martes, 28 de junio de 2016

What Oysters Reveal about Sea Change

Head out with ​M​ark Bittman as he braves the elements and cruises along the waters off of Marshall, CA. There, UC Davis researchers are helping local food producers like Hog Island Oyster Farm monitor the effects of ocean acidification on the marine ecosystem.

Self-study activity:
Watch the video and say whether the statements below are true or false.

1 Mark Bittman  lives in San Franscisco.
2 Oysters were discovered 2,000 years ago.
3 Ocean water is being deprived of carbon dioxide.
4 The high acidity in the water is happening all year round.
5 Terry cultivates oysters all year round.
6 Tessa Hill is conducting nationwide research into the acidification of ocean waters.

Mark Bittman: I've been to the San Francisco Ferry Building many times since its reopening as a food destination. But now that I'm living out here, Saturday morning visits have become routine. The views never get old, and the markets and the raw bars are big draws.
For the most part, you can't get fresher seafoods than an oyster. Shucked raw on ice, grilled or fried, oysters have been cultivated for at least 2,000 years and consumed since prehistoric times. But there are troubled waters ahead for oysters, in large part because of ocean acidification. This is basically a change in the chemistry of ocean water brought about by absorption of carbon dioxide from the atmosphere. And it's affecting the marine ecosystem, including the shellfish so many of us love.
Tessa Hill of UC Davis is helping monitor the impact of ocean acidification on marine invertebrates all along the Pacific Coast, including oysters harvested at the Hog Island Oyster Farm. So I met Tessa at the farm along with Terry Sawyer, who's one of the co-owners of Hog Island Oyster Company.
Let's see. I'm going to guess that water is sequestering carbon.
Tessa Hill: Right, so 30% of what we put into the atmosphere ends up in the ocean. When you add that carbon dioxide into the sea water, it changes the acidity of the water. And animals have a harder time finding their building block to make a shell.
Mark Bittman: You're changing their environment, and you're robbing them of the level of pH that they want.
Terry Sawyer: A lot of these stresses that we're talking about are also bringing about disease or bacterial effects. So you got hatcheries over there, very high densities. These animals get stressed, your hatchery would just be completely wiped up.
Tessa Hill: What you end up with are animals that are weakened. They take longer to get to reproductive age.
Mark Bittman: For now, the research shows that high acidity in the water is seasonal and related to upwellings. So hatcheries, like Terry's, are responding by not spawning new oysters when conditions are bad. But by 2030, upwellings are expected to last longer, and they may even be year-round in many places by 2050. Tessa's collaboration with Terry has become a model experiment.
Tessa Hill: What we started by doing is just deploying an extra set of sensors out on his sea water intake lines. The idea was, "Look, we're learning some interesting things from this data. Terry can plan around some business decisions. We're learning about the Tomales Bay Watershed, and the oceanography in this bay." And people started to take notice. Our regional system got money from the National Ocean Observing System to pick this as a site to monitor for climate change and ocean acidification.
Mark Bittman: What's next on the national project?
Tessa Hill: The West Coast program will extend from California all the way up to Alaska. The northeast coast and the Gulf Coast, in particular, are very susceptible to these impacts of ocean acidification, and so I would expect that monitoring systems like these will start to crop up in those locations as well.
Terry Sawyer: So then it's policy. It all has to be taken to the state and national levels to put money towards alternative forms of energy, transportation, whatever.
Tessa Hill: Absolutely.
Mark Bittman: As we headed back to shore, I could see tourists at the farm. Shucking oysters by the bucket and settling in to eat out al fresco. We joined in. As we gobbled out a few dozen just shucked oysters, I thought about the impact of this research. One thing it will do is help keep such delights on the table, but this type of collaboration will also lead to policies that will promote a healthier marine system and planet. That's something we can all hope for.
University of California Global Food Initiative Berkeley Food Institute
Wondering what I'm doing out in California? Find out. Click the subscribe button, and watch more episodes.

1T 2F 3F 4F 5F 6F