Archive for October, 2008

Long-term effects of predicted future seawater CO2 conditions on the survival and growth of the marine shrimp Palaemon pacificus

The increasing atmospheric concentration of carbon dioxide (CO2) has been driving all marine organisms to live in increasingly acidic environments. In the present study, we evaluated the long-term effects of increased seawater CO2 on survival, growth, feeding and moulting of the marine shrimp Palaemon pacificus. The shrimps were reared in seawater equilibrated with air containing 1,000 ppmv (parts per million by volume, seawater pH 7.89 ± 0.05) or 1,900 ppmv (pH 7.64 ± 0.09) CO2, the atmospheric CO2 concentrations predicted for the year 2100 and 2300, for 30 and 15 weeks, respectively. Survival was significantly suppressed in both experimental groups compared to respective controls; final survival rates were 55% (experimental) vs. 90% (control) in the 1,000 ppmv experiment, and 65% (experimental) vs. 95% (control) in the 1,900 ppmv experiment. Growth was unaffected in the 1,000 ppmv experiment but significantly depressed compared to the control after 7 weeks in the 1,900 ppmv experiment. Feeding was unaffected by either treatment. Moulting frequency was significantly affected in both 1,000 ppmv (experimental > control) and 1,900 ppmv (experimental < control) experiments. Egg production was suppressed in the 1,000 ppmv shrimps compared with the control (no observation was made in the 1,900 ppmv experiment). In addition, the second antennae determined at the end of the experiment were significantly shorter in the 1,000 ppmv shrimps than in the control. The present results demonstrate for the first time that the predicted future seawater CO2 conditions would potentially reduce shrimp, and possibly other crustacean, populations through negatively affecting mortality, growth, and reproduction. This could threaten entire marine ecosystem through disrupting marine food web.
Continue reading ‘Long-term effects of predicted future seawater CO2 conditions on the survival and growth of the marine shrimp Palaemon pacificus’

Coccolithophore response to climate and surface hydrography in Santa Barbara Basin, California, AD 1917–2004

The varved sedimentary AD 1917–2004 record from the depositional center of the Santa Barbara Basin (SBB, California) was analyzed with monthly to annual resolution to yield relative abundances of six coccolithophore species representing at least 96% of the coccolithophore assemblage. Seasonal/annual relative abundances respond to climatic and surface hydrographic conditions in the SBB, whereby (i) the three species G. oceanica, H. carteri and F. profunda are characteristic of the strength of the northward flowing warm California Counter Current, (ii) the two species G. ericsonii and G. muellerae are associated with the cold equatorward flowing California Current, (iii) and E. huxleyi appears to be endemic to the SBB. Spectral analyses on relative abundances of these species show that all are influenced by the El Niño Southern Oscillation (ENSO) and/or by the Pacific Decadal Oscillation (PDO). Increased relative abundances of G. oceanica and H. carteri are associated with warm ENSO events, G. muellerae responds to warm PDO events, and the abundance of G. ericsonii increases during cold PDO events. Morphometric parameters measured on E. huxleyi, G. muellerae and G. oceanica indicate increasing coccolithophore calcification from ~1917 until 2004 concomitant with rising pCO2 and sea surface temperature in the region of the SBB.
Continue reading ‘Coccolithophore response to climate and surface hydrography in Santa Barbara Basin, California, AD 1917–2004’

Marie Curie Position for an Early-Stage Researcher in Kiel

(CALMARO  RT6 – IFM-GEOMAR/ UiB)

Environmental and physiological controls of calcification in fish and cephalopods

 

The Leibniz Institute of Marine Sciences (IFM-GEOMAR) at the University of Kiel is one of the leading institutes in marine research in Germany. The major goal of the institute is research and development in all parts of marine sciences. Apart from basic research, applied projects between science and economy are also supported. IFM-GEOMAR is a foundation by public law, jointly funded by the federal und provincial government. The institute is a member of the Leibniz Association (WGL) and the German Marine Research Consortium (KDM).

IFM-GEOMAR is coordinator and member of the Marie Curie Initial Training Network CalMarO (Calcification by Marine Organisms). CALMARO aims at improving the career perspectives of early researchers by offering structured training in the field of Calcification by Marine Organisms as well as providing complementary skills and exposing the researchers to other sectors including private companies. CALMARO comprises investigation of calcareous structures as well as calcification processes and the sensitivities to changes in environmental conditions at all scales ranging from cellular, organism, population to ecosystem, and regional to global levels.

We are looking for an Early-Stage Researcher (ESR) to study the environmental and physiological controls of calcification in fish and cephalopods.
Continue reading ‘Marie Curie Position for an Early-Stage Researcher in Kiel’

Scientist impresses

The world for South Penrith resident Laura Parker is her oyster just as long as she continues her research on ocean acid levels.

The 25-year-old University of Western Sydney student, who is researching the way rising acid in our oceans is affecting commercial oysters, won best student presentation award at two ocean-climate conferences this year.

Presenting pioneering research from her PhD, “The impact of ocean acidification and temperature on the early development of oysters”, Ms Parker rocked the climate change conferences in Spain in May and in Monaco in October.
Continue reading ‘Scientist impresses’

Acidic oceans crank up the volume

MOSS LANDING — The same thing attributed to creating global warming is having an unexpected side effect: a noisier ocean.

As carbon dioxide is pumped into the atmosphere, which many scientists blame for global warming, it is also being absorbed into the oceans, which are becoming more acidic and therefore noisier, according to researchers at the Monterey Bay Aquarium Research Institute.

A louder ocean could be problematic for marine animals like whales and dolphins that rely on sonar to navigate and find food.

Keith Hester, a researcher with the aquarium’s ocean chemistry team, and his colleagues predict sounds will travel 70 percent farther in 2050 as a result of increased carbon dioxide in the ocean.

“Eighty-five percent of all the carbon dioxide emitted into the atmosphere will go into the ocean,” said Peter Brewer, a co-author on the paper and expert on ocean acidification.
Continue reading ‘Acidic oceans crank up the volume’

Lesson comes live from reef

Lab allows extended underwater study

Eight-year-old Nicole Popp and other third-graders at Lanikai Elementary Charter School recently had an unusual guest speaker — her father, Brian, underwater in the Florida Keys.

The University of Hawaii geology-geophysics professor was on his third 10-day mission in the habitat Aquarius anchored 60 feet below the ocean surface in a coral reef. UH oceanography student Christina Bradley also was on the mission topside in a support role.
Continue reading ‘Lesson comes live from reef’

Novel microcosm system for investigating the effects of elevated carbon dioxide and temperature on intertidal organisms

In addition to the predicted rise in temperature, a recognised consequence of increased atmospheric CO2 is ocean acidification. The response of marine organisms to the stresses associated with acidification is still not understood, and a number of recent experiments have addressed this problem. The starting point for many of these studies has been the development of a system by which seawater pH can be altered and then maintained. The current paper presents details of a temperature- and pH-controlled microcosm system, which enables the establishment of a tidal regime, for the experimental investigation of intertidal organisms. Two climate scenarios were simulated to evaluate the system’s precision and accuracy; Year 2008 (‘low’ [CO2]: 380 ppm and 14°C) conditions and Year 2100 (‘high’ [CO2]) conditions (based on the IPCC—Intergovernmental Panel on Climate Change—2007 A2 scenario, ‘high’ [CO2]: 1250 ppm and 2.0 to 5.4°C warming). The temperature and seawater carbonate chemistry were reliably maintained for 30 d during which time newly settled barnacle cyprids were allowed to metamorphose into juveniles, then grow and develop. The pH and [CO2] had 95% confidence intervals of ±0.03 units and ±17 ppm, respectively, under low [CO2] conditions, and of ±0.02 units and ±43 ppm, respectively, under high [CO2] conditions. The tidal regime is fully adjustable, and on this occasion was set to a 6 h cycle. These microcosms have proved ideal for studying benthic organisms from a variety of near-surface environments and at different stages of their life-cycle. Continue reading ‘Novel microcosm system for investigating the effects of elevated carbon dioxide and temperature on intertidal organisms’

Novel microcosm system for investigating the effects of elevated carbon dioxide and temperature on intertidal organisms

In addition to the predicted rise in temperature, a recognised consequence of increased atmospheric CO2 is ocean acidification. The response of marine organisms to the stresses associated with acidification is still not understood, and a number of recent experiments have addressed this problem. The starting point for many of these studies has been the development of a system by which seawater pH can be altered and then maintained. The current paper presents details of a temperature- and pH-controlled microcosm system, which enables the establishment of a tidal regime, for the experimental investigation of intertidal organisms. Two climate scenarios were simulated to evaluate the system’s precision and accuracy; Year 2008 (‘low’ [CO2]: 380 ppm and 14°C) conditions and Year 2100 (‘high’ [CO2]) conditions (based on the IPCC—Intergovernmental Panel on Climate Change—2007 A2 scenario, ‘high’ [CO2]: 1250 ppm and 2.0 to 5.4°C warming). The temperature and seawater carbonate chemistry were reliably maintained for 30 d during which time newly settled barnacle cyprids were allowed to metamorphose into juveniles, then grow and develop. The pH and [CO2] had 95% confidence intervals of ±0.03 units and ±17 ppm, respectively, under low [CO2] conditions, and of ±0.02 units and ±43 ppm, respectively, under high [CO2] conditions. The tidal regime is fully adjustable, and on this occasion was set to a 6 h cycle. These microcosms have proved ideal for studying benthic organisms from a variety of near-surface environments and at different stages of their life-cycle.
Continue reading ‘Novel microcosm system for investigating the effects of elevated carbon dioxide and temperature on intertidal organisms’

The “Ocean Carbon Biogeochemistry” program has established an “Ocean Acidification Subcommittee”

“Ocean acidification is a high priority research topic identified by OCB. The far-reaching effects of ocean acidification on marine biogeochemical cycles and biology, combined with the increasing interest in the topic both nationally and internationally, prompted the OCB-SSC to recommend the formation of an Ocean Acidification Subcommittee. With approval from the OCB-SSC, the Ocean Acidification subcommittee members were invited from the U.S. community of researchers to cover the spectrum of topics relevant to ocean acidification.
Continue reading ‘The “Ocean Carbon Biogeochemistry” program has established an “Ocean Acidification Subcommittee”’

Climate Change Seeps into the Sea

Good news has turned out to be bad. The ocean has helped slow global warming by absorbing much of the excess heat and heat-trapping carbon dioxide that has been going into the atmosphere since the start of the Industrial Revolution.

All that extra carbon dioxide, however, has been a bitter pill for the ocean to swallow. It’s changing the chemistry of seawater, making it more acidic and otherwise inhospitable, threatening many important marine organisms.

Scientists call ocean acidification “the other carbon dioxide problem.” They warn that because it causes such fundamental changes in the ocean, it could impact millions of people who depend on the ocean for food and resources. “The growing amount of carbon dioxide in the ocean could have a bigger effect on life on Earth than carbon dioxide in the atmosphere,” says JPL’s Charles Miller, deputy principal investigator for NASA’s new Orbiting Carbon Observatory, scheduled to launch next January.
Continue reading ‘Climate Change Seeps into the Sea’


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