Innovative technology to monitor offshore mussel farm

Phil Cruver has ambitious plans for his farm. Catalina Sea Ranch LLC is a 100-acre site about six miles off the shores of Huntingdon Beach, California. It will feature 40 longlines growing up to 2.5 million pounds of Mediterranean mussels a year. And that’s only the beginning. In time Cruver plans to add rock scallops and sea cucumbers.

         For now though, the site is under construction on the San Pedro Shelf, a fairly shallow area of seabed with a muddy substrate. Mussel lines will be suspended about 150 feet below the surface. And Cruver hopes that it won’t be long before he’ll be harvesting his first mussels.

          Monitoring the offshore site has its own set of challenges and this is where a network of wireless technology put together in an agreement with the huge Verizon Wireless Corporation comes in.

         Coastal Commission approval – one of numerous approvals Cruver had to obtain from more than a dozen permitting agencies – came with a lengthy set of conditions and requirements for “intensive monitoring,” says Cruver. So the unit will use advanced buoy-borne monitoring technology that will transmit water-condition parameters and other data to company personnel on shore, using the Internet and Verizon’s cellular network.

         That’s just the start when it comes to the monitoring, security and surveillance technology.

         The National Oceanic and Atmospheric Administration (NOAA) is supplying a boat-shaped NOMAD buoy that measures 20 feet long and 10 feet wide and stands some seven feet above the waterline. The buoy will gather and transmit the bathymetric data such as water temperature, salinity, and pH, as well as vital phytoplankton density.

         The NOMAD buoy will have a radar system to provide ranch security, and the site’s perimeter buoys will have underwater acoustic cameras to detect seals and sea lions. The NOMAD buoy will have railings to prevent them from coming aboard.

         The buoy also has wind, weather, rainfall and wave sensors as well as four 100-watt photovoltaic solar panels attached to a battery pack below decks, a self-contained light that will be visible for six nautical miles, and a winch to raise and lower the water-quality sonde. The detector has six replaceable sensors, as well as a central wiper to clean off any bio-fouling.

         The site will have a number of Remotely Operated Vehicles (ROVs) to inspect the infrastructure and collect scientific data, including a mini-ROV (weighing just 10 lbs) attached to a 150-foot cable, that will inspect the shellfish. To be operated remotely from a boat, the mini-ROV is just 19 ins long and 14.6 ins wide and has its own LED lights and internal and external LED cameras.

– Quentin Dodd