Some of the earliest ecological studies were developed to
determine how energy flowed through an ecosystem and
whether these systems were net importers or exporters of
organic matter. In estuaries, measurements of TEM are
challenging as their dynamic nature makes them difficult
to characterize. Estuarine ecologists most often focus on
components of TEM, like the net ecosystem metabolism
or gross primary production, which can indicate how
much organic matter is consumed within an estuary or
exported to the coastal ocean, as well as how impacted
an estuary is by anthropogenic inputs of nutrients and
organic matter.
Bibliography
Golley, F. B., 1993. A History of the Ecosystem Concept in Ecology:
More than the Sum of the Parts. New Haven: Yale University
Press.
Kemp, W. M., Smith, E. M., Marvin-DiPasquale, M., and Boynton,
W. R., 1997. Organic carbon balance and net ecosystem metabolism of Chesapeake Bay. Marine Ecology Progress Series,
150, 229–248.
Nixon, S. W., and Pilson, M. E. Q., 1984. Estuarine total system
metabolism and organic exchange calculated from nutrient
ratios: an example from Narragansett Bay. In Kennedy, V. S.
(ed.), The Estuary as a Filter. New York: Academic Press,
pp. 261–290.
Odum, H. T., and Hoskin, C. M., 1958. Comparative studies on the
metabolism of marine waters. Publications of the Institute of
Marine Science, 5, 16–46.
Odum, H. T., and Odum, E. P., 1955. Trophic structure and productivity of a windward coral reef community on Eniwetok Atoll.
Ecological Monographs, 25, 291–320.
Smith, S. V., and Hollibaugh, J. T., 1997. Annual cycle and
interannual variability of ecosystem metabolism in a temperate
climate embayment. Ecological Monographs, 67, 509–533.
Cross-references
Dissolved Oxygen
Nutrients
ESTUARY CONSERVATION
Colin Levings
Fisheries and Oceans Canada, Science Branch, Pacific,
Centre for Aquaculture and Environmental Research,
West Vancouver, British Columbia, Canada
Definition
Conservation is the act of protection or maintenance over
time of an ecosystem and its components. Estuary conservation can be directed to consumptive use of a living estuarine resource or nonconsumptive use such as preserving
an estuary as a reserve or protected area.
Overview
Historically, conservation of estuaries and their resources
were maintained by a lack of overexploitation, an absence
of industrial activity that resulted in large-scale habitat disruption, and an ability of indigenous people to adapt to
change. A good example is the harvest of eulachon
(Thaleichthys pacificus), a smelt-related fish that migrates
through some northeast Pacific Ocean estuaries to spawn
in spring. Groups of up to 10,000 native people from
nearby areas gathered at the specific estuaries to harvest
the fish. The oil from the eulachon was also exported for
trade inland several hundred kilometers through the
mountains via “grease trails” to interior tribes (Mitchell
and Donald, 2001). This estuarine resource and its habitat
maintained a culture and socioeconomic system for centuries and thus were conserved (Turner and Clifton, 2009).
The conservation of estuaries and estuarine resources
has become more difficult in the postindustrial era.
Although ecologists have developed knowledge of how
estuaries function in support of conservation, the information has not always been applied systematically through
policies. The inexorable movement of people from the
interior of continents to coasts and estuaries has increased
harvesting pressure, and the globalization of trade with its
requirement for major port development to deliver goods
has created challenges. Global warming and related climate change is also a factor. Up until about 30 years ago,
conservation methods were often focused on efforts to
control population dynamics of single species or preserve
habitats without consideration of the ecosystem.
Conservation biology, an advancing stage in the application of science to conservation problems, addresses the
biology of species, communities, and ecosystems that are
perturbed, either directly or indirectly, by human activities
or other agents (Soule, 1985). A strong conservation plan
to address problems will require careful development of
a vision, goals, and objectives for the estuary. Conservation biology requires a more holistic view of the estuary
and especially understanding of complex processes such
as energy flow, genetic changes, maintenance of freshwater flow, and sediment transport. A comprehensive conservation or management plan for an estuary and its resources
thus requires major data gathering and syntheses which
can be facilitated by the use of models. As well the linkages between socioeconomics and the estuarine ecosystem are now appreciated. This is sometimes called the
“comprehensive landscape approach”. Tools such as the
Integrated Valuation of Ecosystem Services model
(InVEST) (Nelson et al., 2009) are available and are
recommended to help the complex task of estuary
conservation.
Bibliography
Mitchell, D., and Donald, L., 2001. Sharing resources on the North
Pacific Coast of North America: the case of the eulachon fishery.
Anthropologia, 43, 19–35.
ESTUARY CONSERVATION
303
determine how energy flowed through an ecosystem and
whether these systems were net importers or exporters of
organic matter. In estuaries, measurements of TEM are
challenging as their dynamic nature makes them difficult
to characterize. Estuarine ecologists most often focus on
components of TEM, like the net ecosystem metabolism
or gross primary production, which can indicate how
much organic matter is consumed within an estuary or
exported to the coastal ocean, as well as how impacted
an estuary is by anthropogenic inputs of nutrients and
organic matter.
Bibliography
Golley, F. B., 1993. A History of the Ecosystem Concept in Ecology:
More than the Sum of the Parts. New Haven: Yale University
Press.
Kemp, W. M., Smith, E. M., Marvin-DiPasquale, M., and Boynton,
W. R., 1997. Organic carbon balance and net ecosystem metabolism of Chesapeake Bay. Marine Ecology Progress Series,
150, 229–248.
Nixon, S. W., and Pilson, M. E. Q., 1984. Estuarine total system
metabolism and organic exchange calculated from nutrient
ratios: an example from Narragansett Bay. In Kennedy, V. S.
(ed.), The Estuary as a Filter. New York: Academic Press,
pp. 261–290.
Odum, H. T., and Hoskin, C. M., 1958. Comparative studies on the
metabolism of marine waters. Publications of the Institute of
Marine Science, 5, 16–46.
Odum, H. T., and Odum, E. P., 1955. Trophic structure and productivity of a windward coral reef community on Eniwetok Atoll.
Ecological Monographs, 25, 291–320.
Smith, S. V., and Hollibaugh, J. T., 1997. Annual cycle and
interannual variability of ecosystem metabolism in a temperate
climate embayment. Ecological Monographs, 67, 509–533.
Cross-references
Dissolved Oxygen
Nutrients
ESTUARY CONSERVATION
Colin Levings
Fisheries and Oceans Canada, Science Branch, Pacific,
Centre for Aquaculture and Environmental Research,
West Vancouver, British Columbia, Canada
Definition
Conservation is the act of protection or maintenance over
time of an ecosystem and its components. Estuary conservation can be directed to consumptive use of a living estuarine resource or nonconsumptive use such as preserving
an estuary as a reserve or protected area.
Overview
Historically, conservation of estuaries and their resources
were maintained by a lack of overexploitation, an absence
of industrial activity that resulted in large-scale habitat disruption, and an ability of indigenous people to adapt to
change. A good example is the harvest of eulachon
(Thaleichthys pacificus), a smelt-related fish that migrates
through some northeast Pacific Ocean estuaries to spawn
in spring. Groups of up to 10,000 native people from
nearby areas gathered at the specific estuaries to harvest
the fish. The oil from the eulachon was also exported for
trade inland several hundred kilometers through the
mountains via “grease trails” to interior tribes (Mitchell
and Donald, 2001). This estuarine resource and its habitat
maintained a culture and socioeconomic system for centuries and thus were conserved (Turner and Clifton, 2009).
The conservation of estuaries and estuarine resources
has become more difficult in the postindustrial era.
Although ecologists have developed knowledge of how
estuaries function in support of conservation, the information has not always been applied systematically through
policies. The inexorable movement of people from the
interior of continents to coasts and estuaries has increased
harvesting pressure, and the globalization of trade with its
requirement for major port development to deliver goods
has created challenges. Global warming and related climate change is also a factor. Up until about 30 years ago,
conservation methods were often focused on efforts to
control population dynamics of single species or preserve
habitats without consideration of the ecosystem.
Conservation biology, an advancing stage in the application of science to conservation problems, addresses the
biology of species, communities, and ecosystems that are
perturbed, either directly or indirectly, by human activities
or other agents (Soule, 1985). A strong conservation plan
to address problems will require careful development of
a vision, goals, and objectives for the estuary. Conservation biology requires a more holistic view of the estuary
and especially understanding of complex processes such
as energy flow, genetic changes, maintenance of freshwater flow, and sediment transport. A comprehensive conservation or management plan for an estuary and its resources
thus requires major data gathering and syntheses which
can be facilitated by the use of models. As well the linkages between socioeconomics and the estuarine ecosystem are now appreciated. This is sometimes called the
“comprehensive landscape approach”. Tools such as the
Integrated Valuation of Ecosystem Services model
(InVEST) (Nelson et al., 2009) are available and are
recommended to help the complex task of estuary
conservation.
Bibliography
Mitchell, D., and Donald, L., 2001. Sharing resources on the North
Pacific Coast of North America: the case of the eulachon fishery.
Anthropologia, 43, 19–35.
ESTUARY CONSERVATION
303