New underwater organism fouling boats in the river

Gilligan

#*! boat!
PREMO Member
Any marine biologists in the house? Seems we've got a new (invasive?) organism that rather dramatically fouls the underwater gear on our boats. Never seen this "stuff" before...it's rapid growing and almost appears to be some form of a coral. The spongy-looking mess is actually shell or similar, although not particularly strong. Can break off clumps of it with your hands, although you have to watch out because the "shells" have thin sharp edges.

The pic below shows how the stuff completely enclosed a propeller, strut and rudder blade, all in one big mass. This is on a boat, hauled at Tall Timbers yesterday, that's hauled and painted every year but was not actually run since last November. Yard guys at Zahniser's are reporting the same stuff is fouling boats over there too, so it's not limited to only the lower Potomac.


IMG_2353.JPG
 
Last edited:

black dog

Free America
That's really interesting, makes me glad I decided against keeping the sailboat for the summer near Buzzy's so the kid could use it..

Was this boat docked in a deep water or a mud slip?
Lots of sun maybe?
 
Last edited:

Gilligan

#*! boat!
PREMO Member
That's really interesting, makes me glad I decided against keeping the sailboat for the summer near Buzzy's so the kid could use it..

Was this boat docked in a deep water or a mud slip?
Lots of sun maybe?

Covered slip in the Tall Timbers basin. Been in the same slip for many years.
 

black dog

Free America
It will be interesting to follow this.. my tub is in Coinjock for the next month or so.
I hope this isn't a problem there also..
 

Gilligan

#*! boat!
PREMO Member
It will be interesting to follow this.. my tub is in Coinjock for the next month or so.
I hope this isn't a problem there also..

Eventually I'll get in touch with someone at the U of MD Biological station and see what they can tell me. And/or DNR..
 

black dog

Free America
Is this something the Biological lab on Solomons Island would be interested in?

My roomie has some kind of masters in biology or something like it.. but all I have ever heard her talk about was counting birds and different fish,snakes birds and stuff for a summer or two in blackwater while in college..
I sent her your picture and she said the same thing you just posted, ask UMD..
 
It looks like a sponge, hard to tell from just the photo. A sponge has calcium spicules which give it a somewhat hard, crumbly appearance, but they don't usually grow that fast.

Again, just a wild thought without seeing it.
 

Gilligan

#*! boat!
PREMO Member
It looks like a sponge, hard to tell from just the photo. A sponge has calcium spicules which give it a somewhat hard, crumbly appearance, but they don't usually grow that fast.

Again, just a wild thought without seeing it.

It definitely does look a lot like a sponge..but it's anything but "spongy". Quite crusty and brittle.
 

Gilligan

#*! boat!
PREMO Member
I wonder if a paint that sloughs faster would help.. like we had before.....

Trying a new-to-me paint this time...Petit's Ultima ECO. And..put it on the running gear this time too, instead of using that spray can prop and rudder antifouling stuff that never worked anyway. Previously, I've been using Interlux Pacifica, which I never got a full season out of. This year it was a toss up between the Petit Ultima ECO and the improved Pacifica Plus, both apparently using some new anti-shell ingredient. Both about $180 a gallon, so no difference there. The PITA of having an aluminum hull...paint options are very limited.

She's going back overboard in an hour or so..all nice and clean and almost ready for some weekend boating.
Marinette.jpg
 
Top