Daily Journal

June 15, 2010

By David M. Lawrence

Yesterday I served on midwatch, which began at 2300 hours. After running on diesel for a couple of days because of the calm winds, we switched to sail shortly after midwatch started. I was posted to bow watch – the ships lookout during periods of low visibility such as nighttime – so wasn't involved in raising the sails.

First, the engine was shut down, sails were set, and the wind took care of the rest. We've been making six knots or more since then.

Now that we've switched back to sail, we aren't sampling quite as much, but the science program continues and we add more to it. Chief scientist Giora Proskurowski and SEA volunteer Emelia DeForce have begun analyzing the microbial life found upon the plastic debris. Among the questions they are trying to answer are whether the microorganisms break down the plastic, use it as a substrate to attach to, and whether different types of microbes inhabit different types of plastic.

In addition to beginning the microbial research, Proskurowski began collecting data to test whether turbulence at the surface – such as that caused by wind-driven waves or swell – mix plastic particles from the surface deeper into the water column. Samples to be used to test this hypothesis are collected in a fashion similar to the neuston net tows at the surface. In this case, they are using Tucker trawl tows. A Tucker trawl tow uses a weighted net to collect samples at a discrete depth. They also deployed the carousel to measure water characteristics beneath the surface.

We had a wide range of topics presented during class time today. Assistant engineer Sarah Lake discussed how the pumps on the heads (bathrooms) work. One cannot underestimate the importance of such a discussion to a ship's company of 33 committed to nonstop service on a 134-foot brigantine for 34 days. During the navigation segment, SEA volunteer Jacob Keaton – whose day job is as a science writer for NASA – gave us fixes on our distance from the sun and from the center of the galaxy (the latter will require a lot of sailing time to reach at a speed of six knots). The weather segment updated us on the low pressure system that has given us the wind we have enjoyed today. For the final portion of class time, Captain Chris McGuire presented a primer on celestial navigation.

In the meantime, the SSV Corwith Cramer continues pushing eastward.