A Day in the Life of a Marine Researcher: August 4th, 2023 - Exploring the Depths of Bonne Bay

By Sydney, Plastics and Marine Conservation Coordinator at Atlantic Healthy Oceans Initiative (AHOI) As the sun was shining in Bonne Bay, the AHOI team set off for another exciting day on the water. This day offered an opportunity to explore and contribute to conservation efforts in the eastern arm's deepest depths.

Morning on the Southeastern Arm

The day started with clear skies and a gentle breeze, the perfect day to conduct our marine research work. Our first task was to retrieve green crab traps deployed the day before in the southeastern arm. We removed the traps from the water, documenting the green crabs inside. Each specimen was counted, measured for carapace length, sex recorded, and then removed from the environment in an effort to reduce the Aquatic Invasive Species population in our region.

Our journey continued as we made our way back along the eastern arm, stopping at areas with eelgrass beds. Here, we retrieved more green crab traps and deployed our Remotely Operated Vehicle (ROV) to conduct preliminary assessments on the health of these eelgrass beds.

Diving into the Aphotic Zone: The Deepest Point of the Eastern Arm

As the wind dropped out, we took the opportunity to drop our ROV to the deepest point of the eastern arm, 225 metres or 730 feet! Our team worked diligently—Aaron piloted the ROV, Daniel managed the tether, Rebecca kept the boat steady, and I observed for any potential obstacles.

The descent to the bottom took about five minutes, and as the ROV reached the aphotic zone, Aaron illuminated the pitch-dark surroundings using the lights equipped on the ROV, revealing a world teeming with life.

A video from the ROV as it lands near the bottom of the ocean floor at 221 m depth.

A Look into the Depths

The environment was much different than the ones we usually see using our ROV—complete darkness, a sandy/silty bottom, and marine snow, falling detritus from the water column above, delivering essential nutrients to the ocean floor. The 0-degree water temperature was ___ than the 10-degree temperature measured at the surface before descent. 

We observed translucent organisms adapted to the absence of light. Shrimp, zooplankton, and jellyfish species moved through the water, revealing a hidden ecosystem thriving in the depths of Bonne Bay.

A short video from the ROV displaying some of the marine life we encountered during the ROV dive.

Beyond the Depths

Our journey to seeing the bottom of the eastern arm only marked the beginning of exploring the depths of Bonne Bay. Using our ROV, AHOI plans to continue to assess the marine environments of Bonne Bay and other marine regions of Gros Morne. Each dive allows us to better understand how connected our marine environments are, reinforcing our commitment to protecting the health of our ocean for generations to come!