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Estuaries are eternally enriched. Their positions at the foot of
watersheds and their convenience as receiving bodies for the wastes
of cites, towns and farms results in continuous addition of
nutrients - those elements and compounds which are essential for
organic production. Such materials must be added to these complex
bodies of water to sustain production, since there is a net loss of
water and its contents to the oceans. Enrichment from land and the
ocean and the subsequent cycling of the original chemicals or their
derivatives contribute to the extraordinarily high values of
estuaries for human purposes. Many estuaries are able to assimilate
large quantities of nutrients despite the great fluctuations which
occur with variations in the flow from tributaries. The nutrients
can be stored, incorporated in standing crops of plants, released,
cycled and exported - and the system frequently achieves high
production of plants and and animals without creation of any
undesirable results of enrichment. Excessive enrichment with the
same elements and compounds can, however, be highly detrimental to
estuaries and their uses. Coastal cities are usually located on the
estuaries which provided a harbor for the- and which now receive
partially treated sewage and other wastes from the expanding
population and industrial activity. Conversion of woodlands to
agricultural use and the extensive application of fertilizers have
resulted in the flow of large quantities of nutrients down the hill
or slopes and eventually into the estuary.
Estuaries exist along the edge of the oceans and seas, and are char
acterized by the dilution of sea water by inflowing fresher waters.
The motion and interaction of these two types of water (fresh and
salt water) determine the salinity distribution within the estuary
and that, in turn, affects the organisms residing there. The
purpose of this vol ume is to review the status of our
understanding of estuarine circu lation and how the circulation
patterns affect living and nonliving resources in estuaries. For
many years, the primary paradigm for estuarine circulation was the
two-layered net or nontidal gravitational circulation pattern first
proposed by Dr. Donald Pritchard in his studies of the James River
estuary. During the last decade or so, research has focused on the
many variations about this theme and the factors that control the
transport processes. Many of these aspects are covered in the
initial papers in this volume. Water movement, of course, is of
interest be cause it transports marine organisms, sediments, and
pollutants. Es tuarine circulation has a significant effect on
estuarine food chains, and on the distribution and abundance of
organisms, such as the American oyster, that are freely transported
by the currents during larval stages. The intent is to bring
together many of these topics in a single volume. This volume is
dedicated to Dr. Donald W."
Estuaries exist along the edge of the oceans and seas, and are char
acterized by the dilution of sea water by inflowing fresher waters.
The motion and interaction of these two types of water (fresh and
salt water) determine the salinity distribution within the estuary
and that, in turn, affects the organisms residing there. The
purpose of this vol ume is to review the status of our
understanding of estuarine circu lation and how the circulation
patterns affect living and nonliving resources in estuaries. For
many years, the primary paradigm for estuarine circulation was the
two-layered net or nontidal gravitational circulation pattern first
proposed by Dr. Donald Pritchard in his studies of the James River
estuary. During the last decade or so, research has focused on the
many variations about this theme and the factors that control the
transport processes. Many of these aspects are covered in the
initial papers in this volume. Water movement, of course, is of
interest be cause it transports marine organisms, sediments, and
pollutants. Es tuarine circulation has a significant effect on
estuarine food chains, and on the distribution and abundance of
organisms, such as the American oyster, that are freely transported
by the currents during larval stages. The intent is to bring
together many of these topics in a single volume. This volume is
dedicated to Dr. Donald W."
Estuaries are eternally enriched. Their positions at the foot of
watersheds and their convenience as receiving bodies for the wastes
of cites, towns and farms results in continuous addition of
nutrients - those elements and compounds which are essential for
organic production. Such materials must be added to these complex
bodies of water to sustain production, since there is a net loss of
water and its contents to the oceans. Enrichment from land and the
ocean and the subsequent cycling of the original chemicals or their
derivatives contribute to the extraordinarily high values of
estuaries for human purposes. Many estuaries are able to assimilate
large quantities of nutrients despite the great fluctuations which
occur with variations in the flow from tributaries. The nutrients
can be stored, incorporated in standing crops of plants, released,
cycled and exported - and the system frequently achieves high
production of plants and and animals without creation of any
undesirable results of enrichment. Excessive enrichment with the
same elements and compounds can, however, be highly detrimental to
estuaries and their uses. Coastal cities are usually located on the
estuaries which provided a harbor for the- and which now receive
partially treated sewage and other wastes from the expanding
population and industrial activity. Conversion of woodlands to
agricultural use and the extensive application of fertilizers have
resulted in the flow of large quantities of nutrients down the hill
or slopes and eventually into the estuary.
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