Zebra Mussels Confirmed In Susquehanna River Upstream From Chesapeake Bay - WP

[hatrack]

Oops.

The discovery of eight shells no bigger than a fingernail in Maryland waters has signaled the arrival of the exotic zebra mussels that have caused an estimated $5 billion in damage to the Great Lakes. If they spread, the invasive fresh-water mussels could threaten the less-salty waters of the Chesapeake Bay northward from Annapolis.

The zebra mussels found in Maryland apparently were transported on a recreational fishing boat that was plopped from a car trailer into the fresh waters of the Susquehanna River above Conowingo Dam. Whether that handful can get past the Harford County dam and into the Chesapeake may be a multibillion-dollar question. "If a bit of debris with a zebra mussel on it gets to the dam, it goes through," said Merrie Street, spokeswoman for Conowingo Dam. "There is no filter."

Power generation at the dam, which produces 572 megawatts of electricity for 13 states, including Maryland and Virginia, as well as the District, could be the first to suffer if the mussel population explodes. "I'm knocking on wood that we don't have a zillion of them by fall," said Jon McKnight, associate director for habitat conservation at the Maryland Department of Natural Resources.

Once zebra mussels become established in a large body of water, they are virtually impossible to eradicate. They are prolific breeders that overwhelm native species, but the more-expensive threat comes when they clog the valves on machinery including outboard motors, as well as nuclear power plants.

EDIT

http://www.washingtonpost.com/wp-dyn/content/article/2009/05/23/AR2009052301793.html

[OKIsItJustMe]

1. Wonderful

Well, I guess it was only a matter of time…

[MineralMan]

2. Right...it's always a recreational boat...

"The zebra mussels found in Maryland apparently were transported on a recreational fishing boat that was plopped from a car trailer into the fresh waters of the Susquehanna River above Conowingo Dam. "

This is what they always say. Well, here in Minnesota, they've turned up in a reservoir for drinking water for the Twin Cities. Oddly enough, recreational boating isn't allowed in that reservoir. The only boats that ever go on that lake belong to the DNR and the water district.

That lake also has a thriving Eurasian Milfoil colony, another non-native, invasive species. How did it get there? Apparently on the feet of water birds, who don't understand that they're supposed to remove all aquatic vegetation before leaving a lake.

The bottom line is that if there are exotic species in some waters, they will spread to other waters. It's not always the recreational boaters, although they are one source.

[OKIsItJustMe]

3. "Oddly enough, recreational boating isn't allowed in that reservoir."

Yes, and our cats aren't allowed on the table…

[MineralMan]

5. I've never seen a boat on that reservoir.

This is Minnesota, where there is a lake on virtually every corner. The reservoir doesn't even have a launch ramp. A couple of miles away is a very nice lake with a ramp and it's full of fish. There's no reason to put a boat on a lake where boating is prohibited in Minnesota. There'll be another one just down the road.

Your argument doesn't wash, I'm afraid.

[RaleighNCDUer]

7. Maybe not powerboats, but is there really anything to keep a kid

from putting a canoe in the water and paddling around? Particularly where boating is not permitted, so he knows he's not going to get run over by a powerboat?

[MineralMan]

8. Actually, a chain-link fence and no nearby

houses pretty much handle the kids in canoes. There's also an occupied pumping station on the reservoir.

Again, there are lots of lakes around that don't have power boats on them, too. As I said, recreational boats don't use that lake. Only DNR and water company boats. It's very likely that the zebra mussels came in on one of those. The eurasian milfoil was probably introduced by birds.

Most of the existing zebra mussel infestations are on the rivers here. They'll probably infest the lakes which are on river and stream systems connected to the river, but the spread will be by natural, not human means.

I know the Raleigh area. You have no idea how many boatable bodies of water there are here. I have at least 50 within a 20 minute drive of my house, and one just six blocks away, but it doesn't have a ramp, so it's mostly used by canoeists. Nice bass fishing in it, too, but it's too much hassle to drag my 12' aluminum boat down there, so I drive a bit and launch it.

All through the cities and suburbs around here are small lakes for kids to use their canoes on, and they do. A lot. All summer. Kids have trailers that attach to their bicycles to haul canoes to their nearest pond or lake. It's terrific.

[OKIsItJustMe]

11. What is the source of the resevoir?

Is it (for example) a stream or a river?

[annabanana]

4. Do they have a natural predator species?

What eats them?

[MineralMan]

6. Non-native species from the areas they originated.

Planting an exotic species to combat another one doesn't work out very well. It never does.

Zebra mussels can be a problem, but mostly due to their clogging up of water intakes in various places. Other than that, they don't cause all that much problem. They do over-filter the water in some places, causing a shortage of the plankton-like organisms eaten by slightly larger organisms, but that's not all that common.

The problem is that our waters lack predators that target zebra mussels, so they're prone to overpopulate and crowd out native freshwater mussel species.

But, the main problem is that they tend to clog up things like powerplant intakes and water system intakes, since they like the currents they find in them.

Oddly enough, lakeshore property owners like zebra mussels, since waters where they occur are generally clearer than where they do not.

[RaleighNCDUer]

12. Just import some fish to munch them up -

Chinese Snakeheads, anyone?

[Karenina]

9. THAT'S the real question. How do they taste?

:evilgrin:

[kristopher]

10. Just come up with a delicious recipe

And we'll be able to harvest them to extinction in no time...