Fooling Mother Nature When Real World Conditions Make the Going Tough

Piece Description

Narration: With Green Acre Radio this is Martha Baskin. At Dabob Bay, a saltwater inlet in the North part of Hood Canal, a chemistry experiment is going on. Seawater has become so corrosive that Taylor Shellfish is seeing if they can grow baby shellfish, and the algae they feed on, in tanks. Taylor has been growing shellfish here for almost a century. “WHAT YOU’RE SEEING IN HERE IS WHAT WE CALL CONTINUOUS FLOW ALGAE CULTURE. SO IN THESE SYSTEMS YOU’VE GOT STERILIZED, PASTEURIZED NUTRIFIED SEAWATER THAT’S DRIPPING INTO THESE BAGS AT THE SAME RATE WE’RE HARVESTING ALGAE OUT OF THE BAG.” Pasteurized seawater? Well it beats the real thing, explains the company’s Bill Dewey. Every day oceans absorb a third of the world’s carbon dioxide. Research on the West Coast shows steep declines in sea urchins, crabs and massive shellfish mortality.

Five years ago natural sets of shellfish failed to grow in Willapa Bay, one of Washington State’s main growing areas. Then the same thing happened at Dabob Bay and Oregon’s Whiskey Creek Hatchery. Oysters are the most vulnerable. “THEY USE DIFFERENT FORMS OF CALCIUM CARBONATE AS THEY GROW. FOR THE FIRST FEW DAYS OF THEIR LIFE THEY’RE USING THIS AMORPHOUS CALCIUM CARBONATE THAT DISSOLVES REALLY EASILY. IF WE CAN GET THEM THROUGH THESE VULNERABLE PHASES IN THE HATCHERY INTO THE JUVENILE STAGES WE CAN STILL SURVIVE AS AN INDUSTRY. AT LEAST FOR A PERIOD OF TIME UNTIL THE OCEAN GETS SO CORROSIVE THAT EVERYTHING IS DISSOLVING OUT THERE.”

New monitoring equipment allows them to measure constantly fluctuating CO2 levels in seawater. When levels are low they bring sea water in for their harvesting experiments. When levels are high they stop the flow. Taylor purchased the new equipment with funding assistance from Senator Maria Cantwell. Bill Dewey looks at a computer graph. “YOU CAN SEE THE PCO2 LEVEL RIGHT NOW ON OUR 30 FOOT INTAKE AND IT’S RUNNING A THOUSAND TWENTY-TWO SO ABOVE SIX OR SEVEN HUNDRED IT’S GETTING CORROSIVE TO THE SHELLS OF BABY LARVAE.” ‘P’ stands for partial pressure.  

Researchers at the National Oceanic Atmospheric Administration are trying to help the industry adapt. Experiments at the Northwest Fisheries Science Center are looking at how increased levels of CO2 are impacting the entire marine ecosystem. In a lab the size of a boxcar, bubbling tanks simulate ocean waters past, present and future. Biologist Paul McElhany. “WHAT WE’RE TRYING TO DO IS SIMULATE THE HISTORICAL OCEAN, THE CURRENT OCEAN AND THE POTENTIAL FUTURE OCEAN IN TERMS OF THE AMOUNT OF CARBON DIOXIDE THAT’S IN THE WATER.” A pre-industrial tank reads 280 parts per million of carbon in the atmosphere. A current tank 380 parts per million, the global average. Other tanks read higher, 780 and 2000.  “THERE’S SOME UNCERTAINTY ABOUT WHAT CARBON IS GOING TO BE IN THE FUTURE DEPENDING ON JUST HOW MUCH FOSSIL FUEL PEOPLE BURN.  IN PUGET SOUND WE SEE SOME REALLY HIGH VARIATION SO IT MIGHT DROP BELOW 100 PARTS PER MILLION OR GO OVER A THOUSAND WHICH IS REALLY QUITE HIGH.”  Researchers can bubble in Co2, or air or pure oxygen. The larvae of Pacific oysters and Pinto abalone are then exposed to the water in each tank. Both species concern the Northwest seafood industry. “WE LOOK AT SURVIVAL AND GROWTH AND CALCIFICATION, THEIR ABILITY TO PRODUCE SHELLS.”

Survival of other marine life is also at risk. Again biologist Paul McElhany. “A LOT OF THE ZOOPLANKTON THAT ARE THE BASIS OF THE FOOD WEB THAT ARE EATEN BY FISH AND OTHER THINGS THAT WE LIKE TO EAT. A LOT OF THE BENTHIC ORGANISMS THAT LIVE ON THE BOTTOM OF THE SEAFLOOR LIKE SEA STARS AND SEA URCHINS AS WELL AS THE BIVALVES THE OYSTERS, THE MUSSELS ALL OF THOSE THINGS ARE CALCIFYING.” We step outside to another make-shift lab. It’s full of oxygen tanks, nitrogen and circulation pumps. This is where CO2 found in today’s seawater is being removed. “WHILE IT’S QUITE EASY TO ADD CO2 TO THE SEAWATER BY JUST BUBBLING IT, REMOVING CO2 IS QUITE CHALLENGING AND THAT’S A PART OF THE PROBLEM. ONCE WE GET IT INTO THE ATMOSPHERE WE GET IT INTO THE OCEANS THERE’S REALLY NO WAY TO GET IT OUT AGAIN.”

Any positive findings?  Increased levels of Co2 may help the growth of species like phytoplankton and algae, says McElhany. Shellfish feed on algae so higher levels of Co2 mean more food for them. But what good is more food if their shells can’t grow? The success of Taylor Shellfish’s hatchery operation depends on careful monitoring of the seawater’s carbon content. The challenge is they can only do it for so long. Freshwater intake is critical. “SO IT’S NOT AN IDEAL SOLUTION AND IT’S A SOLUTION THAT’S ONLY AVAILABLE TO SOME PLACE LIKE A HATCHERY. ALL OF THE WILD OYSTERS THAT ARE OUT THERE SPAWNING THEY REALLY DON’T HAVE A CHOICE. THEY HAVE TO TAKE THE WATER THEY’RE DEALT WITH.” McElhany’s team is gearing up to start a new series of experiments when spawning starts again in January. Research at Taylor Shellfish is ongoing.