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Thread: Turbidity on the Kenai whats your opinion?

  1. #1

    Question Turbidity on the Kenai whats your opinion?

    The turbidity issue is looming and Les Palmers article in the Clarion has brought it to peoples attention. If the Kenai is exceeding federal water quality standards due to turbidity, what are the solutions?
    More drift boat days? Its not just the guides as Sundays are just as bad or worse than the other days and then Monday(drift boat) the exceeding values disappear.
    What to do ???

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    Nothing you can do about it. Water swirls mud up off bottom, mud washed into river (big deal this year with all the snow), typical Feral gub'mint bovine fecal matter. Like the time the ferals were going to fine Anchorage big bucks for "particulates" (dust), when everyone was pointing out the dust was coming off the mud flats and nothing any human could do anything about. It took all the reps in DC to get the ferals to back off.

    So what will you do? You won't fish because the river is a river and the ferals can't tell what that is.
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    Wink And here we go again . . .

    —from the article mentioned above:

    The process of finding a "fix" for the turbidity problem will generate its own waves, and they'll be mountainous. Many people won't even acknowledge that turbidity is a problem. They'll say, "Lots of rivers are muddier than the Kenai, and they still have salmon." People with investments in boats, motors, land, homes, lodges, docks and other "improvements" will fight to keep what they've got. Sides will be taken, fingers pointed.

    A major problem facing those in favor of reducing the turbidity caused by boat wakes is that few of the effects of turbidity can be quantified. No one can answer the question, "How many more salmon will the Kenai River produce if all motors are banned?"

    If you thought previous battles over the Kenai were fierce, you haven't seen anything. I can already hear it: "You believe that garbage? The head of that group is a commercial fisherman! Those salmon chokers will do anything to get back some of the fishing time they've lost because of all the sport fishing on the Kenai."

    "If it wasn't for there being too many fishing guides, we wouldn't be having this problem."

    "I blame it all on Bob Penney. Before he came along, there was plenty of fish for everyone."

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    And away we go . . "Problem? What problem? . . . . . . .

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    The riparian zone (the interface between the river and its banks) is the part of the river occupied by juvenile salmon, and I have heard statistics like 80 percent of the juvenile salmon in the Kenai are rearing with 6 feet of the bank. Where those banks are armored by coarse gravel/rocks or woody vegetation, they are relatively immune to turbidity caused by boat wakes. This is the typical bank structure seen further upriver.

    The biggest turbidity problem is in the lowermost reaches of the river where exposed soils and muddy cutbanks dominate the riparian zone. These areas are incredibly susceptible to wake-caused erosion and turbidity. It's not uncommon to see powerboat wakes causing a 6-10 ft swath of muddy water tight to an entire 1/4 mile cutbank with a clearcut color-line demarcating the laminar flow of MUCH less turbid current immediately adjacent. So the question becomes, "What's the impact? And is it measurable?"

    Clearly there is some impact... it's visibly obvious the water has been disturbed for a sustained amount of time even after the wakes subside. But how much?

    If these are areas that would normally be occupied by rearing juvenile fish for extended periods of time, there would be considerable impact, perhaps causing the displacement or even the demise of some fish. If on the other hand, these areas are utilized mainly as migration corridors, the fish would only be subjected to the disturbance for the duration of their brief transit thru the affected areas.

    I'm no expert on the matter, but it makes sense to me that rearing juveniles would take up residence not just where food is abundant but also where they have plenty of structure.... rocks, stumps/rootwads/other LWD, and/or nearshore vegetation.... to offer cover from predators. This is NOT the typical structure found in the areas most prone to wake-caused erosion/turbidity in the lower river.

    Maybe an ADFG biologist who is a member of this forum can comment on this issue?
    Last edited by fishNphysician; 04-09-2012 at 18:53. Reason: GD % sign is STILL a pain in the arse
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    The other thing to consider is that every two weeks, the BIG tides cause tremendous outgoing currents that scour the silt/mud off the bottom and the exposed cutbanks of the entire intertidal zone. Turbidity naturally goes up twice a day during the ebb flow on these BIG tides. It's something to which the fish have naturally adapted in this section of the river.
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    Default Problem? What problem?

    Quote Originally Posted by fishNphysician View Post
    . . banks are . .relatively immune to turbidity caused by boat wakes. This is the typical bank structure seen further upriver.

    The biggest turbidity problem is in the lowermost reaches of the river . . So the question becomes, "What's the impact? And is it measurable?"

    Clearly there is some impact... . But how much?

    . . If on the other hand, . . the fish would only be subjected to the disturbance for the duration of their brief transit thru the affected areas.

    I'm no expert on the matter, . . This is NOT the typical structure found in the areas most prone to wake-caused erosion/turbidity in the lower river. . .
    Like Palmer said:

    Many people won't even acknowledge that turbidity is a problem.

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    Restore a 100 yrd buffer zone for the whole Kenai River and no motors above tide water! I think it's funny that you can't fish from a boat if the anchor is dragging on parts of the river but you can run a boat and put a three foot wake out and wash crap into the river. Let's make the Kenai great again remove all houses that are within 100yrd of the river!

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    Interesting problem. I heard back in January the Cook Inlet Driftnet Association is paying $10K for a lobbyist to push for restricting the use of props on the Kenia. Something to do with it causing too much erosion and turbidity. Appears they making some headway.

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    Cool Interesting hearsay . . .

    Quote Originally Posted by Halibutgrove View Post
    Interesting problem. I heard back in January the Cook Inlet Driftnet Association is paying $10K for a lobbyist to push for restricting the use of props on the Kenia. Something to do with it causing too much erosion and turbidity. Appears they making some headway.
    Those wascally setnetters again? This year, you say? Well, if that's the case, they're Johnny-Come-Lately to the party—the Kenai Watershed Forum beat them to it by years:

    Attachment 59025

    Turbidity in the Kenai River

    Beginning in 2008, KWF began monitoring turbidity in the lower Kenai River. Elevated levels of turbidity occur in areas where heavy boat traffic occurs for extended periods of time. The highest levels of turbidity occur near shore, which is important habitat for juvenile salmon. Turbidity interferes with the ability of juvenile salmon to feed.

    —much more at the link

  10. #10

    Default Drinking water standard exceeded, not fish and wildlife standard

    Turbidity in the Kenai River

    Beginning in 2008, KWF began monitoring turbidity in the lower Kenai River. Elevated levels of turbidity occur in areas where heavy boat traffic occurs for extended periods of time. The highest levels of turbidity occur near shore, which is important habitat for juvenile salmon. Turbidity interferes with the ability of juvenile salmon to feed.


    The state standard for impacts to fish and wildlife is 25 NTU's above the background levels, for more than 10% of the time. In the draft report for the Kenai River turbidity, it shows that the elevated levels of turbidity did not exceed 25 NTU's more than 10% of the time, meaning that for fish and wildlife the state standard is not exceeded. The draft report indicated that the drinking water standard, with a limit of 5 NTU's above background levels, for more than 10% of the time, were exceeded, while the recreational standard of 10 NTU's above the background levels, for more than 10% of the time, was near this limit.

    So the current data indicates that the standard for drinking water is being exceeded, in a tidally influenced area of the Kenai River.

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    Spoke to the lead guy at KWF this weekend.

    He agrees that prolonged increases in turbidity are generally observed only in the reach below Eagle Rock.

    He also agreed that the issue really hinges on what actually lives in that intertidal riparian zone, and how the increased turbidity affects resident fauna that normally lives there throughout the summer. That near-shore niche in tidewater has never really been studied or surveyed by ADFG in a comprehensive manner. The time period to get some sense of a baseline would be during the off-peak boat traffic months... see what lives there when it's not stirred up by wake. Then compare that to what lives there during the last 2 weeks of July.

    If the survey reveals significant numbers of parr, then it could definitely be an issue. If the survey is dominated by smolts, then those guys are merely passing through.

    As I said earlier, if that reach is utilized by juvenile salmon primarily as a migration corridor rather than as a nursery, the impact is negligible. Down-migrating smolts are merely getting an early "taste" of the silt/turbidity levels they're gonna encounter in the Inlet anyway.
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    Tubidity in the Kenai River is caused by to many people in boats, and on the banks of the river so to stop all the finger pointing lets just shut the whole river down to fishing and any other boating use! Then all we have to do is stop all the run off from roads, and remove all the houses from within 500 yrds of the river. With the above listed actions the Kenai River would be saved.

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    Anybody ever see what the Keeley River puts into the Kenai?? They need to put a dam up there and a filtration system, and we could go back to the good old days of unrestricted horsepower. My 24' jet boat put out out less of a wake than my current 20' with a 50 hp motor does...
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    Quote Originally Posted by jrogers View Post
    Anybody ever see what the Keeley River puts into the Kenai?? They need to put a dam up there and a filtration system, and we could go back to the good old days of unrestricted horsepower. My 24' jet boat put out out less of a wake than my current 20' with a 50 hp motor does...
    The Killey River is natural, your boat is not.
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  15. #15

    Default The issue really hinges on...

    Quote Originally Posted by fishNphysician View Post
    Spoke to the lead guy at KWF this weekend.

    He agrees that prolonged increases in turbidity are generally observed only in the reach below Eagle Rock.

    He also agreed that the issue really hinges on what actually lives in that intertidal riparian zone, and how the increased turbidity affects resident fauna that normally lives there throughout the summer. That near-shore niche in tidewater has never really been studied or surveyed by ADFG in a comprehensive manner. The time period to get some sense of a baseline would be during the off-peak boat traffic months... see what lives there when it's not stirred up by wake. Then compare that to what lives there during the last 2 weeks of July.

    If the survey reveals significant numbers of parr, then it could definitely be an issue. If the survey is dominated by smolts, then those guys are merely passing through.

    As I said earlier, if that reach is utilized by juvenile salmon primarily as a migration corridor rather than as a nursery, the impact is negligible. Down-migrating smolts are merely getting an early "taste" of the silt/turbidity levels they're gonna encounter in the Inlet anyway.
    The issue really hinges upon whether or not the drinking water standard will be applied in a tidally influenced zone of the Kenai River. That is the water quality standard that is being exceeded in the three years of data collected by the KWF.

    If we really want to know what a range of turbidity levels do to fish and aquatic life in Alaska, the study would be to look at the mouth / esturine zones of the Kenai River, the Kasilof River, the Susitna River, the Matanuska River, the Cooper River Delta, and other glacial rivers throughout Alaska to study what fauna live in these regions and what adaptations, if any, allow them to inhabit water ecozones that have extreme, fluctuating ranges in turbidity levels.

    If resident species of fauna live in the lower eleven miles of the Kenai River in the tidally influenced zone, then these resident species have to deal with swings in natural turbidity variation that range from 25 NTUs to over 3,000 NTUs, which is the natural range of variation in the lower section of the river throughout the year, as evidenced by the water quality data collected by KWF over the last decade.

    The KWF data indicates that the turbidity from boat traffic does not exceed 25 NTUs above the natural baseline leves at mile 11 for more than 10 percent of the time. That is the water quality standard for fish and wildlife. It was not exceed in the three years of data collection for turbidity monitoring by KWF.

    If resident species of fauna do live in the tidally influenced zone of the Kenai River on a year-round basis, then they deal with natural swings in turbidity from 25 NTUs to more than 3,000 NTUs, or a factor of magnitude of more than 100. If the natural baseline for turbidity in the non-tidally influenced zone is 25 NTUs, then an additional 25 NTUs above that would be one magnitude of order above the baseline level of 25 NTUs. The impact of boats on turbidity levels in the lower river in the tidally influenced zone did not exceed an additional 25 NTUs for more than 10% of the time in July (the busiest month for motor boat traffic on the lower section of the river.) This means that the turbidity levels generated by power boats are, on a sporadic, short term basis in July, less than one order of magnitude out of the total year-round variation of 100 orders of magnitude in the range of turbidity levels that any resident fauna living in the tidally influenced zone experiences throughout the year.

    Look at any aerial photo of the Kenai River - the tidally influenced section of the river has a distinctive, visable noticeable variation in color when contrasted to the non-tidally influenced section of the river above Eagle Rock.

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