I spent this past week on Cape Cod coordinating the retrieval and redeployment of the Noise Reference Station mooring in Stellwagen Bank National Marine Sanctuary. Last October we deployed the hydrophone (NRS09) for the first time at our long-term site, and this year we were faced with the challenge of retrieving a 700 lb mooring without any surface expression. Luckily, we had a great weather day and the process went off without a hitch!
As soon as we brought the lander back on board we got to work cleaning on the (small amount of) biofouling that accumulated over the past year. I also needed the prepare the acoustic release for re-deployment. In order to retrieve a mooring without any surface expression, we needed a system that would allow us to pull up the lander from the ocean floor; an acoustic release is the perfect solution. To make the re-deployment process easier, NRS09 was designed to use a release that can be easily re-assembled and re-used for successive deployments. Below I am taking release mechanism out of the housing to replace the battery.
Once we had the lander on board we swapped out the hydrophone and prepared the lander for re-deployment. We had to be very careful to secure any pieces that could create noise (and interfere with the ocean noise we are trying to record).
Once the lander was cleaned, acoustic release re-assembled, and new hydrophone secured we were ready to re-deploy NRS09 in Stellwagen Bank National Marine Sanctuary for another year.