18 September 2009

Reef Balls

In Jessee's post Goodbye Summer 2009, she mentioned one of the service projects that SFS is involved in: Reef Ball building. For some time, SFS has been making concrete structures to create an artificial reef. Today, we deployed the first batch.

We picked a nice sandy patch down the way from Shark Alley and heaved them overboard. That wasn't until after all of the heavy lifting was finished though. We had to carry them about 100 yards from where we built them, down two sets of stairs, over the dock, and onto the boat. And they must weigh in the range of 300 pounds! The heaviest one took 5 people to move. The stairs were probably the trickiest part. At one point I actually got knocked off the dock into the water. As we were straining to get the ball down the first flight of steps the group wanted to rest, so they started to set it down. But, unfortunately, they didn't give me much warning and one of the boards we were using to carry it was being placed onto my foot. I pulled back to get it out before it was crushed, and when it came free I was knocked off balance. It was very slow coming, but I couldn't keep from going over the edge. It was all pretty funny and I think I started laughing before I even hit the water.

Once the balls were in the water we went down on SCUBA and used "lift bags" to move them into the correct place. A lift bag is a specially designed bag that you anchor to a heavy object underwater and then fill with air from your tank. The air provides bouyancy and lifts the object upwards. We only had two bags for a total of 150 lbs of lift, but it was enough to lighten the load so we could easily push them into place (the water displaced by the ball itself made them considerably lighter to begin with).

The next step will be to transplant corals to get the colonization process started. Fish and crustaceans will quickly move in on thier own (in fact some have probably already found them), but corals take much more time, so we will help them along. We'll go looking for small fragments of coral (or collect some if need be) and then attachment to the ball using a special marine cement. With just a few pieces, they should take hold and grow all over the ball.

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