Full document / COSOC-W-86-002 - the National Sea Grant Library

types of geomorphological features and biotic communities
which are found there.
Clark (1962) used the term 'typology' to refer to the
structural and biotic characteristics of a given biogeographic
subregion. These characteristics may vary within, as well as
between, areas of the same biogeographical regional type in
response to climatic or micro-environmental influences. In this
study, the elements of the comprehensive estuarine classification
scheme for the Chesapeake Bay which apply to coastal geomorphology
and vegetative structure and composition, correspond to typology.
The coastal zone of Virginia is structurally and biotically
complex. In addition to the main stem of the Bay, several types
of basins are found throughout the coastal zone, including tidal
rivers and creeks, bays, sounds, embayments, lagoons, and ponds.
Shoreline physiography is characterized by such features as
indented coasts, unindented coasts, peninsulas, spits, inlets,
beaches, dunes, cliffs, barrier islands, bay islands, submerged
bars, intertidal reefs and aquatic beds. The patterns, abundance
and diversity of biota associated with these coastal features is
influenced by hydroiogic factors such as tidal range, duration of
inundation, flushing, flooding, wave energy, circulation patterns
and salinity, and by dynamic processes such as shoreline erosion
and accretion, sedimentation, inlet migration, and island
morphogenesis. The coastal zone and waters of the Chesapeake Bay
provides habitat for a variety of animal species which are
residents or concentrate in abundance during part of the year in
the form of feeding, breeding and spawning, nursery, wintering,
resting and sheltering areas.
F.cologir; valuation — The site contributes substantially to
maintaining or enhancing the ecological quality of the
estuarine environment, as a whole, and the local environment,
in particular, as evidenced by the vital functions it
performs and the societal benefits it provides.
Under thi3 criterion, sites are evaluated according to their
importance to: food chain support; waterfowl and wildlife
utilization; water quality control and maintenance; erosion and
flood control; recreational, scenic and historical pursuits;
fishing, hunting and other consumptive uses; and other support
functions.
Naturalnpgq — The site approximates a natural ecological
unit where ecosystem processes operate relatively undisturbed
by human activities.
This criterion is used to evaluate two essential factors in
reserve selection: (1) assurance that the site encompasses an
adequate portion of key land and water areas to approximate an
ecological unit; and (2) assurance that the site is in a natural
state.
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