The BlueBoat Hits the Open Water

Hannah fearlessly holding on to the BlueBoat lead and nitrate sensor cable while it completes a horizontal transect across Biloxi Bay and avoids an array of crab traps.

This week we embarked on two (soon to be three) field expeditions to start our water quality sampling project. We spent Tuesday and Wednesday sampling across Mobile Bay, Alabama, and the Pascagoula River and Biloxi Bay in Mississippi. Tomorrow we set sail for portions of the western Mississippi Sound and expect to sample in four distinct locations. The purpose of these field excursions is to collect water quality data through a horizontal transect and a vertical profile. The BlueBoat automatically cruises on site to collect nitrate, salinity, temperature, dissolved oxygen, and some additional parameters from the surface water. Then, we sail to the center of the horizontal transect and use our water quality sensor to collect similar measurements starting at the water surface and moving slowly toward the seafloor. Along with the vertical water quality sensor deployments, we collect water samples during the vertical profile for nutrient analysis. The nutrient analysis process involves filtering the water samples to collect any suspended sediments, then filtering the water through a very fine filter to remove as much bacteria and microscopic organisms as possible to prevent ongoing decomposition of the nutrients in the water. We freeze the samples and then ship them to a colleague's lab where he will conduct the rest of the nutrient analysis processing. 

We encounter a few challenges during the first field day, as the boat ran out of power because the batteries had drained over the weekend and I didn't realize. Day two, however, went much smoother and the BlueBoat even managed to avoid an array of crab traps during its longer transect route. We also successfully collected nitrate data from the transects, which is a big win since this was our first time testing out the capabilities of the nitrate sensor.

Tomorrow, we set out on our final sampling day for our December trips, where we will sample four locations-one large bay mouth and three smaller river mouths. While we will need approximately one hour to complete the bay transect, we will only need ten to fifteen minutes per river. However, these times are nothing compared to the four hour transect in Mobile Bay. Additionally, tomorrow we expect the best weather we have had all week, with temperatures in the low 70s. This compared to the 40 degree weather during the four hour transect. A big thank you to the teams who have assisted with this field work and to those who have contributed their pictures. Since I haven't found time to train others on programming and using the automatic functions of the BlueBoat, I need to sit in front of the computer controls during the field work and don't have much time to snap pictures.

​Stay tuned next week for more updates from the De Mutsert lab and our field adventures.

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