Zebra Mussels

[Karyon]

Here in Canada there are no zebra mussels (only in lake Winnipeg), those mussels can do a lot of harm to our ecosystem.When we tow our boat from lake to lake there are check stops where we have to go thru and the officers will check your boats bottom, thru hulls, keel trunks etc. If they do find them on your boat you have to go thru a special line where they steam clean and power wash the bottom. Been thru a few check stops and it only takes 10 min, depending on the line up. If you pass by a check stop towing a boat they will chase you down and give out a fine.

https://www.albertaparks.ca/albertaparksca/science-research/aquatic-invasive-species/

 

[Scott T-Bird]

That's kind of a blanket statement about these particular mussels doing harm to the environment. They existed in another location long before they came to the US. Were/are they doing great harm there? It is a matter of adaptation, something that Earth does with and without our influence. Upheaval in the environment has been the norm for millions of years. Does it really matter how this particular event was stimulated? I'm not sure that these types of infestations are damaging in the long run. Just sayin' ...

 

[Cest La Vie]

John:
As a boat owner on Lake Texoma, we were the first in Texas to experience zebra mussels. Not sure of the exact time period, but probably have had them for almost ten years. We don't seem to see the quantity of these pests that we saw in the early years-probably due to the flushing of the lake after three years of massive flooding. That said, they still exist, but create no real problem for either sail or power boats here on the lake. We occasionally find three or four of the little pests on the top of the rudder when we haul out to paint or power wash the bottom. I have never seen one attached to our hull. On one occasion, I discovered a lone mussel on the paddle wheel for the knot meter that prevented the paddle wheel from turning. As others have noted, the mussels did actually provide for some clearing of Texoma, a lake not known for its clarity. Bottom line, I would not lose a lot of sleep over this issue.

 

[Gunni]

When I was learning living-off-the-land skills one of my favorites was Coquina broth. Also known as clam liquor. These are the small mollusk you find in the surf zone on a healthy ocean beach. About the size of your fingernail. You don't eat the meat, you simmer them and drink the broth, which you can spice with burdock, dandelion, clover greens, etc., or add some fish if you can catch them. Very tasty. I imagine these little zebra mollusks would be about the same.

 

[dlochner]

That's kind of a blanket statement about these particular mussels doing harm to the environment. They existed in another location long before they came to the US. Were/are they doing great harm there? It is a matter of adaptation, something that Earth does with and without our influence. Upheaval in the environment has been the norm for millions of years. Does it really matter how this particular event was stimulated? I'm not sure that these types of infestations are damaging in the long run. Just sayin' ...

Zebra mussels cause several problems and there are no natural predators to keep them in check. They colonize hard surfaces displacing native organisms, they remove large quantities of plankton reducing the available food supply for other native species. The water becomes clearer, which allows weed growth in deeper waters upsetting the natural habitat of native species. And then they clog up water intakes for fresh water supplies and cooling waters for power generating stations.

Here's what the Minnesota Sea Grant says: Zebra Mussels Threaten Inland Waters | Minnesota Sea Grant

 

[Ron20324]

+1 to Lochner.

 

[JerryA]

We have them in Lake Erie. But they aren't much of a concern for me. In the past ten years I can only remember a few that I've found on the boat when it's hauled. I do use VC17M and I sail almost every weekend. This past season I had one on the speed transducer when it was hauled. They have improved the water quality in the lake. Some of our beaches on the Western end of Lake Erie are covered in crushed Zebra shells. Some several inches deep. They're something you get used to.

JerryA

 

[Scott T-Bird]

Zebra mussels cause several problems and there are no natural predators to keep them in check. They colonize hard surfaces displacing native organisms, they remove large quantities of plankton reducing the available food supply for other native species. The water becomes clearer, which allows weed growth in deeper waters upsetting the natural habitat of native species. And then they clog up water intakes for fresh water supplies and cooling waters for power generating stations.

Somehow, it doesn't seem that simple. According to another article written about Lake Ontario, salmon fisheries appear to be benefiting. It seems that the clear water makes alewives healthier because they rely upon sight to feed on tiny shrimp near the bottom. Salmon also rely on site to feed on alewives. The improved weed growth provides shelter for all kinds of organisms to thrive, which is also benefiting the fisheries. I find it odd that in some cases we decry the devastation of filter feeders in Chesapeake Bay, which is why the water is so murky. Here we have filter feeders providing water clarity in the Great Lakes and we're going to condemn that, too? We could condemn salmon in the Great Lakes as well, being that they are an invasive species (invited and introduced by humans, but invasive, nevertheless). This article also suggests that perch feed on the mussels, so I'm not so sure there are no native predators. Something seems to be balancing the population. It may just take time for other predators to catch on to the gravy train.
As far as clogging water intakes ... so what. It doesn't hurt us at all to create jobs in cleaning the intakes. The weed growth in deeper waters is just restoring the balance that we had when the waters were cleaner in the past.
It seems that there may be some inconvenience to boaters due to the zebra mussel infestation, but, so far, it doesn't sound like it is that big of a deal.

 

[justsomeguy]

...suggests that perch feed on the mussels, so I'm not so sure there are no native predators.

The perch are eating whatever the mussels have filter-fed upon, including PCBs and heavy metals, providing a path upwards in the food chain.

Oh, Clostridium botulinum too.

 

[Scott T-Bird]

The perch are eating whatever the mussels have filter-fed upon, including PCBs and heavy metals, providing a path upwards in the food chain.

Oh, Clostridium botulinum too.

I agree, conventional wisdom says that the toxins do less harm when concentrated in the sediment and more harm as they are distributed though the food chain. Also, the bio-waste from the bivalves ain't so healthy, either. I'm not sure I agree in the long run.

 

[dlochner]

Somehow, it doesn't seem that simple. According to another article written about Lake Ontario, salmon fisheries appear to be benefiting. It seems that the clear water makes alewives healthier because they rely upon sight to feed on tiny shrimp near the bottom. Salmon also rely on site to feed on alewives. The improved weed growth provides shelter for all kinds of organisms to thrive, which is also benefiting the fisheries. I find it odd that in some cases we decry the devastation of filter feeders in Chesapeake Bay, which is why the water is so murky. Here we have filter feeders providing water clarity in the Great Lakes and we're going to condemn that, too? We could condemn salmon in the Great Lakes as well, being that they are an invasive species (invited and introduced by humans, but invasive, nevertheless). This article also suggests that perch feed on the mussels, so I'm not so sure there are no native predators. Something seems to be balancing the population. It may just take time for other predators to catch on to the gravy train.
As far as clogging water intakes ... so what. It doesn't hurt us at all to create jobs in cleaning the intakes. The weed growth in deeper waters is just restoring the balance that we had when the waters were cleaner in the past.
It seems that there may be some inconvenience to boaters due to the zebra mussel infestation, but, so far, it doesn't sound like it is that big of a deal.

Scott,

We've been dealing with zebra mussels on Lake Ontario for around 30 years, what you're saying is inconsistent with my experience on Lake Ontario. Can you site your sources for your information?

40 years ago, before the zebra mussel infestation and before the stocking of salmon, the alewife population was out of control. By June the dead alewives were 6 inches deep on the shores making the shorelines uninhabitable. Once Salmon were reintroduced in the 1970's the alewife population began to decline. Prior to the construction of the St. Lawrence Seaway, Lake Ontario was open to the ocean. Salmon freely migrated up the St. Lawrence and into the Lake.

There was a "bubble" in the zebra mussel population and it has declined in recent years (as measured by the zebra mussels on my boat and on the dock floats) but I'm more inclined to believe that the decreased food supply for the mussels has more to do with the population decline than an increase of predator species. Although, the recent infestation of Round Gobys (another invasive species introduced through bilge water in ocean going boats) may have had a slight impact as it is rumored that they will eat zebra mussels.

As for the increased job opportunities for those cleaning the intake pipes, I beg to differ with your opinion. These guys don't work for free and it is my water bill and my electric bill that are funding them. I'd prefer to direct those funds to something more enjoyable, like boat parts.

Dave

 

[dlochner]

A couple of days after my last post on this topic, I stumbled upon a documentary on invasive species in the Great Lakes. Finally got around to watching it this evening (Thank you Tivo!)

It was a fascinating and informative documentary. If you get a chance to watch it, do so. It is being broadcast on PBS stations. Here's a link to the website: http://www.makingwavesdocumentary.com

 

[Bob J.]

The perch are eating whatever the mussels have filter-fed upon, including PCBs and heavy metals, providing a path upwards in the food chain.

That's interesting because Lake Erie is pretty shallow & I read somewhere it is the largest perch fishery in the U.S.

 

[justsomeguy]

...I read somewhere it is the largest perch fishery in the U.S.

A good portion of the lake is in Canada, too.

Mmm, fresh walleye caught off Pelee Island. Another little thing I miss about that area.