AIS question for Craig

[imajigger2]

Craig can you weigh in on this question posed in Minnesota? Thanks in advance.

What lakes have been ruined by zebra mussels. Some attribute clean up of Lake Erie to zebra mussels. Besides being nasty and clogging water systems any other negative impact you can point to.

[fishlessDan]

I would guess that they ear zooplankton(sp) that yoy need to feed on. And im sure there are plenty of other factors.

[imajigger2]

They are algae feeders, so while they may eat the same food as zooplankton, if zooplankton feed off algae, that would not be a problem in itself and possibly beneficial for algae blooms. Don't get me wrong, I still think at this point they are not a good thing but can find no evidence of any completely barren or sterile lakes or ruined lakes caused by Zeebs alone.

[Kansasoutdoorsman]

Two things I have seen first hand to the point, both are just my observations. One is Melvern, the lack of shad the last two years can directly be attributed to onset of the height of the zebra muscles population in that lake. They directly out competed the shad and have really impacted the overall size and quality of fish in that lake. The other thing I have seen first hand are the injuries that are happening. I have seen so many kids, adults and dogs hurt by cutting their hands and feet and needing stitches on the sharp little buggers. Now I don't think anyone can doubt there is both good and bad things they do but the over all health of most lakes that have then have had more major downsides on the fish populations than upsides. Thats just from an outside perspective.

[Blackdog40]

There are a lot of shad in Melvern this year

[zummy]

This is his reply to you from 3 years ago

imajigger2,

It has been nearly 8 years since the discovery of zebra mussels at El Dorado Reservoir. Zebra mussels have impacted the reservoir over the years and I have not seen a single positive impact. We experienced extremely clear water conditions during 2006 when the zebra mussel population was at its' peak density. 2006 was also a drought year at El Dorado which contributed to clearer than normal water conditions so it was a number of factors that contributed to unusually clear water. Whatever the cause was, gizzard shad densities declined. Zebra mussels and other filter feeders such as gizzard shad compete for similar food items. Gizzard shad fuel the sportfisheries in Kansas reservoirs. Without shad, sportfish growth rates suffer and recruitment decreases. Although many lake users as well as anglers liked the 'clear' water at El Dorado during this time period because it was 'pretty' and 'clean', they thought. Zebra mussels do not 'clean' the water, they only remove suspended components from the water column and deposit them on the bottom as pseudofeces. The lake isn't any cleaner than before the infestation, but the 'clear' water conditions offer reduced amounts of the needed biological soup that supports fish, native mussels, and other wildlife. El Dorado had its first zebra mussel population crash during mid-2007 and the zebra mussel densities dropped dramatically and thankfully have remained at lower levels since. Shad densities have since improved and body conditions of sportfish such as white bass and wiper have returned to acceptable levels.

Did the zebra mussels 'decimate' the fishery here? No, we still have fish and they were always being caught but the lack of shad necessitated the cancellation of planned predator fish stockings such as walleye and wiper. Sportfish densities decreased as species that are recruitment limited here (walleye and wiper) were not stocked. The high densities of zebra mussels that encrusted shorelines and underwater structure made fishing very difficult. Line abrasion and break offs were very common making most forms of fishing (jigging, trolling, etc) less productive as lures/baits were quickly lost as soon as the line contacted the sharp edges of the zebra mussel shells. Some anglers that thought they liked the clear water and thought the zebra mussels were a benefit at El Dorado quickly changed their minds as encrustation continued to increase and fishing became increasingly difficult.

We have been in the 'rebuilding phase' at El Dorado for the last couple of years. The return of productive shad spawns have allowed fish stockings to resume and for naturally recruiting species to benefit from young shad during the growing season. Recruitment rates have increased leading to increased densities of fish anglers pursue, we just need a little more time with desirable conditions to let these fish reach catchable sizes.

In short, luckily the peak infestation densities were only seen for a short time at El Dorado and the fish and the lake have had some time to recover. The million dollar question is when will the zebra mussel population again increase in density? Another of my lakes (a 1,250 acre city owned lake) has had zebra mussels for nearly 5-years and it has not responded in a similar manner to what El Dorado did. Each lake is different, weather patterns and flow through rates affect colonization rates of zebra mussels, nutrient levels vary from lake, available habitat for zebra mussels vary, all of these and many others make a lake's reaction to the infestation differ impacting some more than others.

The zebra mussel invasion is still relatively new to Kansas waters and we are learning as we go as far as impacts to our aquatic systems. As I said before, I have not seen any benefits to fish or the angler from the zebra mussels, only negative impacts which are far reaching including negative impacts to nongame species, industry, hunters, and recreational users. Hopefully Kansas lake users will work hard to protect the zebra mussel free lakes that we do have. When a zebra mussel management solution is discovered it would be nice to treat a small number of lakes vs. the entire state and all its' watershed.

Here's a picture of El Dorado late September 2006 showing the high encrustation densities seen during the zebra mussel population peak.
Attachment 65320

[imajigger2]

I remember this post well. I support the clean drain dry. My question more to the point is what lakes have been ruined for fishing by zeebs and what other ramifacations come with the zeebs regarding fishing other than making them harder to catch. The water clearing and the line abrasion thing just makes fishing these lakes more challenging for us as anglers, one could argue the point that zeebs do more for curtailing limits of fish being removed from these lakes than other methods. Below is a post I found interesting from an anglers point of view.


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We unfortunately have ZM in the majority of lakes where I live. I don't hear any reports of fishing collapsing. People are still going out, catching fish, vacationing, ect. The local paper is still filled with beautiful fish being caught. Is the water clearer? Yes. Is the weedline deeper? Yes. Have the lakes become vast lifeless voids filled with nothing but weeds and zebra mussels? No.

I don't ever hear any stats about how the lakes with ZM have declined. Where is that data. All I hear is the sky is falling and the world is coming to an end. ZM is not the first invasive species introduced to our waters by man, that included intentional stocking.

We could close every access, have every boat inspected and decomtaminated, and the I am willing to be the spread will continue. Don't birds/ducks/geese/pelican fly from lake to lake?

While it would be nice to eliminate ZM or stop their spread, I think it will be futile.

[Craig Johnson]

Craig can you weigh in on this question posed in Minnesota? Thanks in advance.

What lakes have been ruined by zebra mussels. Some attribute clean up of Lake Erie to zebra mussels. Besides being nasty and clogging water systems any other negative impact you can point to.

imajigger2,

I can't answer for Minnesota lakes. All of my lakes that have zebra mussels have been negatively impacted. The addition of a nonnative invasive species is not good for any water body as native species and desirable sportfish species are negatively impacted.

See post below for a partial listing of negative impacts.

[Craig Johnson]

They are algae feeders, so while they may eat the same food as zooplankton, if zooplankton feed off algae, that would not be a problem in itself and possibly beneficial for algae blooms. Don't get me wrong, I still think at this point they are not a good thing but can find no evidence of any completely barren or sterile lakes or ruined lakes caused by Zeebs alone.

imajigger2,

Zebra mussels feed on plankton. They do however select against consuming blue-green algae so by removing other plankton components that reduce blue-greens they can actually provide better growing conditions for the harmful blue-green algae thus increasing densities of these toxic algae.

[Craig Johnson]

...Don't get me wrong, I still think at this point they are not a good thing but can find no evidence of any completely barren or sterile lakes or ruined lakes caused by Zeebs alone.

If your definition of "ruined" equates to "completely barren or sterile" then you likely won't find ANY lakes that have been "ruined" by zebra mussels.

If your definition of "ruined" includes degradation of native habitat, reduction of forage fish density, reduced quality of spawning areas of sportfish species, reduction or elimination of native mussels, decreased body condition of sportfish, decreased density of sportfish, increased injury to humans through cuts caused by sharp shells, increased water bills, increased costs of maintenance to water control structures, buoys, and docks, increased clarity of water (which equates to decreased productivity) to name a few, then you will find many lakes that are less than they were prior to infestation.

Zebra mussels, and any other ANS, take up space in a water body. The more you have, the less room there is for other organism such as forage or sportfish. Can zebra mussels remove ALL LIFE from a water body? I've never said that zebra mussels are capable of causing completely barren/sterile lakes, but apparently someone has and they are using this as their argument that zebra mussels aren't so bad.