Conserving Freshwater and Coastal Resources in a Changing Climate

Photography by Bill Silliker Jr.
Wetland Restoration: The restoration of ecosystems
can increase an area’s natural resilience to rapid
climate change. For example, many wetlands that
have been historically drained for agriculture can be
reestablished. Wetland hydrology can be restored by
terminating any deliberate drainage and re-establishing
water flow into the wetland basin. Soil saturation
will encourage the growth of wetland plants. However,
wetland restoration efforts have less chance for success
in areas where water supply is low due to reductions in
surface runoff, precipitation, or groundwater recharge
(Hartig et al., 1997).
Dam Removal: Removing existing dams on rivers
can be an effective way to enhance aquatic species’
ability to migrate and maintain natural hydrologic regimes
as climates change. Dams impede the mobility of
species such as migratory fish that move from marine
to riverine areas to spawn, and will obstruct their ability
to find a more habitable climate. Dam removals can
face environmental and societal obstacles. Disposal or
release of contaminated sediment that may exist behind
dams over time can be a significant issue. Dam removal
is also counter to increasing interest in the use of dams
for hydroelectric power generation as a carbon-free, renewable
source of energy. However, dam removal may
be more feasible for obsolete and relic dams and for
dams that produce little or no hydroelectric power.
Sustainable Dam Management: For dams that continue
to meet current needs for water supply, hydropower,
flood control and recreation, sustainable dam
management can improve conditions and therefore resiliency
compared to existing conditions. Practices such
as flow management and fish passage can allow for more
optimal flow and mobility.
Stream Flow Protection: Hydrologic regimes are
affected by many activities beyond dams, including
impervious surfaces, water withdrawals, and modifications
to channels and riparian areas. Developing local
and state policies that protects water resources at levels
needed for maintenance of ecosystem function and
services is an important tool to protect the hydrologic
regime of freshwater and estuarine systems. This type
of policy may become more important as precipitation
patterns change and droughts become more frequent as
a way to balance needs of various human uses and the
needs of freshwater and coastal ecosystems.
Fishery Harvest Management: Many fish populations,
particularly in coastal areas, are already overexploited
from commercial and recreational fishing
(Combes, 2005). Limiting the catch would maintain a
higher population of species, increasing the resilience
to harmful climate change impacts.
Water Conservation: Freshwater ecosystems may
already be threatened by excessive residential, commercial
and industrial water uses. Heightened competition
between users and changing climate conditions
are likely to put further pressure on these ecosystems.
Water conservation policies can help manage human
demand for these resources. Identification of important
or endangered ecosystems can help inform decisions to
withdraw water from other, less threatened sources (US
EPA, n.d.).
Artificial Aeration: Summer fish kill in lakes due to
low dissolved oxygen, as a result of altered timing and
temperature of seasons can be addressed with artificial
aeration. These methods act to increase oxygen levels in
the water. “Bubblers” function with a deep-water intake
that produces rising bubbles of air. Mechanical surface
aerators, known as “splashers,” float on the surface of
the water and spray droplets of water in a radial pattern.
Ecological consequences that should be considered with
the use of these devices involve the disturbance of bottom
sediments, ice cover, and vertical density stratification
(McCord, Schladow, Miller 2000).
Conserving Freshwater and Coastal Resources in a Changing Climate
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