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Was it really the 2 year olds that came to spawn?


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After listening to Steve Lapan last week at the Irondeqoit Game and Fish Club, I was left wondering about a lot of the graphs that he showed us. Specially the one in which he showed that there is a direct correlation between the lake temperature and the feeding and growing behaviour of the Chinook. The temperature graph that he showed was of the Buoy off Rochester and in correlation the growth rate of the Salmon which stayed stagnant until the water temperature reached 50 degrees and above. In 2015 this happened well over a month later than other years. Not only did it take until mid June for the water to reach 50 degrees.The temperature stayed well below the average normal well into july while it finally came close in August. ( It did not completely catch up )

One can only assume that with the same severe winter in 2014 a simular delay in rising temperatures happened. That means 2  much shorter growing seasons.

All of this probably caused the salmon to stay well below their genetic potential and caused their growth to be seriously delayed or maybe even halted. However,their biological clock kept on ticking and the still small 3 year olds probably lost at least one and quite possibly one and  a half growing seasons (the very cold start in 2014 and the same cold water in 2015) because just as the water temperatures started to rise over 50 degrees in July 2015 they started directing their energy toward milt and roe.

All of this leads me to suspect that what we presumed to be sexually mature 2 year olds may very well have been small three year olds,while the larger ones probably lived in the warmer plumes of the rivers that flow in the lake. For example the Genesee or the Credit and the Oak.

Is all of this nonsense or am I on to something here?

Edited by rolmops
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2 year old's are called Jacks and Jill's, it is very common for all ocean run salmon returning to spawn with big numbers of Jacks and Jill's among 3 and 4 year old fish to spawn. There was a great article written by M Currier  biologist with California Fish and Wildlife...Now the Feds and even state hatcheries go by his findings to keep the species strong.

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The metabolism necessary for growth in all fish species is controlled by water temperature. That is why fish hatcheries depend on  warmed spring water, fifty five degree F., to grow their fish over the winter. In the wild streams the eggs do not hatch till Springtime warm causes the hatch and wild fish are small and become fodder for the large fish in the lake. They are not large enough to survive out there.

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I put together a graph from our intake temp at work and it shows a huge difference from the temps at the buoy.  remember the huge temp break that never moved in 200' fow for weeks the past two seasons?  The lake at our intake temp was above 50 degrees for 194 days in 2015 (the lake is way warmer right now than it was the past three years at this time and this is also the longest span of above 50 degrees since 2011).  If you go by the buoy data, the lake was only above 50 degrees at the buoy for 146 days in 2015 (which is the coldest it was in the 6 years of data I looked at.  If I get more time today, I will try to put the data up. 

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Those smaller fish are 2 year old fish. They do take scale samples to verify the age of the fish that they are taking eggs from, they do not age those fish based on size. So their data is pretty accurate. The big question is why are so many fish maturing at age 2, and not age 3? And why is recruitment down?

Sent from my iPhone using Lake Ontario United mobile app

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FWIW, My father had some Canadian Biologists out in the summer of 2014 that were trying to tag Atlantics for a tracking study.  They kept catching these tiny king salmon and were interested in the age so they gave my father a permit to keep some and ship them to them for aging.  The next week he sent them 18 fish between 10 and 16 inches long.  The 10 to 13 inch ones were yearlings, the 13-16 inch fish ended up being two year olds.  Those are pitifully small and I would say that there were most likely some small 3 year old matures around this year.  

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FWIW, My father had some Canadian Biologists out in the summer of 2014 that were trying to tag Atlantics for a tracking study.  They kept catching these tiny king salmon and were interested in the age so they gave my father a permit to keep some and ship them to them for aging.  The next week he sent them 18 fish between 10 and 16 inches long.  The 10 to 13 inch ones were yearlings, the 13-16 inch fish ended up being two year olds.  Those are pitifully small and I would say that there were most likely some small 3 year old matures around this year.

HHmmmm, that's is really interesting.

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There may be a genetic un-natural selection that has gone on in recent history.  Within this decade we had some difficulties obtaining enough eggs from brood stock to meet the hatcheries quota.  That meant hatchery employees could not be as selective in which adults are used for egg and milt.  If there were a lot of 2 year olds used due to a lack of three year olds getting up to the hatchery from getting caught by fishermen easier in shallow water we may have inadvertently selected for fish that run in two years.  I also don't know if it is hatchery policy to select only three year old brood stock........BUT IT SHOULD!

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Lapan said they take from all year classes.  He also said it should not affect genetics.  I'm not too sure I believe that. 

There is genetics and genetic potential. If a fish cannot live up to its genetic potential for whatever reason it will remain smaller. And if remaining smaller causes more successful survival then ,that is what will become the dominant population.

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Lapan said they take from all year classes.  He also said it should not affect genetics.  I'm not too sure I believe that. 

I've heard Lapan say that as well but I don't really believe it.  Just look at the different wild stocks Kings for example the large Kenai kings that reach maturity around years 6 and 8. In theory if you took eggs from these fish you get 6 to 8 year old fish or in our case if you took eggs from 2 year old fish you would get 2 year old fish more often then not, because that's the dominate genetic make up of the fish you are getting the eggs from.

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People visiting the hatchery during egg/milt taking have noticed hatchery employees just grabbing fish and not really selecting the biggest/fittest.  Human nature would dictate if you were picking up large slippery awkward fish all day, the back and shoulders might get a little sore.  Whether subconsciously or consciously we all might start to grab the two-year olds after awhile.  That is why it needs to be policy to only strip 3 year-olds.

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I asked specifically if there was a protocol in selecting fish at the hatchery to strip or milt and was told they take any size or age salmon to reach there number they need.  NOAA states Chinook salmon produce 2500 to 7000 eggs depending on size.  That means on the low end of eggs per fsih you need 800 hens to get 2,000,000 eggs and on the high end you need 267 hens so probably between the two number is the numbers actually need to meet the goals.  Realistically I would hope that the hatchery is getting many more hens than that and they could be more selective if they wanted to.  

 

Having said all that I do respect the work done by the hatchery and DEC guys.  We have had a World Class fishery for many years and they undeniably were at the center of that.  I would hope that past success has not impacted there ability to change procedures to match the changes the fish and the lake have gone through.  There should be diversity in eggs and harvest from all size fish should occur, but I would prefer a majority of fish, if available, should come from larger and more mature fish.

Edited by pvelyk
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Lapan said they take from all year classes.  He also said it should not affect genetics.  I'm not too sure I believe that. 

I think I agree with Gambler, but at the same time Steven is correct as well

The original salmon eggs that were introduced were from the Tule strain originatating in the Columbia River. They were the eggs of very fit salmon that were capable of swimming lots of miles (hundreds?) in adverse circumstances. And all the weaker or slower or smaller ones were weeded out by this murderous migration from and to the spawning beds. Yet at the same time the genes that produced these weaker fish were also present in the gene pool of the stronger and larger fish, which is proven by the weaker ones reappearing during every migration.

Then they came to lake Ontario. Their spawning migration up the Salmon river really was an afternoon outing compared to the long trips up the Alaskan river. This caused a lot of the smaller and weaker salmon to survive along with the fittest and strongest ones. Survival of the fittest does not happen in times of plenty it only happens in difficult times and with plenty of alewives to go around, slowly the smaller and weaker ones increased in numbers and percentagewise became a bigger part of the whole.

This does not explain why the forty pounders are gone, but it does explain why there are so many smaller ones.

 Lack of competition allows for greater variation and eventually more succesful mutation.

It may well be that we helped this process along by cuddling the fry even more with our pen projects. ( Can anybody make a connection between the first few years of the pen projects and the dissapearance of the 40 pounders?)

This process happened within the same genepool and its variants. So Steven Lapan is correct there.

Also I would like to know if the DEC has actually done a DNA map of the Lake Ontario salmon and compared this to the same strain on the west coast just to confirm that it still is the some gene group or if there were significant mutations that went unnoticed.

Edited by rolmops
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As to the original post, the returning STOCKED Salmon were predominantly 2 yr old matures as evidenced by the missing adipose fins from the clipping study. Although the study was compromised by not clipping the 2012 yr class, there were a few 4 yr olds(2011 yr class) out there clipped and the 2 yr olds( 2013 yr class) were clipped. Of course not all of the 2 yr olds matured and returned but it does seem to be an increasing trend. Also remember any natural contributors of any year class would not be clipped. Experienced West end Lake observers all reported the same thing, smaller returns of only stocked Chinooks, and the majority of them were 2 yr old clipped fish. Lapan promised to have their nose tag/scale sample data by the State of the lake mtgs.

I would not expect to see this same increasing trend of younger mature returning fish expressed by the wild population, as in the wild kingdom the biggest, baddest hook jawed Males and pot bellied hens get the primo spawning gravel. It's probably smart to take fish for eggs and milt the same way. 

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Lapans comment about fifty degree water made me think about something. The lake is clearer and kings seem to be spending more time in deep cold water to get away from sunlight. If the salmon are spending more time in 39 degree water, their metabolism will be slower. Is this contributing to smaller fish?

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It is an enigma. On one hand the theory that colder water reduces metabolism and therefore feeding and ultimately size. Charter captains I know have log books that seem to confirm this. On the other hand is the theory that more two year old kings run when they experience lots of food..... So which is it....are they feeding or are they feeding too much???? I would bet the temperature of the ocean in Alaska stays pretty cold. The fish evolved to exist in cold climates. Scroll down once you are on the below link and you will see Alaska ocean temps don't really get above 54 degrees. Different strains up there compared to the Tule strain of Kings we have which came from warmer Washington waters but it shows Kings should not care about 39 degree water. The mean temps off Washington seem to show 40-55 degrees most of the year which is the temp we usually find them in Lake Ontario.

https://www.nodc.noaa.gov/dsdt/cwtg/all_meanT.html

Edited by Gill-T
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Great ideas. I don't ever post but reading this through I had some stupid questions so here goes..... Regarding Alaska kings and cold temperatures.... Kimgs can probably eat in 39 degree water but maybe that's why they stay out in the ocean for 6-8 years? Regarding the idea about more 2 year olds lately in the spawning runs..according to ageing at the hatchery in dec reports from 2010-2013 age 2s did dominate the run but in 2014 age 3s dominated. Age 3s dominated run from 2004-2009. From 96-2003 age 2s dominated and from late 1980s-1995 age 3s again so it changes in periods. Why would this be if genetics had something to do with it.? Regarding the idea that the hatchery could select age3s on the fly during spawning -how could they know the age quick enough to select them if age 2 and 3 fish overlap so much that it's hard to tell them apart by looking at them?. Regarding temperature data from the intake, isn't this in the nearshore and on bottom and would this be indicative of salmon growth? Could size of kings and what ages dominate be related to how many prey are in the lake, how each years fish survive and ,grow, survival of wild fish, differences in pen fish survival and growth, catch rates and how many kings and other predators are in the lake compared to prey, and especially water temperature and length of growing season? Or all of the above? .seems complicated.

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Great ideas. I don't ever post but reading this through I had some stupid questions so here goes..... Regarding Alaska kings and cold temperatures.... Kimgs can probably eat in 39 degree water but maybe that's why they stay out in the ocean for 6-8 years? Regarding the idea about more 2 year olds lately in the spawning runs..according to ageing at the hatchery in dec reports from 2010-2013 age 2s did dominate the run but in 2014 age 3s dominated. Age 3s dominated run from 2004-2009. From 96-2003 age 2s dominated and from late 1980s-1995 age 3s again so it changes in periods. Why would this be if genetics had something to do with it.? Regarding the idea that the hatchery could select age3s on the fly during spawning -how could they know the age quick enough to select them if age 2 and 3 fish overlap so much that it's hard to tell them apart by looking at them?. Regarding temperature data from the intake, isn't this in the nearshore and on bottom and would this be indicative of salmon growth? Could size of kings and what ages dominate be related to how many prey are in the lake, how each years fish survive and ,grow, survival of wild fish, differences in pen fish survival and growth, catch rates and how many kings and other predators are in the lake compared to prey, and especially water temperature and length of growing season? Or all of the above? .seems complicated.

The intake is  in 50' of water in the Rochester basin. 

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