a persistent impediment.

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This is all true Skipper, but in the 80's they gorged on alewives and there were other severe winters delaying the bug hatches. I don't think they have this all sorted out yet. It would be interesting to find out if it has had more of an affect on Altmar hatchery fish than the wilds or Canadian planted Steel.

I agree Vince, however i think the steelhead had a little more balanced diet as far as the forage fish are concerned. There were always a lot more rainbow smelt around back then and those have fallen off in density in the recent surveys. I believe maybe the steelhead are 90% fed on alewife. The smelt are the first thing in spring that the steelhead like to feed on after returning from tribs. If not as many found then the next best thing on the buffet is alewife for them.

Copied from the 2013 Lake Ontario survey presented in March 2014

5) cross-lake transects and an Eastern Basin transect. Estimated yearling and older alewife

abundance was 681 million fish, 3.5 times higher than 2012 and 3.7 times higher than the

previous ten-year average. The rainbow smelt population estimate was 19 million yearling and

older fish (Figure 3), the lowest estimate in the history of the survey (Section 24).

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Gill T - the tags I was referring to are technically called micro tags and they can be shot from a special  "gun" sort of like construction workers nail guns but are light plastic and obviously much smaller all the way around :)  I can't remember where I saw them as it was awhile back.  The tags were both colored and also had the capability of micro numbering for tracking purposes too. All that would be needed for diary cooperators are the colors instead of clips that was the thinking behind my comment and I should have been more specific.

Edited by Sk8man

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Les, the DEC trailer they have now can fin clip the adipose fin and place a "tag" in the nose of the fish I imagine not dissimilar to dog microchips.  Nothing is visible or impeding with those tags unless you feel like myself that shoving a piece of metal into the head of a fragile young fish has potential pitfalls.

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:)  I hear ya.

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