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The pH of a liquid relates its hydrogen ion [proton; H(+)] concentration to a scale from 0-14.  Liquids with pH near 7 are neutral, while liquids whose pH is below 7 are acidic.  Liquids whose pH is above 7 are basic.

Anthropogenic means human-made or human-caused.

Biodiversity is the measure of genetic or species diversity in an area.  Areas with greater biodiversity are usually better able to withstand environmental pressures than other ares.

Chemical compounds are molecules made of multiple atoms bonded together; their unique properties change if they break down or react with other chemicals. 

Climate is the long-term average weather for an area, and it is expected to vary slightly over time.

Climate change describes progressive changes in weather characteristics like temperature, precipitation, or wind.  Changes can be continuous increases or decreases, or they may be changes in variability. Climate change can be natural or man-made.  

Coccolithophores are one-celled plantlike ocean organisms that are covered with round calcium carbonate plates.  They live in the upper ocean in temperate waters.

Eutrophication occurs when high levels of dissolved nutrients accumulate in a body of water, encouraging uncontrolled plant growth.  Bacteria involved in decomposing these large quantities of material use up available oxygen and kill native fish and animal species.

Foraminifera are tiny multicelled ocean organisms with calcium carbonate shells.  They are either predators or they host photosynthetic symbiotic organisms inside their shells. 

Harmful algal blooms occur when toxin-producing algal species grow out of control.  The toxins they release into the water can kill fish and other local organisms.

Photosynthesis is the process that plants carry out to harness the sun's energy into a form that plant cells can use and store.

Preindustrial refers to the period of time before the Industrial Revolution, which began in the mid- to late 1700s.

Pteropods are tiny marine snails that move through the water column with their flapping feet; for that reason, they have sometimes been called "sea butterflies."

Rock weathering slowly breaks down rocks by either physical processes, like freezing, thawing, or geological uplift, or by chemical processes like oxidation, hydration, and hydrolysis.  The process frees ions (charged chemical compounds) into streams, rivers, and the ocean.

Last updated: January 28, 2009

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