SML Striper Growth

[Deleted]

Bigun...you just summarized my thoughts exactly. At Lake Anna you could count on catching your biggest fish during the spring and summer after a major threadfin kill. The problem there is that ALL the big fish get caught and eaten that same year. The fish would literally explode in size then just disappear to either the bottom or to the knife.

With the regulations on SML...more fish can get through a year without being killed and will at least have the chance to grow. Well...that is if you leave the status quo alone.

To me..a safer move would be to stock threadfin for a few years. Keep everything else the same. Then push the reset buton and establish a consistent and reliable data gathering plan.

As I read these posts I'm just baffled that the same people who think that fishing pressure is a problem are the same people who want to pressure the average fish more. And I do see their rationale but to me..hope and tinkering are too risky. A slim chance to get the old days back might just get the old days back. However these old days might just be 2003 or even worse.

However in the same breath.. I'm 100% proud to be taking part in a discussion fueled by a community that loves their lake. You all are real good folk!

[CorneliaGale]

I did find out the Water Authority don't take samples of the lake any more, they did when I started working there 30 years ago. Would have been good to see them and how much if any difference in the lake water. Will try and go by the Health Department when I get a chance and see if anyone I know still works there and see if they do anything on the lake anymore. At least this is giving us something to talk about this winter.
Come on spring, only 40 more days or so.

[Bert]

I'm one of the guys that fished the lake since the early 70's. Lots of changes have taken place in that time. I think the biggest is the amount of bait in the lake. If you think the lake has a lot of bait now you weren't around in the prime. I knew one of the 1st biologist that worked on the striper stocking in SML. His last name was Hart, Larry or David, I don't remember his first name. Went out on the lake with him a couple of times doing surveys. The single biggest change was when Roanoke put in the sewage treatment plant. It did clean up the water tremendously. Hart said that at it's peak the lake had around 5000 ponds of shad per acre, after the sewage plant it went down to 800 pounds per acre. I'm sure older guys remember when the Roanoke arm was called "the sewer" and with good reason. The things that were seen floating, well I thing you get the picture, made the lake rich, the water was green with alge. Huge schools of gizzard shad everywhere, early on there weren't any throw nets, people used bluegill for the most part. We used to get the gizzards by snagging or using a landing net to flip a couple into the boat. Another big change was when people learned to use cast nets and started pulling bait on multiple rods. Lots more fish started being caught by more and more people. We all know deadly bait is on big fish. Another change was the amount of fish being stocked. There was a lot of arm twisting by the striper club to stock more fish even though the biologist were against it. You can only feed so many pounds of fish per acre, a lot of small ones or a lesser number of bigger ones. So you wrap it all together and this is where we are today. I'm not sure stunted is the correct word but it sure fits the problem as described.

[Deleted]

Ha!!! yep, I've used my share of bluegills & snaged gizzards back in the day.

But good lord, wonder what the bait per acre is now.......800lbs doesn't sound like much to me.....especially since we all probably gill & kill a big amount getting decent bait for a couple days sometime......are we contributing to the decline of bait thus hurting the fish we are trying to protect???    dang, I hope some funding comes through from somewhere...so much unknown...so much data needed.

[nkingfish]

Have not seen water temperature suggested as a potential variable impacting fish growth.

An extreme case is Lake Anna. Stripers essentially stop growing or lose weight during the summer months when temperatures rise to high levels.

Larger fish would have higher respiration rates with elevated temperatures - along with having greater energy (food) input needs during warm summer months. When respiration rates approach energy intake, you get slowing or no increase in biomass. This is observed in fish aquaculture in lakes/ponds during the summer months.

It really doesn't take much of temperature rise to impact respiration - since biological systems are very sensitive: typically respiration rates increase 2X to 4X for a 10C (18F)increase. This could mean that just a 2F increase could increase respiration 20 to 40%.

Since the growth rate problem has been observed in a number of southern lakes - may want to examine a variable that is similar across all of them.... and temperature would be one variable which would probably qualify.

I have been looking for an on-line database of water temperature for SML - but have not found one yet. Anyone know if there is a database?

[mwardncsu]

The best resource for temperature data that I know of is the Smith Mountain Striper Club's FB page - in the "Notes" section - has water temperature readings across depth (usually taken at Hales Ford Bridge) going back a few years.

I think I have some Temperature / DIssolved Oxygen data from Dan tucked away somewhere - but it was some some years back and just a few instances of data.

[mwardncsu]

I will say Anna and SML are quite different - isn't Anna fairly shallow? We are fortunate at SML to have good oxygenated cold water refuges for Striper in the summer and we don't seem to get the summertime "pinch" that a lot of lakes do where the fish have to retreate into low DO water to get to cool enough water.

[hillbilly]

I dont' have an answer, but i can make a few comments and observations on what has been said:

- does a shortage of threadfins make a difference - i don't know. but I will say based on my experience there arent' many in the lake. I never see them or catch them. All the small bait fish I come across are small gizzards.

- I also personally dont' come across as many alewives as a few years ago. that may just be me

- as to pressure on the lake - I'm not as much concerned about fishing pressure as some others seem to be, but I do feel there is more surface pressure every year by pleasure craft. and I think this pushes the fish, particularly the larger ones deeper. I know during the spring night fishing season, all the day boat traffic with skiiers, tubers, and runbouts tends to keep the surface at circus levels until after dark......and the night bite seems to start later every year, and last for a shorter period of time every night.

- And as far as winter season. While I appreciate and love the fact that stripers are a cold water/weather fish, I think the last two years of cold and often changing weather has had an impact on feeding cycles. The temperatures are up , then they are down significantly. the water levels have been very low at times (last couple springs) then back up to full pond as it has been this winter.

- I think the copods absolutely do have an impact on the fish growing bigger, and generally thinning out the population. how could they not, they are parasites living off the bodies of the fish?

- are fisherman harvesting too many fish? I have no way of knowing. but based on what this group has been reporting over the past couple years, I would say not. And if I had to wager, I would put money that if there are lots of fish being caught on the lake, this group is better at it than everybody else put together. so hard for me to imagine others are taking an abundance of fish out of the lake.

Final thought - After this crappy winter I'm really looking forward to spring fishing season. And to be honest, I'm afraid that the cold weather is going to cause a late start to spring and then summer will come quick and the spring season is going to last all of about 2-3 weeks. If so, more grumbling to come.

[BentRod]

Bigun, there's some fish that are slipping through and growing fine. The majority are hitting a wall around 26-28". Now they're growing some up into the 30"+ range as they age into their later life I'm sure but they're never going to be 40lbers. If they're 32" 14yr old fish, forget about it. I caught a 36.5" tagged fish last year that was 36.5" two years before that. They're stuck. What Dans seeing in his data is that the 8yr old fish are getting smaller every year..the 12yr old fish are getting smaller every year..every year class after about age 5-6 is getting smaller on average every year that passes. This why he feels we need to act. He's been watching the lack of growth for a few years and thought maybe there was nothing we could do..figured it was related to the Copepods, but then he noticed the growth starting to go backwards. He started looking at Leesville (who have copepods also) to compare. Leesville stripers are growing normally (as they always have since the 90s), so that's when he said, wait a minute, something's not right on SML.

I agree with you that bait could be the problem. But we have what we have for bait (outside of getting Mward money and dumping a truck of fertilizer in at Hardy every morning)..hence lets see what a reduced Striper population does to growth? I think it's entirely possible that 2-3yrs ago (putting us around 2010, which was the last time growth appeared decent) when our threads died and there was no bigger shad in the lake, that the bigger fish stunted. Now that we've got our shad back good, maybe we will see growth pick back up in the younger fish without any regulation changes at all. But our shad has been solid since fall 2012 and last years numbers didn't look good...it's really anybody's guess as to what's going on....maybe nothing at all...

Feb 7, 2014 20:08:57 GMT -5 Yam said:

To me..a safer move would be to stock threadfin for a few years. Keep everything else the same. Then push the reset buton and establish a consistent and reliable data gathering plan.

NOOOOOO!!!! Ha hell no. They might be a good food source, but the threads cause us all kinds of problems when they die off. They were a big cause of the 2003 fish kill. They overpopulate thinning out the gizzards then you get a winter like this one where water dips below 40deg for an extended period and they're all dead..come spring and early summer, the stripers are in trouble. Stripers can do fine without threads..they do it in plenty of other places. And yes I'm fine with reducing the numbers of average fish IF it enables our fish to grow normally. The only reason we have so many 28" fish right now is because a 6yr old fish is same size as a 10yr old fish.

Bert, you're correct that the Striper club pushes for high stocking which is why we are running into this issue to be honest. Dan says there was a promise made to them to push the system as hard as possible so we're constantly on the brink of overpopulation I think. I'm sure you could stock 150,000 a year and we'd never have to worry about any of this. But you'd have a tougher overall fishery for numbers..probably be some monsters around though. The Striper club is used to the high stocking of the past when Dan says survival was very low due to poor transportation of them. But over the last however many years (think it goes back to the late 90s), they've had better equipment and survival is very good. They were overpopulating the system before the 2003 kill also. The threads all died..no bait left..the Copepods hit and the big fish were so stressed..BAM..disaster.

[CorneliaGale]

A little history on the sewage treatment plant.
Plant has been in the same place since 1951 when the plant was built, a few small upgrades and then 1974 a major upgrade, and then a few small upgrades till early 2000's then the last major upgrade. Plant is rated at something like 100 million a day, average flow used to be about 30 to 35 million a day, the only time the plant should overflow is when there is there a lot of rain and the plant goes to maximum and the holding ponds get full it can overflow into the river, but still has been given some treatment. VTsuperfluke would know flow rates now, I've been gone about 5 years. Years ago the plant could not handle the flow and did overflow. Now they get fined if they do DEQ stays on their butts about any thing that gets into the river. I do remember that at one time there was no algae growing in the river for a ways down from the plant that has changed, there was trout at the outfall of the plant. They claim that the water coming out of the plant is cleaner than the water you drink. The plant supervisor used to take a glass and drink it when he did tours. I know for sure that they clean the water a lot better now than years ago. Another reason I feel that is making the lake water cleaner is the growth on the shoreline, houses instead of farms, you don't see farm animals in the lake too much anymore. More things to think about.

[Deleted]

NOOOOOO!!!! Ha hell no. They might be a good food source, but the threads cause us all kinds of problems when they die off. They were a big cause of the 2003 fish kill. They overpopulate thinning out the gizzards then you get a winter like this one where water dips below 40deg for an extended period and they're all dead..come spring and early summer, the stripers are in trouble. Stripers can do fine without threads..they do it in plenty of other places. And yes I'm fine with reducing the numbers of average fish IF it enables our fish to grow normally. The only reason we have so many 28" fish right now is because a 6yr old fish is same size as a 10yr old fish.
----------------

This makes total sense to me. However, this never happened prior to 2003? At Anna..a good portion always die off and thus they don't overcrowd the gizzards. From reading Biguns post..it seems a die off each year happened in the good ole days. Did we have some really warm winters prior to 2003? Interesting stuff.

I'm still puzzled at acting now. There has been no forage data collected for a awhile. And the collective conscience of the lake seems to think the bait is plentiful. And I can state unequivocally that the fish I caught in my 4 trips to SML last fall/winter were much bigger than the 2013 sample data I was given. That sample data shows only one big fish and most everything else below 30". Either I was one lucky SOB or this data is not representative. I have pictures of 8 fish that are 33-35 and a picture of a 25 pounder that I did not measure because we were rushing to get him back in the water. Although I will concede that my average fish size or probably better stated as modal fish size was around 27-28 inches. Yet my one boat caught 9 fish in 4 trips that are 3 standard deviations above the mean of the sample data? No way. A stats guy would conclude the 2013 sample data is wrong. I can't speak to the data of the other years.

Tyler think about what you have caught. Is it similar to the 2013 data? Could it be that the fish growth you were expecting this year has happened? I have seen some pictures of some pretty big fish on your boat.

[Deleted]

Thanks Tyler, I don't have the data in front of me that you do....what you are saying, from the data you are seeing makes sense........just have 1 more question.....if this is the route we go (reduced stocking numbers and the culling of the 23-29 inch fish).....how long would this proposal be in effect??....Seriously, it  wouldn't take long for just the members of this site to put a hurting on the smaller fish if directed to do so.  I'm willing to try anything, but just afraid before the data can be collected and sorted , the damage to the fishery will have been done...... while we are culling the smaller fish from the lake, say the proposal works and the yearly stocked fish catch up with the stunted fish in growth and are doing good.....how the heck are we supposed to know which is which?  ....sorry for all the questions....just really really concerned. Don't want to hurt the entire fishery just for sake of a few bigger fish.

[BentRod]

Nobody's saying to go kill all those fish guys. You know I'm releasing either way. The point is to get a few more of those fish out normally over time. It's still a 2 fish limit..sure a few more will go to box in winter months (summer is same), but overall I don't see it devastating the lake's population.

No Copepods before 2003 Yam. We don't need to stress these fish any more than possible. Now it's certainly possible that threads may hang at the perfect depth for our SML stripers, but I would think they're very similar to gizzards in that respect. Stripers will go to the depth of the bait if the water temp is right too, so summer months would be only difference. I'm as puzzled as you, but it makes sense to me that less stripers will mean better growth of the stripers there unless there's some other problem. This seems like a good first step to me.

[Deleted]

Feb 8, 2014 10:07:54 GMT -5 BentRod said:

it makes sense to me that less stripers will mean better growth of the stripers 

That can only be if there is a bait problem. Same with a deer heard, not enough food = stunted growth.....unless or until we can do something to have a more consistent bait population year in and year out, we are stuck where we are at, no matter what is done......the good ole days are called that for a reason....they are gone.......I'll leave this topic alone now. 

[Deleted]

Feb 8, 2014 10:07:54 GMT -5 BentRod said:

No Copepods before 2003 Yam. 

So to clarify. Before 2003, there was a healthy threadfin population that typically died off in the winters to some degree.  However, by 2003, the threads had somehow taken over the lake from the gizzards.  This may have been due to lack of nutrients or higher temps in the winter or both.  I assume lack of nutrients, because this board suggests that there was a healthy gizzard population in the past when wastewater plants were not overly regulated by the EPA.  So...in 2003 an abnormally cold winter coupled with an abnormally high population of threadfin essentially killed off all of the threadfins. And the the low gizzard population that existed did not satisfy the needs of the hungry striper.  I can only guess that many striper must have gotten huge after this 2003 threadfin kill. A feast of magnanimous proportions must have occurred followed by a bunch of fat lazy fish and some overly paranoid gizzards. Then FAMINE!  Only this famine, which may not have been abnormal was accompanied by those bastard copepods leaving fat stripers with an even higher need to eat food that is not only absent but would be hard for them to catch anyway because they are fat. FISHKILL!

Correct me please where I may be wrong.  I am hungry to understand this beyond what the papers say.

BTW, I manipulated the fisherman catch data a bit.  As shown below, the probability of catching a striper larger than 30 inches has been around or above 15%.  In other words, for every 100 fish caught, 15 are larger than 30 inches.  Of course, as shown in the data, 2004 and 2005 sucked!  Yet, this lake rebounded fast!  And here we are today with the same probability of catching a fish greater than 30 inches as we had prior to 2003.  Additionally as shown below, the 2013 sample data brings this number down to 7% which doesn't correlate with my own personal observations.  The 2011 and 2012 sample data did in fact correlate with fisherman data.  And unfortunately, I don't have the 2013 fisherman data.  This is why I am suspect of making decisions based on 2013 data.  I agree that the data suggests a growth stunt after 2003.  But anecdotal data suggests we have an awesome gizzard population that has finally evolved and 2013 numbers that don't seem correct.

I will refrain from further comment on this matter.  



In the meantime, it seems that we all need to jump in the water this summer and take a dump!  

PS Hehe...my wife thinks I am writing a paper.  Little does she know that I am in my office fishing.  Muhuuuhaaa.