Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

World Oceans Month Brings Mixed News for Oysters

13.06.2013
Ocean acidification inhibits shell formation, but interventions at hatcheries may offset some effects, scientists find

In World Oceans Month, there's mixed news for the Pacific Northwest oyster industry.


Research site in Netarts Bay, Oregon, at low tide; rows of bags contain seed oysters.

For the past several years, it has struggled with significant losses due to ocean acidification. Oyster larvae have had mortality rates high enough to render production no longer economically feasible.

Now a new study documents why oysters appear so sensitive to increasing acidity, but also offers some hope for the future.

It isn't necessarily a case of acidic water dissolving the oysters' shells, scientists say. It's water high in carbon dioxide altering shell formation rates, energy usage and, ultimately, the growth and survival of young oysters.

"The failure of oyster seed production in Northwest Pacific coastal waters is one of the most graphic examples of ocean acidification effects on important commercial shellfish," said Dave Garrison, program director in the National Science Foundation's (NSF) Division of Ocean Sciences.

NSF funded the study through its Ocean Acidification Program, part of NSF's Science, Engineering and Education for Sustainability programs.

"This research is among the first to identify the links among organism physiology, ocean carbonate chemistry and oyster seed mortality," said Garrison.

Results of the study are online in the journal Geophysical Research Letters, published by the American Geophysical Union.

"From the time eggs are fertilized, Pacific oyster larvae precipitate roughly 90 percent of their body weight as a calcium carbonate shell within 48 hours," said George Waldbusser, an Oregon State University marine ecologist and lead author of the paper.

"Young oysters rely solely on the energy they derive from the egg because they have not yet developed feeding organs."

During exposure to increasing carbon dioxide in acidified water, however, it becomes more energetically expensive for organisms like oysters to build shells.

Adult oysters and other bivalves may grow more slowly when exposed to rising carbon dioxide levels. But larvae in the first two days of life do not have the luxury of delayed growth.

"They must build their first shell quickly on a limited amount of energy--and along with the shell comes the organ to capture external food," said Waldbusser.

"It becomes a death race of sorts. Can the oyster build its shell quickly enough to allow its feeding mechanism to develop before it runs out of energy from the egg?"

The results are important, marine scientists say, because they document for the first time the links among shell formation rate, available energy, and sensitivity to acidification.

The researchers say that the faster the rate of shell formation, the more energy is needed. Oyster embryos building their first shells need "to make a lot of shell on short order," said Waldbusser.

"As the carbon dioxide in seawater increases, but before waters become corrosive, calcium carbonate precipitation requires more energy to maintain higher rates of shell formation during this early stage."

The researchers worked with Whiskey Creek Shellfish Hatchery in Netarts Bay, Ore. They found that on the second day of life, 100 percent of the larval tissue growth was from egg-derived carbon.

"The oyster larvae were still relying on egg-derived energy until they were 11 days old," said Elizabeth Brunner of Oregon State University and a co-author of the paper.

The earliest shell material in the larvae contained the greatest amount of carbon from the surrounding waters.

Increasing amounts of carbon from respiration were incorporated into shells after the first 48 hours, indicating an ability to isolate and control the shell surfaces where calcium carbonate is being deposited.

Waldbusser notes that adult bivalves are well-adapted to growing shell in conditions that are more acidified, and have evolved several mechanisms to do so.

These include use of organic molecules to organize and facilitate the formation of calcium carbonate, pumps that remove acid from the calcifying fluids, and outer shell coatings that protect minerals to some degree from surrounding waters.

Waldbusser said that the results help explain previous findings at the Whiskey Creek Hatchery of larval sensitivity to waters that are high in carbon dioxide but not corrosive to calcium carbonate.

They also explain carryover effects later in larval life of exposure to high carbon dioxide, similar to human neonatal nutrition effects.

The discovery may be good news, scientists say, because there are interventions that can be done at hatcheries that may offset some of the effects of ocean acidification.

Some hatcheries have begun "buffering" water for larvae--essentially adding antacids to incoming waters--including the Whiskey Creek Hatchery and the Taylor Shellfish Farms in Washington.

The study provides a scientific foundation for the target level of buffering.

"You can make sure that eggs have more energy before they enter the larval stage," said Waldbusser, "so a well-balanced adult diet may help larval oysters cope better with the stress of acidified water."

Media Contacts
Cheryl Dybas, NSF (703) 292-7734 cdybas@nsf.gov
Mark Floyd, Oregon State University (541) 737-0788 mark.floyd@oregonstate.edu
Peter Weiss, American Geophysical Union (202) 777-7507 pweiss@agu.org
The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2012, its budget was $7.0 billion. NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and other institutions. Each year, NSF receives about 50,000 competitive requests for funding, and makes about 11,500 new funding awards. NSF also awards about $593 million in professional and service contracts yearly.

Cheryl Dybas | EurekAlert!
Further information:
http://www.nsf.gov

More articles from Ecology, The Environment and Conservation:

nachricht Gran Chaco: Biodiversity at High Risk
17.01.2018 | Humboldt-Universität zu Berlin

nachricht Dead trees are alive with fungi
10.01.2018 | Helmholtz Centre for Environmental Research (UFZ)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Morbid Obesity: Gastric Bypass and Sleeve Gastrectomy Are Comparable

17.01.2018 | Health and Medicine

Researchers identify new way to unmask melanoma cells to the immune system

17.01.2018 | Health and Medicine

Genetic discovery may help better identify children at risk for type 1 diabetes

17.01.2018 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>