Teredo Worm

Not on my boat, luckily.

The Teredo worm (shipworm)has been the bane of wooden ships, boats, pilings and retaining walls since man has ventured to the sea. A type of clam, the Teredo worm has two shells, enclosing only the front end of the body which function as a tool rather than a protective covering – they are a boring clam. Each shell has toothed ridges which shave away bits of wood into smaller pieces and then those are ingested.

Teredo worms have been known to achieve a length of up to 2 ft long, although the shells remain only about a foot long. The British and Spanish navies estimated that a wooden hull in the Carribean in the age of sail would last ten years.

Mariners as early as 500 BC tried to protect their wooden ships by various combinations of arsenic, sulfur, tars and oils. The British Navy experimented with a sacrificial covering of wood covering tar, but it wasn’t successful. It wasn’t until the invention of copper hull plating that the Teredo worm became less of a problem.

I was under the impression that they were more of a problem in warmer waters than we have in the Pacific NW. But apparently they’ve damaged seawalls around here and gnawed on some boats. Yeesh…

No Responses to “Teredo Worm”

  1. Anonymous
    June 24, 2010 at 1:14 pm #

    I am not going to be original this time, so all I am going to say that your blog rocks, sad that I don't have suck a writing skills

  2. rob
    February 7, 2009 at 7:48 am #

    Surely the water is too cold if not barely brackish???? but Keep an eye on the pontoons and walls to seaward around your dock, as that will be an indication of what is happening to your hull maybe? :o(( if you have any doubts, start collecting thick walled,scrap copper household calorifiers to copper plate your hull! and learn how to create plates and how to fold them togeather, although I am not a fan of trapping water in between the hull and such plating! it is a good way to protect your hull both from such booring menaces and other crustacean/weed fouling. I guess that the local harbour facility keeps in touch with the state of play regarding such pollution (after all that is what it is isn`t it?) may be the local harbour/education/sciences faculty are aware of any shipworm ingress into the channel and to what extent it is? Ive seen the photos of pilings in the BC area but they weren`t andtifouled, I guess unlike the average boat, or treated with epoxy pitch or such like substance? What a PITA?