August 11, 2006 - Deploying Traps Options

[Maggie_Kane]

Today was a very important day for Heidi’s project. I decided to stay and help with the boat even though it was very cold and wet work. It was really interesting to see how the sediment traps are put together and deployed and I wanted to be able to show you. You saw a few days ago how the traps are pulled up, and what the sediment looks like in the narrow plastic tubes. We will keep last years tubes and Heidi will extract the water, dry them out and take them back to college with her to analyze. In order to set up new tubes to collect sediment for this coming year, we need to construct new traps. We can use the funnels and grates from last year, and cut new tubes.

Cleaning The Funnels


We cut the tubes, put a rubber stopper in the bottom and wrapped it with electrical tape to keep it secure.

Readying Tubes


Then we labeled the tubes with sharpie. There are 5 different moorings in different parts of the lake that we were going to set up. Each one has a letter name. We were working with mooring C, D, E, F and G. Each tube would be labeled with the mooring letter and a number.

Labeling the Tubes


C1 would be for the trap closets to the surface at mooring C, C2 would be lower on the rope at the same mooring, etc. Some of the moorings are in deeper water than others so those ropes would be longer and have more filter traps than the shallower ones.

Mooring C-G Laid Out


We had to be careful to get everything well organized before we went out on the water. We had to measure the depth each filter would go onto the mooring line. Then we would tease a plastic cable tie through the tightly twisted rope. Once on the water in the right spot, we would attach the filter tube and funnel to the cable ties.

Stringing Out the Mooring Lines


Once we were ready to go out with a few mooring lines, we loaded the big rock anchors onto the boom of the boat, coiled up the lines and arranged the traps in the boat.

Rock Anchors


Then we went to find the mooring markers on the lake. Once we found the floating marker buoys, we used the GPS to get us as close as possible to the exact spot that they have gone into every year. Remember that boats drift in the wind, and staying in one place is nearly impossible!

Finding Mooring F (Firklover is a kind of chocolate bar we like to eat!)


Using the winch on the boom, we slowly let down the anchor so that the spot for the filter trap (we knew where by the cable ties we placed) was just below the boom. Then the fun part started!

F3 (the lowest one at F) and Rock Anchor


Heidi had to lean way out over the side of the boat to attach the filter trap. I made sure that she didn’t get too far out because the water is extremely cold and a spill into it would be very serious. Once that was attached, she also attached a temperature logger to the line so that next year’s group could see what temperature the water was at each collection site. We think that temperature has a lot to do with the water column and how the sediment moves through the lake.

Very Cold Work


Then it was onto F2 and then F1 to complete the traps. Then we set a buoy on top to hold the line taught in the water. This is really important so that the line doesn’t flounder and droop in the water. We would not allow the buoy to bob above the surface, however. This is because the surface of the water will freeze solid.

Deploying the Buoy…


…To The Surface…


…And Just Below for the Winter!


We all had gotten really chilled working in the water all day. It took about 20 minutes of strenuous hiking to get us feeling OK again. I probably never mentioned what the first part of our hike is like once we leave the boats and start heading home. There is a hill that comes right out of the water at the boat launch that is very steep. It is the first 5-8 minutes of our hike. It is nearly a 45 degree slope and even steeper than that at the tip! I don’t look up, and just keep putting one foot in front of another! I am always the last one up, but it has gotten a lot easier as I have gotten stronger. It gets us warm which is good after a boat ride, but it is really hard on our tired bodies. A hot dinner and some tea helps too when we got back to the station.