Lake Stevens Alum Treatments

[Steelheadin360]

Has anyone looked into setting up an aquatic plant filtration system?

Good idea... But I think the cost and size are some limiting factors

[Steelheadin360]

Update from Lake Stevens

The treatments are going to take place March 9th- 13th. Also WDFW has moved the stocking date of the Kokanee smolt's back a few weeks till mid June. That will allow food production to be very high and the little guys should be fat and happy.

I am also working with a biologist to take water samples before and after the treatments to see if they help this year (unlike last year). If in fact the treatments fail this year the City will be looking into other options to control PHOS levels such as an updated aeration system.

Long story short. Fishermen- 1 Alum- 0

[Smalma]

Not sure this early alum treatment is a win for the fishermen; in fact I think it is the exact opposite.

In looking at the data from last year it is clear that the chlorophyll started to build this time of year and once the treatment occurred there were depressed levels for about 6 weeks. It is that chlorophyll levels that drive the engine that supplies the kokanee food (zooplankton). Treatment next week will drive the current low levels to even lower levels and they are likely to remain well below that 10 to 15 level typical of the conditions when we see significant feeding and growth of the Stevens kokanee until well into May.

The end result may well be that spring period where we see explosive growth of the Stevens kokanee will be shorten resulting in smaller kokanee than we would otherwise see and a bite delayed even further than normal. And it the end it may well lead to increased algae blooms in the late summer.

Hope I'm wrong but long story short looks to be fisherman 0 and alum treatment 0.

Curt

[Steelheadin360]

I do agree with the later treatment being the better option but it would really mess with the Late Spring/Early Summer fry plants. The Lake is almost in a full bloom right now. Chlorophyll levels are matching that of almost Late April last year. High oxygen levels and high external loading should allow algae levels to bounce back a little quicker then they do in May. I'm hoping anyway. Also most of the Kokanee Im marking are in depths of 40 feet of water or less. These are the first areas to warm and were the most food production happens. As the treatment is applied to the deeper water, these areas will remain almost untouched.

DFW liked the early treatment plan as did Lake Stevens and some of my School mates.

If the Alum treatments continue it will be the death of the Lake. I'm hoping this will be the last year.

[Smalma]

I understand the concern if May treatment impacts on the fry plants. Those small fry need find food almost immediately. However there may have been a way around that problem. During the 1980s department of wildlife had success with mid-summer fry plants. The advantage of course is larger fry the difficulty is fry survival in the warm water of the summer. The State was able to get around some of the temperature problems but towing the fry to the deeper water in a flooded pram. That helped temper the fry to warmer water and once over deep water the fry would only have to dive to the cooler water rather than swim a significant vertical distance to find that cooler water. Release the fry in the early morning would have slightly cooler temperatures and the increasing daylight help to encourage the fry to go deep.

The kokanee fishing was acceptable during that period with generally large but fewer fish. That size and abundance was more of a factor of the limiting the numbers planted than an issue with fry survival.

However sounds like the decision has been made - hope I will not have to look for an alternate fishery.

Curt

[Steelheadin360]

hope I will not have to look for an alternate fishery.

If current practices weren't changed, we all were going to be looking for somewhere else to fish. What I need is a round table with everyone who knows about this lake and we need to draft a plan and present it to Lake Stevens. WDFW is already well aware that the City has not put much thought into these treatments. And now the Mayor is becoming well aware of that too. This was a quick fix this year to make sure we have good fishing throughout April and May and into June. Next year hopefully everything will change and we can look into a non chemical way to restore the balance of the Lake.

[Smalma]

Steelhead360-

As you may recall I suggested that a get together would be a good idea a month or so ago but heard nothing.

While I know of Lake Stevens (and even bit about its fish and fisheries) clearly that knowledge was not needed to broker a "quick fix". At this point not sure what I can add to the discussion except to hope my fears prove to be unfounded (have often been wrong before).

Not sure what role "layman" should play in the development of a treatment plan other to be prepared to insure that such a plan considers factors outside of the immediate water quality/chemical factors of the treatment. Considerations of such things as impacts on the aquatic food web, the fisheries resource that supports and ultimate impacts on the lake's fisheries would seem to logical concerns. Do I dare say for some of the lake's users those are vital concerns.

I'm always anxious to learn more about the fish and fisheries such as what we have in .Lake Stevens that have brought me so much joy. As such I would be more than willing to bring what little I know or seen to a face to face discussion if you think it would be useful. My number that I sent you via a PM remains valid.

Curt

[Steelheadin360]

Email from Mick

FYI - The Alum treatment will begin on Monday morning (9th March) around 7-8 AM. The full application is expected to be completed by Wednesday evening. Mailers have been sent out to residents around the lake, a press release was issued, and notification signs are being posted at public access points. The weather is looking good for the application so delays are not expected. In the event the weather change, such as high winds, there may be some delays.

Under the application permit, swimming and recreational use of the lake is not restricted.

This year’s application had been moved from June to March in response to concerns expressed over possible impacts to the Kokanee. The Department of Fish & Wildlife had been informed and supported this action. In addition, they have alerted the City that the planting of Kokanee would occur well after the treatment is completed.

[Kelson]

S360,
First of all thank you for your insights and determination on this issue. Steven's Koks are a significant part of my recreational fishing. I was just made aware of your post and this thread. I don't have the knowledge you possess regarding the science behind the treatment and ecosystem. With that said, i have done some collection for the WDFW on Lk. Samammish in recent years and have a contact with the department. When i first learned of the Alum treatments I inquired with my contact. He made some inquiries and suggested that the WDFW was not aware of the planned treatments. I find it surprising that a permit process to do these applications would not require sign off by all interested parties.

There is no question that the fishery is changing (with that said, it can be the norm in the sport of chasing Koks). Please keep us posted on how we can help you in your efforts.
K

[Smalma]

Given the recent reports from Stevens and what appears to be some tough fishing I thought I would bring this thread back to the top of the Forum.

Unfortunately the concerns about the potential survival of the kokanee fry in 2014 appears to have been justified,

That concern was based on the lack of potential food resources available for those small fry. With adequate forage those small fry had little fat reserves to carry them through the tough times and their survival drops. The impacts from that poor survival is compounded by the continued annual treatments and the resulting limit on the food chain that supports the kokanee.

In the past when there were weak year classes of kokanee in Stevens (or other lakes) the survivors typically experience increased growth rates and larger sizes. This is important to the angler in a couple ways. The larger fish tend to be more aggressive which means they are more catchable. That catchability helps support catch rates above what it would be if the fish were smaller. And of course the additional benefit is that angler satisfaction is maintained with a smaller catch if the individual fish are significant larger. A few years ago instead of catching 11 to 13 inch fish we were catching significant numbers of 14 to 16 inch fish (4 to 8 such fish in a 10 fish limit).

I try to check back to this thread and attempt to answer specific questions.

A fellow Steven's kokanee fanatic.

Curt

[JoshH]

I am not one who can say whether or not the current struggles on the lake for fisherman is related to the alum treatments and any die off that may have happened, if this is a 1 year issue that since they changed treatment and planting dates will correct itself next year, if it will be an ongoing issue because of the treatments, or if it is strictly related to the weather we had this winter and spring. I do know that surface temps near the end of May this year are what they were near the first of April last year. Everything from me is anecdotal. All that I know is that folks who fish the lake a lot more than me are struggling. Whether that lasts all summer, or is temporary remains to be seen.

[Smalma]

Josh-

The first alum treatment on Stevens was in 2014 and was timed at about the time that the small fry were planted into the lake. A classic case of the WDFW, the City of Lake Stevens and the consultant not talking with each other. As noted in the thread I was concern that there could be excessive mortality on those fry; that appears to be the case. Fortunately changes in the timing of the treatment will likely avoid those mortality issues. Hopefully that will mean more "normal" numbers of kokanee in Stevens.

However the fry survival is only part of the story. The goal of the alum treatments is tie up the nutrients in the lake to avoid excessive blue/green algae blooms. That of course means that the kokanee will likely continue to average a smaller size than before the treatments started. The results of the Lake Stevens derby helps illustrates what the impact on the continued alum treatment may be on the kokanee in coming years. This was the 8 derby. For the first 5 years (where the kokanee were in-affected by the treatments) the average size of the winning fish 1.49 # (ranging in size from 1.26# to 1.68#) and the best 10 fish limit averaged 10.3#. For the three years since the beginning of the treatments in 2014 (after the May derby) the average winning fish has been 1.01 (ranging from 0.86 to 1.10) and the best 10 fish limit averaged 7.6.

Typically on a given Lake the average size of the kokanee in any year is related to the over all abundance of the kokanee. The more kokanee the smaller the fish. With the alum treatment Stevens has essentially become a different lake where we can still expect larger fish at lower abundances but just as large as in the past. The biggest question now is whether the continued treatment will cause a continuing lower of the lake's productivity resulting in even smaller fish.

One of the wonderful things about the Stevens kokanee in the past was at even relatively high destinies the average size of the fish were above average for many lakes and those densities support a consistent fishery with even the 10 fish limit. That appears to now be a thing in the past. A question for the managers (WDFW) will be whether some adjustment in planting levels are needed and what the appropriate balance between size and numbers should be.

To some degree it will be up to those that fish the lake to lobby how future populations and the fishery they support should look.

Curt