The Oysterbot: Developing a Ropeless Bottom Cage Retrieval System for Nearshore Oyster Farms

View the project final report

Commodities

• Animals: shellfish

Practices

• Animal Production: aquaculture

As more oyster farms are established in the northeast, the preferred intertidal and shallow subtidal areas will either be occupied or not available. Expansion of oyster farms will be forced into nearshore waters but will be limited due to entanglement risks from vertical lines to marine megafauna. Blue Stream Shellfish proposes to develop a means to retrieve ropeless oyster cages from waters >15’ deep using a remotely operated underwater vehicle (OysterBot). OysterBot will be designed based on identified criteria and constructed from off-the-shelf components. The ROV will be tested on a commercial nearshore oyster farm over the annual operations cycle with the handling characteristics of the system compared to handling a conventional cage with vertical lines to buoys. The OysterBot will be presented to farmers through publication, regular farmer gatherings, and demonstrated on interested farms.

This project seeks to build a technology that allows nearshore oyster cages on the bottom to be retrieved without vertical lines to surface buoys. This will be accomplished by developing a tethered remotely operated underwater vehicle (ROV) that will provide a real-time image of the cage on the bottom and will attach a lifting line to the cage for retrieval. The following objectives are proposed to complete this project:

1. Identify the mechanical attributes of an ROV required to achieve the goals of maneuverability underwater, identification of unique bottom cage markings, and ability to attach a lifting line to a cage harness for retrieval;
2. Design and construct an ROV that meets the qualifications outlined in Objective 1 (i.e. the OysterBot);
3. Evaluate the OysterBot on a commercial farm to assess its capacity to replace surface lines for cage retrieval;
4. Outreach this technology to other farms that are operating in nearshore waters.

The availability of the OysterBot concept will not only aid current subtidal farms in managing cage retrieval but it will also open up new areas for oyster farming by eliminating the vertical lines that will prohibit farm development where entanglements are a risk.