Zebra mussels... whats the risks?

[Jackdaw]

After being 'introduced' in Lake Minnetonka 2 years ago, these things have exploded, pretty much covering anything and everything smooth on the bottom of the lake. Bottom paint keeps them off the hull, but is there issues/worries about things like engine cooling water systems? I've got the only diesel inboard at WYC so there is no one I can ask locally.

http://www.dnr.state.mn.us/invasives/aquaticanimals/zebramussel/index.html

 

[alexco38]

We have it bad in Lake Ontario. Just make sure you paint the engine intake grill with anti-fouling. Also put in a raw water strainer. Other than that just live with it.

 

[philwsailz]

I too have zebras at my lake. I got to see how quickly they can cover casting cavities on an outboard motor bracket on a pontoon boat over the course of 8 or so weeks.

My understanding is that they cannot survive the heat of the motor, as 140 degree water will kill them, (western states invasive species treatment for fishing boats and ballasted wakeboard towboats) but I would be concerned about them restricting water intake right at the thru-hull.

As a result of my research with Maine Sail here on the forums, and talking with the folks at Groco while I was at IBEX, my plan when I get to it to combat them will be the following:

Replace the current clam-shell thru hull strainer with a straight non-strainer mushroom thru-hull, the bigger the better, (I was thinking I may as well go 1.5"... more on why the large size in a minute).

Install a new flanged seacock on the mushroom thru hull

Install hose to the seacock that is long enough to extend above the waterline when extended in-line with the seacock.

Install a basket-style strainer inside the engine compartment, and use a reducer on the outlet side of the strainer to get back down to the raw water pump's inlet fitting.

The idea is that if and when the little buggers get to a point whewrer they are restricting flow at the mushroom thru hull, you simply disconnect the hose from the basket strainer and use a long dowell through the hose, seacock, and thru hull to rod out and clear out the built up clump of mussels...

To be totally clear, most of this information came from elsewhere, it was very little original thought on my own, so credit where credit is due, to Maine Sail and others who helped me come to this solution.

 

[Merlin Clark]

Phil,
I kept a short length of cheap plumbing snake onboard my last inboard engine boat (GS41) to use where your dowell would come into play. My engine room (under the center cockpit) didn't have enough room above the strainer connection to allow for a rigid ramrod, plus the Perkins would have been in the way because of the angle of the thru hull and seacock. The snake worked well on the engine intake thru hull, seacock and hose.

 

[FourPoints]

They showed up at our family lake house in north central Indiana about 10 years ago... They were so bad at one point it made swimming dangerous because you could easily cut your feet if you stood up. It is incredible ow quickly they can grow on everything.

We never had a problem with them on the ski boat though, probably because we kept it on a boat lift.

 

[philwsailz]

Phil,
I kept a short length of cheap plumbing snake onboard my last inboard engine boat (GS41) to use where your dowell would come into play. My engine room (under the center cockpit) didn't have enough room above the strainer connection to allow for a rigid ramrod, plus the Perkins would have been in the way because of the angle of the thru hull and seacock. The snake worked well on the engine intake thru hull, seacock and hose.

Nice point and great idea...

 

[Steve Dion]

Clams in Lake Tahoe!

This is how they are dealing with them

(http://terc.ucdavis.edu/research/aquaticinvasives.html)

 

[Winkfish]

Are they good to eat? Cook 'em up right and your problem is solved. Think of all the new businesses and jobs that'd create, too. ;-)

 

[kpgraci]

Are they good to eat? Cook 'em up right and your problem is solved. Think of all the new businesses and jobs that'd create, too. ;-)

Spoken like a true New Orleanian. I was thinking the same thing.

 

[DougM]

the problem is not the mussels, but their larvae. If the boat sets for awhile, the larvae ingested into the cooling system grows into mussels with shells and can in time clog up the system.

 

[Jackdaw]

the problem is not the mussels, but their larvae. If the boat sets for awhile, the larvae ingested into the cooling system grows into mussels with shells and can in time clog up the system.

I head that. I also heard that making sure your engine runs at least once every 7-10 days makes sure they cannot take hold. No idea if this is true.

 

[kpgraci]

I head that. I also heard that making sure your engine runs at least once every 7-10 days makes sure they cannot take hold. No idea if this is true.

So the solution is to sail more?

 

[Chris Patterson]

Seems like, if it were a huge problem, and I'm "hearing" it is, a man could rig up a water circulating system using a second electric bilge pump, and a Y valve near the engine. It would have the added benefit of washing water back through the strainer in the opposite direction, effectively keeping the strainer clean.

Just a thought..

 

[Jumpstart]

Geez Louise, we've had Zebra mussels on Lake Erie for 15 years or so. It used to be if you left a line in the water for a couple of days you would end up with a necklace which was not an exaggeration. The mussels have diminished a bit and I'm not sure why. Predators are one reason along with lack of a food source eventually. They don't stick to VC 17. If you put a brush with bottom paint on it up your water intake in the spring they are not a problem. Only seem to be a problem for municipal water intakes and nuclear reactor cooling water intakes.

 

[wflowe2]

We have them in our lake. I too have had success using anti-fouling paint up inside the raw water intake for the engine. I do get them in the strainer for the HVAC water intake. So far it hasn't been a big problem and I have only needed to clean out the strainer annually when I winterize.

 

[finding41]

Our lake has them too. I used a water based ablative paint and didn't have any crispy critters when I pulled out. I keep the outboard and rudder out of the water when at dock.
Here is a pic of my bottom once I pulled out at the end of the season. I'm happy with the paints performance.
This is what I used: http://www.canadiantire.ca/AST/brow...aguard+Blue+Boat+Paint,+1+Quart.jsp?locale=en

 

[jackhartjr]

Was cleaning the bottom of a boat on Kueka Lake NY, (Spelling) in 2001 and cut the crap out of my hand on them!
Jack

 

[jibes138]

I can't see them as any worse than barnacles or oysters. I am a barnacle and oyster farmer, not by choice but by reality. I have had the raw water strainer totally clog with oysters, my prop and shaft need regular cleaning to get the little critters off and my rudder was a mess last time I pulled the boat so now I make sure I use a extended handle broom to get rid of the slime on the rudder every time I visit the boat. I used Interlux Ultra my last haulout and I have going on three years with the current coat. Seems to be working very well. If you have zebra muscles you will probably need to clean your hull once a quarter or so.