Restoration Projects: Underwater Grasses/Submerged Aquatic VegetationMary’s River SAV Restoration
The reduction of nutrient pollution and other environmental measures instituted
in recent years has resulted in some portions of the Bay showing marked increases
in areas covered by underwater grasses—also called submerged underwater vegetation
(SAV). But success has been limited, and those increases that have occurred have
resulted largely from expanding existing beds.
To promote restoration in areas that are suitable for SAV, different replanting
methods are used. As a part of NOAA's effort to restore SAV in the Chesapeake Bay,
the National Marine Fisheries Service's Restoration Center (Office of Habitat
Conservation) awarded $35,000 to the Alliance for the Chesapeake Bay to evaluate
how best to use volunteers in restoring SAV. A volunteer-based restoration program
was used to meet two goals: to assess the effectiveness of transplanting SAV at
sites where water-quality requirements are met but no grasses exist, and to evaluate
the feasibility of increasing public involvement in SAV restoration projects.
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A volunteer diver sorts plant shoot material and bundles them together in
preparation for planting. The water can become quite murky during the initial
planting, so as much above-water preparation is done as possible to simplify and
expedite the planting process.
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Volunteer divers check equipment and coordinate their plan prior to submerging
and planting the tender plant shoots. Small bamboo stakes are used to anchor the
shoots into the sandy bottom.
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Using funding from NOAA’s Restoration Center, the Alliance for the Chesapeake Bay mobilized
its citizen monitoring volunteers to provide an opportunity for the community to become
involved in SAV restoration. The goal was to show that citizen activism could be harnessed
to produce tangible restoration results and to heighten awareness and understanding of water
quality, land-use practices, and individual actions on watershed protection. Volunteers were
used for all aspects of restoration field work, including water-quality monitoring, planting,
and follow-up monitoring. Volunteer divers were recruited and trained in various planting
techniques, while other volunteers began a water-quality monitoring program.
Early indicators showed high survival of the newly planted SAV, but later monitoring how
persistent the SAV was over the winter showed significant declines in long-term survival.
But the project has been a complete success in involving local communities. The project
enabled local citizens to become active participants in the monitoring and restoration of
SAV habitat, and empowered individuals to take stewardship of their watershed. The use of
volunteers, once choice of location, plant source, and water habitat requirement issues
are resolved, will be a very viable tool and workforce to assist in restoring SAV
throughout the Bay.
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A volunteer diver surfaces to obtain another bundle of plant shoots for transplanting. Shallow
depths of two to three feet make it possible to complete plantings using snorkeling gear if
SCUBA is not available, but use of SCUBA allows divers to plant more quickly, placing more
potential transplant shoots into the project area.
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Patuxent River SAV Restoration
Although some portions of the Bay have showed marked increase in SAV coverage, success
has been limited in many areas. Increases that have occurred have resulted largely through
expansion of existing beds. Scientists have suggested that a lack of propagules may hinder
recolonization in many areas that have suitable habitat requirements—but not extensive SAV
beds. Availability and regulatory constraints often limit the ability to transplant from
existing beds. As a result, growing plants in laboratories specifically for transplanting
has been suggested as an alternative method for obtaining transplant material.
A restoration project was designed to test this method, and to continue the use of
volunteer divers in SAV restoration efforts. The novel approach of using
"micropropagation," a laboratory-based method of reproducing numerous propagules from
one parent plant, was the first step to provide the needed plant material. Following
grow-out of the plant shoots in a controlled setting, material was transplanted to sites
selected as having conditions that would support SAV survival.
Although propagules grew very well in sterile lab conditions and developed extensive
roots throughout the cocoa mat planting medium, staking the large mats successfully to
the soft bottom to counteract wave energy proved troublesome, and roots did not grow
down through the mats into soft bottom substrate as well as hoped.
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A volunteer diver prepares one of the 3-foot by 5-foot cocoa mats for transport out to
the planting area and staking to the bottom. Extensive growth of young SAV shoots can be
seen on top mat.
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