■ Providing areas for agriculture and timber (e.g., rice, various berries, and
certain species of trees).
■ Recharging groundwater, thereby reducing the need for water treatment
facilities and replacing groundwater used for human and/or agricultural
purposes.
■ Serving as nurseries for fish and shellfish.
■ As sediment-laden water flows through a wetland from the surrounding
watershed, the sediments are deposited or trapped, reducing siltation into
lakes, rivers, and streams. Ecological services of reducing siltation
include: preserving important and/or sensitive aquatic habitats by
reducing turbidity, thereby increasing fishery resources, reducing changes
in fish migration patterns, reducing the impact on and loss of submerged
vegetation, reducing sedimentation buildup behind dams and in
reservoirs, and reducing coastline alteration.Wetland Degradation
Countries with the most wetlands are Canada (14% of land area), the Russian
Federation, and Brazil. Wetlands were once about 10% of the land area of the
United States but are currently about 5% now, with Florida and Louisiana having
the most wetlands. Ninety percent of the loss of wetlands is due to the
conversion of land for agriculture and ten percent is due to urbanization. As
important as wetlands are, they are fragile ecosystems that are being continually
threatened by human activity (i.e., one-third of all endangered species live in
wetlands). Listed below are examples of how the world’s wetlands have been
compromised.
Anthropogenic Causes of Wetland Degradation and Their Environmental
Consequences
Anthropogenic Causes Environmental Consequence(s)Agriculture Wetlands have been drained to utilize the rich
organic soil. Water is drained from wetlands by
cutting ditches into the ground, which collect
and transport water out of the wetland. This
lowers the water table and dries out the wetland.
Consequences include salinization and soil
compaction.Commercial fishing The depletion of native species of fish and