The BlueBoat Listens to the Sounds of the Ocean

This week we took one additional field sampling trip since we had to stop our final sampling trip early last week due to boat issues. Across these four trips, however, we learned a lot about how all the marine technology works, ways that we can improve the sampling process, and some alternative strategies for our next trips, which we will make in a few months. Tomorrow I will be bringing all of our processed samples to our collaborator who will work to analyze the water and sediment we collected. Our USM-based colleagues will then use these data to inform their biogeochemical and sediment transport models, which inform the ecosystem model on which Kim and I work. My next steps, likely starting Monday, are to process the data. Here, I need to work across three different types of data we collected in the field and my goal is to create an end product that links the three data components together. When we pilot the BlueBoat, we have a time that the boat starts moving, a fixed path it takes through the water with an end point, and a time the boat stops its path. We also have a set travel speed for every deployment. What I do not know is whether the boat logs its GPS coordinates and time stamps them so that I can track its exact position every minute it is moving. With the start time, end time, and the speed, however, I can determine the approximate location of the boat at every minute of its path, which is useful for the other data points. The water quality sampler and the nitrate sensor both record time-stamped data every minute they are receiving power. Therefore, if I know the location of the boat, I can plot the water quality and nitrate data points in geographic space, which further helps our physical modeling team. Perhaps one side of the river channel gets more flow than the other or there are higher nutrient loads in the middle than on the sides. These are valuable pieces of information for our team, and I will spend a few days starting to put these items together. 

Now, regarding the title of today's blog, there's one piece of data that the BlueBoat collects that I have not talked about. We outfitted the BlueBoat with a ping echosounder, which is a device that sends out ultrasonic pulses or pings and listens for the echo to bounce back. From these pings and echos, the BlueBoat generates an image of the seafloor and determines the depth of the water column. In today's picture you can see that the water column was 1.99 m or approximately 6.5 feet at the point of the ping. Even from this data set that looks rough, a scientist can take some additional information and make a three-dimensional image of the seafloor, and what I really like is that the BlueBoat and this echosounder are not outlandishly expensive items, making some aspects of this research feasible on a tight budget. I am not sure if we will use the echosounder data yet, except to possibly answer questions about the water quality data set if there are trends that may be supported by differences in depth, but I enjoy seeing the variety of information we can collect by putting our boat in the water, connecting it to the computer and software, and piloting it across a small body of water.

That's all for this week. There will not be blogs for the next two weeks, as I will be away, so stay tuned for the next blog scheduled for January 8th. Happy Holidays, everyone.

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