Ah, Louisiana. Famous for seafood dishes including shrimp étouffée, oyster po’boys and blackened redfish. Although some of you reading may now be thinking of lunch, there are some great stories behind the recipes, and the efforts people make to secure your meal’s ingredients now and in the future.
One of those people is Dr. John Supan, the Louisiana Sea Grant Oyster Research Laboratory Director who oversees a new oyster hatchery on Grand Isle that provides the larvae, or “seed”, for shellfish farmers and oyster reef rehabilitation efforts. We recently asked him some questions about how this hatchery helps ensure coastal areas are resilient not only for Louisiana’s culinary history, but also for the regional ecosystem.
Oysters provide a number of services to the natural environment. They improve water quality by filtering water as they feed, help prevent coastal erosion, and also provide habitat for fish and other species. However, oysters and the people that grow them face a number of threats.
Ocean acidification endangers oyster production around the country, and the shellfish aquaculture industry is leading the charge to raise awareness of this threat. A result of a combination of carbon pollution and nitrogen runoff pollution from urban and rural areas, acidification causes oyster larvae shells to weaken, decreasing their survival.
Also, newly released data show between 4 and 8.3 billion oysters are estimated to have been lost as a result of the BP Deepwater Horizon oil disaster in 2010. These impacts, combined with ongoing impacts such as drought, floods, coastal development and hurricanes, make for a tough road for oysters. The good news is that there are things we can do to protect oysters and the people that grow them, and we talked to John to learn more:
Ocean Conservancy: How did you get started with oysters, and what do you enjoy about it?
Dr. John Supan: During my master’s degree pursuit in the late 1970’s, I worked at a pilot oyster hatchery at the Gulf Coast Research Laboratory in Biloxi, MS. There, I learned about breeding, rearing and maintaining oysters. I also learned to build things, plumbing and wiring systems to support growing aquatic organisms which appeals to my “blue collar” background. I most enjoy the daily sense of accomplishment—seeing things growing due to your work, as opposed to staring at a computer screen.
OC: Earlier this year, the oyster hatchery you direct was rebuilt and reopened. Can you explain why this occurred, what’s new and what is its purpose?
JS: It’s been said that every storm cloud has a silver lining. Hurricane Katrina wiped out our old facility, and due to the recent availability of funds, I began designing a new hatchery that could address the 26 years of problems I encountered while running a hatchery on Grand Isle. Molluscan shellfish hatcheries and the larvae they raise are very vulnerable to poor water quality, so the new hatchery included features to address this.
The old hatchery was operated seasonally (May-September) because it was outdoors under a shed or building, so we could not heat and maintain hatchery seawater temperature. That stymied algae and shellfish larval growth, increasing the likelihood of problems, so moving hatchery operations indoors with seawater heating was a major improvement.
The new hatchery has many new facility upgrades. It’s now an elevated concrete and steel building that exceeds hurricane building codes. We can better filter and treat incoming seawater. Another new hatchery feature is a back-up power generator which is useful if power is unavailable, especially after hurricanes. All these improvements will radically reduce our post-storm recovery response times from months to days.
The purpose of the building is dictated by its source of funding. The hatchery is part of a $17 million Louisiana Natural Resource Damage Assessment (NRDA) project of the BP oil spill. It will be used for replenishing public oyster grounds and providing oyster larvae and seed for private oyster culture.
OC: Ocean acidification is a big concern particularly for Pacific Northwest shellfish. How did it become a concern for you in the Gulf region?
JS: Acidification may not only be caused by carbon dioxide impact on our oceans, but also by riverine or storm water runoff in our estuaries. Over the years, I have seen oyster larvae failures at Grand Isle and attributed it to unfavorable conditions with our ambient water. Researchers working with Whiskey Creek Oyster Hatchery in Oregon have seen similar larvae failures due to their more acidic water. They discovered a simple solution to save their oysters: pumping a saturated solution of soda ash (an antacid) into the hatchery’s seawater lines to raise the pH to 8.25, which is ideal for oysters. Learning from Whiskey Creek’s experience, we are using soda ash to do the same.
OC: What is your future hope for this hatchery, and oysters in Louisiana from an aquaculture and wild ecosystem perspective?
JS: It is important that we have a viable oyster fishery in Louisiana to help support our coastal economy, ecological services, and our culture and cuisine. Wild oyster production is naturally cyclical, but hatcheries can help augment wild production by providing larvae for public and private oyster seed production. Hatcheries can also support private oyster culture by improving survival, shell growth, meat yield, and overall production, which traditionally accounts for nearly 80% of the oysters harvested in Louisiana.