Navigation Links
Shellfish face an uncertain future in a high CO2 world
Date:5/26/2009

Overfishing and disease have decimated shellfish populations in many of the world's temperate estuarine and coastal ecosystems. Smithsonian scientists, led by Whitman Miller, ecologist at the Smithsonian Environmental Research Center in Edgewater, Md., have discovered another serious threat to these valuable filter feedersrising levels of atmospheric carbon dioxide that contribute to the acidification of open ocean, coastal and estuarine waters. Their findings are being published in the open-access, peer-reviewed journal PLoS ONE, May 27.

For shellfish and other organisms that have calcium carbonate shells and structures, the problem begins when atmospheric CO2 dissolves in seawater and creates carbonic acid that is then rapidly transformed into carbonate and bicarbonate ions in the water. Increased acidity tips the balance toward bicarbonate formation and away from carbonate. Less carbonate in the water means that shellfish have fewer building blocks to generate their shells. If the water is acidic enough, shells can even begin to dissolve.

"Estuarine and coastal ecosystems may be especially vulnerable to changes in water chemistry caused by elevated CO2 because their relative shallowness, reduced salinity and lower alkalinity makes them inherently less buffered to changes in pH than in the open ocean," said Miller. For many calcifying organisms, CO2-induced acidification poses a serious challenge because these organisms may experience reduced rates of growth and calcification that "when combined with other environmental stresses, could spell disaster."

Larval oysters are thought to be particularly susceptible to acidification since larvae produce shells made of aragonite, a crystalline form of calcium carbonate that is prone to erosion at low pH. Adult oysters continue to build shell but generate calcite, a more durable form of calcium carbonate. In Miller's study, the larvae of Eastern oysters (Crassostrea virginica) and Suminoe oysters (Crassostrea ariakensis) were cultured in estuarine water that was held at four separate CO2 concentrations, reflecting atmospheric conditions from the pre-industrial era, the present, and those predicted in the coming 50 and 100 years. To test the effects of acidification, Miller monitored their growth and measured the amounts of calcium carbonate deposited in larval shells over the course of one month.

Miller and his team found that Eastern oysters experienced a 16 percent decrease in shell area and a 42 percent reduction in calcium content when specimens in the pre-industrial CO2 treatment were compared with those exposed to the levels predicted for the year 2100. Surprisingly, the closely related Suminoe oysters from Asia showed no change to either growth or calcification.

The results reported suggest that the impacts of acidification may be tied to a species' unique evolutionary history and environmental setting, implying that predictions may be more complex than previously thought. "In the Chesapeake Bay, oysters are barely holding on, where disease and overfishing have nearly wiped them out. Whether acidification will push Eastern oysters, and the many species that depend on them, beyond a critical tipping point remains to be seen" said Miller.

With numbers so critically lowthe oyster population in the Chesapeake Bay today stands at just 2 percent of what it was in colonial timesfuture losses could have dire consequences, both environmentally and economically. Indeed, the recently enacted Federal Ocean Acidification Research and Monitoring Act of 2009 recognizes the urgent need to begin addressing impacts of acidification on estuaries and their biota.

With the continued burning of fossil fuels, further acidification is unavoidable. Miller's team is keenly interested in what the biological and ecological responses will be in order to better inform current and future environmental restoration efforts. "In a high CO2 world, calcifying organisms may well begin to lose out to competition with non-calcifiers, a situation that could fundamentally change benthic communities. Understanding how such changes may play out in estuaries and coastal waters, which teem with calcifying biota, and which are also the centers of many commercial fisheries and human activities, seems especially urgent" said Miller.


'/>"/>

Contact: Rebecca Walton
rwalton@plos.org
44-122-346-3333
Public Library of Science
Source:Eurekalert

Related biology news :

1. Shellfish and inkjet printers may hold key to faster healing from surgeries
2. Pacific shellfish ready to invade Atlantic
3. Saltwater sleuths: Seeking clues to help determine the ages of fish and shellfish populations
4. Underwater microscope helps prevent shellfish poisoning along Gulf Coast of Texas
5. Dealing with taxonomic uncertainty for threatened and endangered species
6. Managing uncertainty important in ecological balance: ASU researcher
7. Uncertainty drives the evolution of cooperative breeding in birds
8. Preventing ear infections in the future: Delivering vaccine through the skin
9. Grasslands: The future of sustainable agriculture
10. Better water use could reduce future food crises
11. A glimpse of future GMES Sentinel-1 radar images
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/2/2016)... 2016   SoftServe , a global digital ... an electrocardiogram (ECG) biosensor analysis system for continuous ... asset. The smart system ensures device-to-device communication between ... and mobile devices to easily ,recognize, and monitor ... vehicle technology advances, so too must the security ...
(Date:11/29/2016)... BioDirection, a privately held medical device company developing novel ... concussion and other traumatic brain injury (TBI), announced today ... the U.S. Food and Drug Administration (FDA) to review ... meeting company representatives reviewed plans for clinical development of ... a planned pilot trial. "We are ...
(Date:11/28/2016)... , Nov. 28, 2016 ... a rate of 16.79%" The biometric system market ... grow further in the near future. The biometric system ... billion in 2022, at a CAGR of 16.79% between ... system, integration of biometric technology in smartphones, rising use ...
Breaking Biology News(10 mins):
(Date:12/8/2016)... Spain , Dec. 8, 2016  Anaconda BioMed ... the development of the next generation neuro-thrombectomy system for ... appointment of Tudor G. Jovin, MD to join its ... serve as a strategic network of scientific and clinical ... the development of the ANCD BRAIN ® to ...
(Date:12/8/2016)... ... December 08, 2016 , ... Microbial genomics ... Awards. uBiome is one of just six company finalists in the Health & ... to uBiome, companies nominated as finalists in this year’s awards include Google, SpaceX, ...
(Date:12/8/2016)... , Dec. 8, 2016 Soligenix, Inc. ... company focused on developing and commercializing products to treat ... announced today that it will be hosting an Investor ... ET on the origins of innate defense regulators (IDRs) ... review of oral mucositis and the recently announced and ...
(Date:12/8/2016)... Eutilex Co. Ltd. today announced that it ... A financing. This financing round included participation from DS ... Bio Angel. This new funding brings the total capital ... since its founding in 2015. The ... commercialization of its immuno-oncology programs, expand its R&D capabilities ...
Breaking Biology Technology: