Phase II: Bay-Wide Assessment
Phase II will expand the Phase I objectives bay-wide and will assess present biotic community structure by identifying and quantifying skeletal sand grains.
Except for coral grains, the most abundant grains of other organisms belong to the groups of living organisms that are dominant.
Grain percentages are thus indicators of the type of environment in which the organisms live.
In contrast, high percentages of coral grains equate to high rates of coral bioerosion and thus to poor coral health (e.g., Lidz and
Hallock, 2000).
Living coral polyps form a thin cover of tissue over a skeleton of calcium carbonate. When the polyps die, increased areas of skeletal
coral are exposed to bioerosion, or breakdown by grazing and boring organisms. With the exception of damselfishes, which are aggressive specialized herbivores that feed on live coral tissue to promote algal growth
within their territories at the base of coral colonies, few grazers and borers in general attack healthy corals.
Phase II will integrate Phase I results and will provide bay-wide database contour maps as decision products to improve knowledge of
biotic community, pollutant source, transport, distribution, and accumulation in bay sediments.
continue to Methods: Introduction
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U. S. Department of the Interior | U.S. Geological Survey
