Sentences with phrase «for aragonite»

Model simulations indicate that polar surface waters will become undersaturated for aragonite in the near future for the Arctic (atmospheric carbon dioxide of 400 - 450 ppm) and by mid-century for the southern ocean off the Antarctic (atmospheric carbon dioxide of 550 - 600 ppm).

This is especially true for aragonite, the mineral used by corals and many other marine organisms to grow their skeletons.

We present such a relationship for aragonite saturation state for waters off Northern California based on in situ bottle sampling and instrumental measurements of temperature, salinity, and dissolved oxygen.

Not exact matches

Higher concentrations of chlorophyll in the areas of pronounced reef growth suggests that an abundance of food may provide the excess energy needed for calcification in waters with low aragonite saturation.

Low levels of aragonite, an essential mineral in the formation of scleractinian skeletal structures, in the region make it difficult for the coral polyps to develop their rugged coral skeletons.

The saturation state of seawater for a mineral such as aragonite is a measure of the potential for the mineral to form or to dissolve.

«A decline in the saturation state of carbonate minerals, especially aragonite, is a good indicator of a rise in ocean acidification,» said Li - Qing Jiang, an oceanographer with NOAA's Cooperative Institute for Climate and Satellites at the University of Maryland and lead author.

For example, on Heron Island Reef in the GBR, variations in pH and aragonite saturation state over one day were greater than the predicted changes in ocean chemistry globally by 2050.

As the science develops, it is important for managers to design select examples of coral reef areas in a variety of ocean chemistry and oceanographic regimes (e.g., high and low pH and aragonite saturation state; areas with high and low variability of these parameters) for inclusion in MPAs.

One approach is to develop empirical regional models that enable aragonite saturation state to be estimated from existing hydrographic measurements, for which greater spatial coverage and longer time series exist in addition to higher spatial and temporal resolution.

For example, few data are available for the polar winter, and it is not known whether aragonite - undersaturated areas decrease in size with the seasonal freezing of sea iFor example, few data are available for the polar winter, and it is not known whether aragonite - undersaturated areas decrease in size with the seasonal freezing of sea ifor the polar winter, and it is not known whether aragonite - undersaturated areas decrease in size with the seasonal freezing of sea ice.

A reef tank, however, is frequently better suited for marine sand, which is usually made from aragonite.

Finally, a question for David and Gavin: McNeil & Matear (2008, PNAS 2Dec08, «Southern Ocean acidification: A tipping at 450 - ppm atmospheric CO2») suggest that by 2030 and no later than 2038 seasonal aragonite undersaturation is likely to disrupt the Southern Ocean ecosystem, due to key forms of zooplankton being unable to form shells.

The results of this study and of Feely et al. (2008) for the coastal North Pacific and Orr et al. (2008) for the Arctic show that undersaturation of surface waters with respect to aragonite is likely to become reality in a few years only.

For corals to be able to build reefs, which requires rapid growth and strong skeletons, the surrounding water needs to be highly supersaturated with aragonite.

The more negative the change in aragonite saturation, the larger the decrease in aragonite available in the water, and the harder it is for marine creatures to produce their skeletons and shells.

Present - day ocean surface waters are supersaturated for the major carbonate mineral forms used by marine organisms, including the more soluble form aragonite (corals, many mollusks) and the less soluble form calcite (coccolithophores, foraminifera, and some mollusks).

Holds that for most open - ocean surface waters, aragonite undersaturation occurs when carbonate ion concentrations drop below approximately 66 µmol kg - 1

Decreasing the amount of carbonate ions in the water makes conditions more difficult for both calcite users (phytoplankton, foraminifera and coccolithophore algae), and aragonite users (corals, shellfish, pteropods and heteropods).

At some times of year, acidification has already reached a critical threshold for organisms living on Alaska's continental shelves.145 Certain algae and animals that form shells (such as clams, oysters, and crab) use carbonate minerals (aragonite and calcite) that dissolve below that threshold.

Would we for instance change the Mg / Ca ratio triggering shifts to a calcite rather than the modern aragonite state of the oceans?

Scenarios of OA by anthropogenic CO2, driven by CGMs, predict a decline of pH by 0.3 units and a shoaling of the horizon for dissolution of carbonate minerals, particularly aragonite, by the end of the century as a result of increased anthropogenic CO2 in the ocean (Caldeira and Wickett 2003, 2005; Orr et al. 2005; Raven et al. 2005; Meehl et al. 2007).

By 2050, only about 15 percent of reefs will be in areas where aragonite levels are adequate for coral growth.

McLaughlin's research shows that there is now evidence for falling concentrations of aragonite — the result of surface waters becoming more acidic because of the sea ice melting — making it more difficult for the shellfish to maintain their shells.

Sclerosponges are sponges that build a massive skeleton of aragonite and can live for many centuries.