This video from the USA says about itself:
Rockfish recorded with the Benthic Observatory System
24 May 2018
Over 90 species of rockfish are caught commercially off the West Coast of the United States, but some deep-water species have been severely affected by overfishing. To help these threatened populations recover, fisheries scientists need to know how many fish are out there and how large they are, so they can regulate where and how many fish can be caught each year. As part of this effort, MBARI recently partnered with The Nature Conservancy, Moss Landing Marine Laboratories, and other organizations to design a new camera system for counting threatened rockfish off the US West Coast.
For more information, see the Monterey Bay Aquarium Research Institute (MBARI) 2017 Annual Report.
See also here.