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> "Large accumulations of mussels can weigh as much as 1,700 pounds per square foot." I really find it hard to believe that is a number based in reality. Disc

> "Large accumulations of mussels can weigh as much as 1,700 pounds per square foot." I really find it hard to believe that is a number based in reality. Disclaimer: I am no expert! EDIT: Even if the mussels were solid gold and it was a cubic foot of them, they would "only" weigh 1206 pounds. source: http://www.coolmagnetman.com/magconda.htm http://www.coolmagnetman.com/magconda.htm

blacksmith_tb 9y ago
A little digging around suggests 35kg per square meter is a more reasonable estimate[1], which is about 8lbs per sqft. I suppose it's possible some measures include the weight of the water in the mussels, and others don't? 1: https://www.boatdesign.net/threads/boat-weight-increase-due-to-the-marine-growth.48041/ https://www.boatdesign.net/threads/boat-weight-increase-due-...
- Retric 9y ago
  That's ignoring the buoyancy from displacing water and only covers two years. I could see the worst case say a stationary house boat being vastly more problematic over 30+ years. But, they should generally fall off before the weight gets crazy.
mjlangiii 9y ago
I just assumed cubic feet
- kimolas 9y ago
  Even a cubic foot of water would be well under 100lbs. I doubt a cubic foot of mussels + water to fill the rest could weigh a ton. It may be possible for (especially stationary structures) to accumulate enormous columns of biofouling materials, but for such a layer to reach > 20 feet thick (possibly closer to 50 feet without counting the interstitial water) sounds unreasonable. But I'm not knowledgable in this area.
notatoad 9y ago
It does seem hard to believe, perhaps they mean a square foot of mussels on a boat bottom causes drag equivalent to towing an extra 1700lbs?
ChuckMcM 9y ago
I'm guessing it is a typo of some form. One (or perhaps both) of the unit values are wrong. It doesn't takeaway from the fact that mussels are a huge issue, or the amazing way they have adapted to attaching themselves to surfaces.
pishpash 9y ago
Find a way to harvest the mussels and you'll need no food delivery at sea. /s
dguaraglia 9y ago
I wonder if the author is confusing weight with drag. I could see mussels (and the algae they always bring with them) introducing more drag on the hull than their weight. But then again, I'm no expert, just a weekend sailor.
jandrese 9y ago
I had a mental image of a foot square patch of hull with a 200m long spire of mussels sticking off the side. I'm pretty sure that's a typo in the article.
- gozur88 9y ago
  "It's weird. The chart says depth here is 200m, but we always bottom out." Yeah, that's just a crazy number. It would be a crazy number if mussels were made of lead.
clort 9y ago
perhaps the square foot is only the footprint of the accumulation of mussels? They could extend out a pretty long way..

blacksmith_tb 9y ago

A little digging around suggests 35kg per square meter is a more reasonable estimate[1], which is about 8lbs per sqft. I suppose it's possible some measures include the weight of the water in the mussels, and others don't? 1: https://www.boatdesign.net/threads/boat-weight-increase-due-to-the-marine-growth.48041/ https://www.boatdesign.net/threads/boat-weight-increase-due-...

Retric 9y ago
That's ignoring the buoyancy from displacing water and only covers two years. I could see the worst case say a stationary house boat being vastly more problematic over 30+ years. But, they should generally fall off before the weight gets crazy.

mjlangiii 9y ago

I just assumed cubic feet

kimolas 9y ago
Even a cubic foot of water would be well under 100lbs. I doubt a cubic foot of mussels + water to fill the rest could weigh a ton. It may be possible for (especially stationary structures) to accumulate enormous columns of biofouling materials, but for such a layer to reach > 20 feet thick (possibly closer to 50 feet without counting the interstitial water) sounds unreasonable. But I'm not knowledgable in this area.

notatoad 9y ago

It does seem hard to believe, perhaps they mean a square foot of mussels on a boat bottom causes drag equivalent to towing an extra 1700lbs?

ChuckMcM 9y ago

I'm guessing it is a typo of some form. One (or perhaps both) of the unit values are wrong. It doesn't takeaway from the fact that mussels are a huge issue, or the amazing way they have adapted to attaching themselves to surfaces.

pishpash 9y ago

Find a way to harvest the mussels and you'll need no food delivery at sea. /s

dguaraglia 9y ago

I wonder if the author is confusing weight with drag. I could see mussels (and the algae they always bring with them) introducing more drag on the hull than their weight. But then again, I'm no expert, just a weekend sailor.

jandrese 9y ago

I had a mental image of a foot square patch of hull with a 200m long spire of mussels sticking off the side. I'm pretty sure that's a typo in the article.

gozur88 9y ago
"It's weird. The chart says depth here is 200m, but we always bottom out." Yeah, that's just a crazy number. It would be a crazy number if mussels were made of lead.

clort 9y ago

perhaps the square foot is only the footprint of the accumulation of mussels? They could extend out a pretty long way..