Zebra Mussels

[ScubaDo]

I read an article a couple months ago about how the ZM invaded the I believe it was the St. Lawrence River or one of the great lakes and it cleared up the water, but the ZM's were everywhere.  With no natural local enemies they are able to flourish, but someone discovered that there is a goby that originated from the same place as the ZM's, that feeds mainly on the mussels and therefore helps keep them under control. Has anybody heard of this and is there any work being done to promote this?  I have have seen many small gobies in the lakes around here and haven't seen any mention of them.  Anybody have some insight on this?

[DiveCaptDean]

I personally dont have any book knowledge of this, but as you are probably aware, the wrecks in Lake Michigan are coverd in mussles..there are also tons of small little fish that sit on the wrecks..mussles...i dont know what they are called..someone here does..they are roughly 11/2 to 2 1/2 inches long..they are everywhere..this may be what you are speaking of...

[schalge]

On Sunday June 4, 2006 The Appleton Post-Crescent had an article (by Jim Lee) titled "Winnebago sheepshead mussel up"
This article quoted several WI DNR sources that large sheepshead (freshwater drum) on Lake Winnebago have gone from 15" to 28" in size and that the belly's of these fish rattle as they are full of ZM shells.
I have copies of this very interesting article if anyone would like to see it.

[Swimjim]

I get up to Door county shore diving probably a half dozen times a year and I do shore diving in lake Michigan near my home.  I have been watching Gobi's the last few years and find them to be an interesting critter.  They do appear to eat zebra mussels.  I have seen them spitting out empty shells.  Two years ago while diving the Fleetwing, I took a new diver out to the deeper piece of wreckage.  As we swam out to it, I noticed that there had been a population explosion with the goby, they carpeted the bottom.  We settled down and laid on the bottom and were as motionless as possible.  The Gobi's came out to observe us.  They made a nice little ring around us and we had sort of a Mexican stand off.  Anyway, fast forward one year.  I was diving Porcupine Bay.  There were tons of empty shells, but only a goby here and there.  On the other hand, at any given moment your could see about a dozen small mouth bass and everytime they came near the Gobi's, the Gobi's would vanish.  I made a nice video out of it. 
     This progression leads me to believe that the zebra and the Gobi's are working their way into the food chain.  Mother nature is making adjustments for another one of our screw ups.  I think it's likely we will always have Gobi's,zebra and now quaga mussels.  I also believe that to attempt to do anything about it will further damage the environment. 
     The only invasive that really concerns me is the snakehead.  Lord, not if, but when those fish hit Lake Michigan, what will they do?  In a much larger environment will they grow enormous and start trying to eat divers?  Apparently they kill everything else.  Dang.

Jim

[ScubaDo]

I found the article mentioned online, but while looking, I found another article that pointed out the opposite in Lake Eire.  It seems that there are a number of other fish that eat the ZM also.  What I'm kind of getting at is, is the ZM really a bad thing?  We as divers would love to have better viz for diving, yes they may spread like crazy, but if Sheepshead and other fish enjoy them and help control them, why not introduce them to other lakes together.  From what I've read so far, ZM don't seem to hurt the fish, people just don't like them covering everything.  It seems like a cheap way to clean a lake.  One article mentioned that they absorb contaminates in dirty lakes and then the fish eat them.  I have an idea for that, build metal frames for the ZM to colonize on them and then remove and clean them and install the frames back in the lake.  You can also add or subtract frames to help control the balance.

[smoothfin]

spearguns and bangsticks, jim.

[Chris H]

Take a look at this
What part of that indicates any kind of control of the zebra mussels?  They wouldn't stay on the metal frames either.  They cover every square inch of anything.  Please don't intentionally introduce invasive species to a lake in hopes of better visibility.

Last summer I had the privilege of diving some wrecks off of Whitefish Point in Lake Superior.  Initially, when I got in the water I thought "Man the vis is horrible!", and I think it was a bit worse than other times I had been there, but I then realized how much better the wrecks were when they weren't covered with mussels.  There is still paint on the Vienna that looks as if it were painted yesterday. 

[Swimjim]

I'll just keep diving with you and Fred.  If a seven foot snakehead appears I am confident I can swim faster then both of you with that kind of motivation. Ha.

Jim

[Dewit2it]

I found a 1/4" zebra mussel on a rock in Redgranite last summer.  Where there's one, there's a billion more on the way.  Keep your gear clean!!!

It should be interesting to see what happens if they're reproducing in Redgranite.  It may be the end for the freshwater jellies, but then again, they have two ways of reproducing, so the mussels might not finish them.  The adults are also zooplankton feeders so the ZM larvae may be food for them.

Another interesting thing to the ZM problem may be calcium levels in the water.  If there's not enough calcium available the mussels may not be able to form shells, and in that case they're toast.

In any case, keep an eye on the rocks at Redgranite.

On Skumbago, I have had a front row seat on the invasion there.  In the bay I live on, the mussels grew wildly at first, with large amounts of full grown adults seen on the rocks.  Now, you see much smaller mussels in the 1/4-5/8" size range.  Most colonized rocks have only one layer of the mussels and very few on the tops of the rocks.  The tops of the rocks have large deposits of silt on them.  This silt seems to be from the feeding habits of the mussels, as it always seems to return after it should have been washed off after storms.  This may be preventing colonization of surfaces that in other areas, would have two or more layers of them.  I have noted that areas of the bay have filled in rapidly in the last 10 years.  Some spots are dry that were 5' deep.  So in some cases, they are causing themselves problems.

[ScubaDo]

I haven't been to any dive sites where ZM's were present, or haven't noticed them.  I'm not looking to help spread them, just been curious about them and wondering, are they getting a bad rap when there is some benefit to them.  I can see them being a nusance where wrecks are present, but what about Devil's lake, Red Granite, Wazee etc...  Would the ZM be welcome there for better viz?