Echos of life under the sea

Hi everyone! My name is Haley Glasmann and I am a second year PhD student in Dr. Kevin Boswell’s Marine Ecology and Acoustics Laboratory at Florida International University. I am very excited to be here on the R/V Point Sur on my first ever scientific research cruise. Dr. Boswell’s lab focuses on using active acoustic a.k.a. SONAR (Sound Navigation and Ranging) technology to understand the processes that mediate behavioral and distributional patterns in marine organisms.

As part of the DP08 cruise, we are using ship-mounted echosounders to observe the deep scattering layer community. The “Pod” is where we have echosounders operating at frequencies of 18, 38, 70, 120, and 200 kHz. Having multiple frequencies helps us characterize the water column based on the acoustic response (echo) of individuals and/or the aggregations that are dispersed under the pod during data collection. This data is shown to us in real time, which allows us to inform where to deploy our WBAT (Wideband Autonomous Transceiver) and MOCNESS (Multiple Open/Closing Net and Environmental Sensing System). The WBAT (that we affectionally also call the “wombat”) is currently fitted with a 38 and 200 kHz transducer operating in wideband and is mounted to the CTD (Conductivity, Temperature, and Depth) profiler, which travels through the water column down to depths of 1500m. With the ability to bring the WBAT/CTD into the scattering layers themselves, we can collect high resolution data on the individual scattering types (organisms) present within. For my dissertation, I am interested in using the WBAT data in tandem with the ship-mounted echosounders to analyze the spatial arrangement and density of scatters within different parts of the layer. Fine scale interpretation of the community that undergoes diel vertical migration has important implications for developing an enhanced understanding of carbon cycling in the open ocean and mesopelagic fisheries management

The acoustics lab and Haley deploying a CTD array (Photos: Haley Glasmann)

A typical “day” on the R/V Point Sur for me begins at about 4:30pm, let’s hear it for the night shift! First order of business is programing the WBAT for deployment on an evening CTD cast. I then eat dinner for my “breakfast” while the unit is collecting data. At about 8:45pm, we retrieve the CTD/WBAT back on deck and then the crew prepares to deploy the MOCNESS. During the night I monitor the ship-mounted echosounders, keeping a close eye on computer processing and power supply to ensure we are continuously collecting data. Other parts of the night include catching up on reading, replying to emails, jamming out to my Spotify playlists, making Styrofoam crafts (check out my shrunken head!) and the best part of all- seeing all the deep-sea creatures that come up in the MOCNESS around 3am. As the sun rises, I prepare to end my day with another CTD/WBAT deployment and enjoy a savory breakfast of bacon, grits, and biscuits from Chef Mike! …and after that at about 9am, time to get some rest!

Styrofoam head before and after CTD deployment down to 1000 m (Photos: H. Glasmann)

Check out my video on Instagram https://www.instagram.com/reel/Cg0jjLEFspY/?igshid=YmMyMTA2M2Y=

Interested in keeping up of my graduate school adventures and the Boswell Lab? Check out @scubahaleykat and @boswelllab on Instagram for more!

Thanks for reading!

Best fishes,

Haley K. Glasmann