Tuesday, April 14, 2015

Back in business

When I went out on the boat last week, I was shocked to find that two of my moorings were still there, even though they had been left out in a stormy ocean over the winter. I was hoping that I could reuse the cement blocks this summer and save myself a little work, but it doesn't look like that's possible. The cement was crumbling, and the bolts were rusted to the point of being useless. 

Enter Plan B. I spent some time at the end of last week gathering supplies, and I managed to build 10 brand-new cement moorings over the weekend. It took a little while, but we're back in business.

Cement blocks drying in their wooden molds.
To make the moorings, I bought bags of ready-mix cement. The mix is a combination of gravel and a dust-like powder that becomes viscous when added to water and dries in about a day. The bags are heavy, about 90 lb each, so I had to ask for help loading them into and out of OIMB's pickup truck. Thankfully, the guys that work in the OIMB shop are almost always willing to help, because I pay them in baked goods. Carrying 15 heavy bags of cement mix from a truck bed into the workshop? That's about a dozen cookies. 

When it came to mixing and pouring the cement, though, I was on my own. The guys set me up with a cement mixer and a scoop, so I didn't have to do any heavy lifting. Granted, it took me a lot longer to empty a bag of cement mix by scoop than by just pouring it into the mixer, but the lower risk to my vertebral discs was worth it. I dug my wooden molds from last year out of the warehouse and set to work. The molds are simple wooden boxes with two holes in each side for embedding bolts. Those bolts will eventually hold my settlement plates onto the cement block, so I need them to protrude. I also embedded an eyebolt in the top of each block so a rope can be attached. Once the cement was dry, I removed the screws from the wooden mold and disassembled it to reveal the finished mooring inside.
What's 300' of rope look like? It stretches
all the way across campus.

While I waited for the cement to dry, my next step was cutting rope. The moorings will be outplanted at about 200' (65 m) depth, so I cut 300' sections to make sure I had plenty of slack. Rope can get tangled in the water or swept to the side by a strong current. Actually, there was one instance last summer when the current was so strong that the ropes ended up diagonal in the water column instead of vertical, and the floats at the top were dragged about 15' below the surface of the water. I was already in Norway at the time, but the volunteers who went out that day found it incredibly frustrating to see but not be able to grab the floats. I want to make sure that doesn't happen again. 

Finally, I took a few hours to clean and label my settlement plates. The plates are 6" squares of plexiglass that will hopefully be substrata for recruiting larvae. One will be attached to each bolt on my moorings - 80 plates altogether. I was thankful to find I had enough plates pre-cut and left over from last year that all I had to do was label them. At least one thing was easy!

It took a few days, but I now have all the parts and pieces in order for my experiment. The weather has been pretty bad this week, with strong waves and high-amplitude swell offshore. I'm waiting for it to calm down, but once it does, I will load everything onto the boat and go deploy my moorings offshore. We're almost there!

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