Corals surface area

Adsorbed, occluded, and included impurities are said to be coprecipitated. That is, the impurity is precipitated along with the desired product, even though the solubility of the impurity has not been exceeded. Coprecipitation tends to be worst in colloidal precipitates (which have a large surface area), such as BaS04, Al(OH)3, and Fe(OH)3. Figure 7-3 shows that phosphate coprecipitated with calcium carbonate in coral is proportional to the concentration of phosphate in seawater. By measuring P/Ca in ancient coral, we can infer the concentration of phosphate in the sea at the time the coral lived. 

The storage of C02 in the deep ocean is an area of active modeling and some experiments. At issue is the retention time for various sites as well as the biological impacts. Advocates of deep injection point out that even in the absence of deliberate injection, the oceans already receive a portion of the carbon released from fossil fuels because of the continuous exchange of C02 between the atmosphere and the oceans. Add C02 to the atmosphere and some of it will move naturally to the ocean, as equilibrium is sought at the ocean surface.18 Also under study are the biological impacts of additional C02 in the near-surface ocean—for example, the impacts on coral reefs. 

Dyed coral may show streaks, patches, or accumulations of dye around any holes or cracks. The dye is oiJy on the surface, so an area that has been chipped or cracked after the material was dyed may show a lack of colour (Fig. 11.13). 

Particles containing plutonium and small amounts of americium resulting from atmospheric safety trials remain in the area of the trial sites—the motus of Colette, Ariel and Vesta on Mururoa Atoll. The Study analysed these types of particles, found in samples of sand and coral collected from the surface of the motu of Colette and in sand taken from a sandbank adjacent to it. 

Coral reefs occupy a large part of the seas in the tropics of the Pacific and the Caribbean. They are the most diverse and complex marine communities, supporting thousands of fish, algae, and invertebrate species. Studies and actual spills have shown that moderate concentrations of dissolved or dispersed hydrocarbons can kill both the coral and its occupants. Damage depends on the depth, with coral that is near the surface (down to about 6 m) being particularly vulnerable to oil. Many of the animals can repopulate the area rapidly, but since the coral is their primary support, full recovery depends largely on the recovery or recolonization of the coral. Once dead, the coral itself can be very slow to recover. Oil also has several sublethal effects on coral, such as slowed growth or respiration and unnatural coloration. 

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