Drakes Bay Oyster Company is Granted an Injunction

Drakes Estero is Not

Invasive Tunicates on DBOC oysters

will continue to be spread in Drakes Estero.

(click to enlarge)

(Heidi Schumann for The New York Times)

 

The 9th Circuit Court of Appeals has granted Drakes Bay Oyster Company (DBOC) an emergency injunction allowing it to continue commercial operations until May. How the California Coastal Commission acts on its separate cease and desist order remains unknown.

 

What is known is DBOC's commercial operation is allowed to continue to spread the invasive Didemnum vexillum tunicate throughout its 1,000 acres of operation in Drakes Estero and beyond. Colonies growing on DBOC's non-native oysters break loose when harvested and float freely for weeks throughout Drakes Estero until settling onto a suitable substrate, whether they be native shellfish, or the non-native Pacific oysters grown (as seen in the picture above) or any other suitable substrate. This issue was of special concern in the recent cease and desist order issued by the California Coastal Commission.

 

It was weakly argued before the California Coastal Commission that Dv "is everywhere." What is not everywhere is the surface area for it to attach to and grow. More importantly is the movement of colonies throughout Drakes Estero which this commercial operation, and others like it, provide. National seashore or not, commercial shellfish operators do not currently believe their activities make a difference in the growth and spread of Dv. They do and it is significant, whether in Drakes Estero, Puget Sound, British Columbia or elsewhere.

 

Dv growth on aquaculture gear

in Okeover Inlet, British Columbia.

 

Dv growth on Taylor Shellfish mussels

in Totten Inlet, Puget Sound

 

Dv spreading on subtidal areas of Georges Bank

 

 

 

Didemnum vexillum colonies alter marine habitats and threaten to interfere with fishing, aquaculture, and other coastal and offshore activities. The colonies shown here [seen above]  are found on hard substrates that include dock structures and floats, wood and metal pilings, moorings and ropes, steel chain, automobile tires, polythene plastic, rock outcrops, gravel seabed (pebbles, cobbles, boulders), and ship hulls. They overgrow organisms such as tunicates, sponges, macroalgae, hydroids, anemones, bryozoans, scallops, mussels, and oysters. Where these colonies occur on the seabed, they likely cover the siphons of infaunal bivalves and also serve as a barrier between demersal fish and benthic prey. The colonies have been found at water depths ranging from intertidal to continental shelf depths of 65m (213 ft).