The MOBY Tag: A minimally invasive, intermediate-term, camera-equipped data tag for cetacean research.

Columbia University, 2023-2024

My Role

Product Manager & Lead Mechanical Engineer.

The MOBY tag was developed as part of a year-long senior design project at Columbia University.

Tools
- 3D Printer
- Laser Cutter
- Wind Tunnel Testing
- Waterproofing

Software
- SOLIDWORKS
- Blender
- Keyshot
- Raspberry Pi/Arduino

Project Deliverables
- Heavy Duty Remora Suction
- Current-Aligning Housing
- Turbine Energy Generation
- Environmental Sensing, Video Feed, Tag-Researcher Comms
- UX Flow
- User Feedback

- Presentation Poster

Project Goal/Overview

Team MOBY is seeking to better document whale behavior and migration with a novel marine tag. Tagging whales gives us information on their lives and how to protect them.

The problem with today’s tags? They’re wildly invasive. Harpoon tags can wound whales, causing life-threatening infection.

Newer, minimally-invasive suction tags don’t last longer than a day.

We needed to build a tag that was long-lasting and minimally invasive, while being equipped with camera and sensor technology that could give researchers new ways to understand life underwater.

Remora Suction Cups

The primary barrier to longevity for minimally-invasive marine tags is poor suction. Tags fall off whales after between 6 and 24 hours. In response, we designed our own heavy-duty remora-inspired suction cups.

When compared to standard suction cups, ours consistently withstood more instantaneous force.

*Remoras are a type of fish that use their suction-y dorsal fins to stick to sharks and whales!*

Current-Aligning Housing

Visual data is more important than ever in cetacean research. Unfortunately, existing camera tags cannot guarantee POV-style marine video. If they’re oriented incorrectly upon deployment, the video they capture isn’t super useful.

The MOBY Tag is self aligning. Even if it’s placed 180° from forward, it will right itself using the current induced by the whale’s movement (Like how a car’s movement generates “wind” you feel when you roll the window down).

We tested current-alignment in a wind tunnel and in a fluid dynamics simulation. Statistical analysis told us to manufacture a housing with a large fin and wide body.

Turbine Energy Generation

Remora suction cups ensure that MOBY will stay on a whale for the entire duration of any research project.

If suction is lasting for a long time, it follows that the electronics need to last for a long time as well. To respond to this need, we designed a turbine-based energy regeneration system.

As long as the whale is moving around 5m/s (their coasting speed), all our electronics will be recharged.

Many researchers we surveyed asked if we could collect data on whale speed! With the on-board turbine, we can do this. By comparing instantaneous current data with a characteristic curve, we’ll know exactly how fast the whale is moving.

Electronics

The MOBY electronics consist of a Raspberry Pi 4B equipped with a senseHAT module and a 120° underwater camera. The electronics housing is fully watertight according to NEMA standards and is depth-rated.

Sensors:
- Speed (via turbine current generation)
- Temperature
- Gyroscope
- Depth/Pressure
- Video
- Light

User Experience (UX)

The MOBY experience begins on our website, where researchers let us know exactly what data they’re looking to collect. Once researchers receive the tag in the mail, they can charge it and test if the camera and sensors are working.

Once the project launches, the MOBY tag can be deployed via boom or drone. Either way, it’ll stick!

Over the next two months, the tag will store data in internal storage. If the researchers want data in the interim, MOBY will send daily data updates to the online portal. When the tag detaches from the whale, it’ll stop collecting data and will ping the researchers with its GPS location until it’s picked up.

User Feedback

Throughout the project, we prioritized user feedback to ensure project work remained user-driven. The following survey is one example of this prioritization.

Goal:
Select an initial concept to bring to the prototyping stage.

Users/Survey Responders:
10 Industry experts and active marine researchers.

Desired Feedback:
- Which concept feels the most usable?
- Are there any features we’re overlooking?
- Do the innovations we find useful in the lab make sense in the field?

Insights:
- Use our turbine’s current reading to extrapolate instantaneous whale speed.
- A tag with satellite arms does not feel usable.

Questions about MOBY? Email ss6169@columbia.edu.

Acknowledgements
-Dr. Yevgeniy Yesilevskiy, Columbia University
- Prof. Kristin Myers, Columbia University
- Dave Cade, Stanford University
- Chris Zadra, Ocean Alliance
- Leigh Torres, Oregon State University
- Mauricio Cantor, Oregon State University
- Monica Ross, Clearwater Marine Aquarium
- Christy Hudak, Center for Coastal Studies
- Charles “Stormy” Mayo, Center for Coastal Studies

Team
- Sanjana Subramanian
- Ben Felson
- Jake Tivey
- Kristine Do
- Tiffany Qian