Zebra Mussels Marching Steadily Inland Into Wisconsin's 15,000 Lakes - MJS

[hatrack]

EDIT

Politicians have tried for years to force overseas freighters to treat their ballast water - used to steady the ships - before discharging it at a Great Lakes port in exchange for cargo.

The shipping industry acknowledges the trouble it has pumped into the world's largest freshwater system, and its leaders profess a desire to do something about it. Yet at the same time they have consistently fought regulations proposed by Great Lakes states to require freighters to install onboard ballast treatment systems, claiming they are impossibly stringent, expensive or inconsistent from state to state.

Members of Congress, meanwhile, have repeatedly vowed - and repeatedly failed - to craft an overarching national ballast law that is palatable to both the shipping industry and environmentalists. The result is the door remains open to invasions, the most recent being the "bloody red shrimp" discovered in Lake Michigan in late 2006. There could well be others that have arrived since then; it can take years for populations to grow big enough to be noticed.

Biologists say the damage being done to the world's largest freshwater system cannot be overstated, but the problem has become bigger than the Great Lakes themselves. It's now clear the failure to slam the door on new Great Lakes invasions has consequences for everyday folks with cottages on inland lakes, places working-class people across the state like to claim as their favorite on earth. "Where is the fun in playing on the shoreline anymore if our lakes are wall-to-wall zebra mussels?" asks Dailey. "Look at the money that we all pay in property taxes to live on a lake that is now not the lake that it used to be."

The potential economic impacts of this second-wave invasion could prove staggering. Property on Forest County's Lake Metonga sells for an average of about $1,200 a shoreline foot, and the lake has roughly 7 miles worth of it. That means a crude estimate of just this lake's shorefront value - not including any of the homes built on it - lands somewhere above $44 million.

EDIT

http://www.jsonline.com/news/wisconsin/68119707.html

[AtheistCrusader]

1. The receiving port has the right to control this.

So the failure is Congress's. Or you could even look to the state level if you wish. Port state controls can be set at either level.

It's unrealistic to expect any corporation to regulate itself.



Can these zebra mussles and red shrimp be eaten? Is there a predator we can introduce that can keep them in check?

[hatrack]

2. Zebras are inedible; don't know about the shrimp . . . predators?

Good question . ..

[AtheistCrusader]

4. Of course, even introducing whatever normally eats these things carries risks.

But when an invasive species is out of control, there are many options to be looked at, at least.

[happyslug]

8. Actually Crayfish love them, but the lakes are colder then the waters further south

Predators of zebra mussels

There are a number of natural predators of zebra mussel. Zebra mussels have high nutritional value (Walz, 1979) and are consumed in large quantities by crayfish, waterfowl and in smaller quantities by muskrats. The nutritional value changes seasonally, particularly in terms of protein and carbonate content.

Crayfish could have a significant impact on the densities of 1 to 5 mm long zebra mussels. An adult crayfish consumes an average of nearly 105 zebra mussels every day, or about 6000 mussels in a season. Predation rates are significantly reduced at cooler water temperatures.

http://en.wikipedia.org/wiki/Zebra_mussel

Catfish also seems to love them:
http://cat.inist.fr/?aModele=afficheN&cpsidt=13927216

It should be noted that Crayfish are less active and eat less at lower temperatures and this may explain why the worse of the problems of the Great Lakes and Zebra Mussels have NOT been seen elsewhere (i.e. the crayfish and other predators eat to many of them as the Zebra Mussels get into the warmer waters as you go south so the number of Zebra Mussels are to small for them to block as many pipes as they do in the Great Lakes). This is pure speculation on my part, but the problems of the Zebra Mussels have NOT been seen even in the Allegheny's (the Zebra Mussel is in the Allegheny but you do NOT hear of the blockage of pipes as you do from the Great Lakes).

[Viking12]

6. The Freshwater Drum (aka sheephead), a native species in mny of WI's lakes does eat the zebras

[Viking12]

3. I live on the shores of Wisconsin's largest inland lake, we're almost at 10 years post-infestation

of zebras and to be honest, there haven't been any noticeable adverse effects on the ecosystem. The fish populations are still very robust. There have been discernible changes, however. The water is much clearer due to the filtration potential and thus more sunlight penetrates and we get more weed growth. That has actually provided more habitat for species of panfish (bluegills, crappies, and perch) and those fish are flourishing. The real significant change has been in the 'human systems' that use the lake -- the zebras attach to any stationary, hard surface and have caused major problems with water intake at our water treatment facility. We just spent millions of dollars to upgrade the system to keep ahead of the prolific little buggers.

[malakai2]

5. I think the big change over time is nutrient sequestration

I remember reading somewhere that as the mussel population grows, in the absence of a predator or parasite, the mussels sequester much of what's available, and what they excrete is largely consumed by a few types of benthic cyanobacteria. Maybe that was more theoretical, looking at smaller closed systems, I don't recall. Not sure how that would play out in Winnebago, but if there's nothing to control mussel density and they're capable of outstripping nutrient inputs and suspended solids already, I wouldn't think the changes would be positive over a long period of time.

[Viking12]

7. One of the 'defenses' Winnebago may have that other waters don't is that it is very fertile

There's no shortage of nutrients to maintain a large, dense biomass.