Large Scale Bay Grass Restoration
Efforts Continue with Eelgrass Seed Collection
The Department of Natural Resources (DNR) Resource Assessment Service recently
completed a fifth season of eelgrass seed collection in Tangier Sound near
Crisfield, MD using a mechanical harvesting boat introduced in 2004.
There are areas of the Bay where water quality has improved sufficiently to
support bay grasses, yet a lack of seeds prevents recolonization of these areas.
Establishing large beds using seeds collected from healthy beds elsewhere could
lead to vigorous natural revegetation in adjoining areas. In 2003, Maryland
began experimenting with large-scale eelgrass (a high-salinity species of bay
grass) restoration projects in the Patuxent and Potomac Rivers. Collection
efforts since then resulted in over 64 acres being seeded at many locations the
Patuxent and Potomac Rivers.
The 2007 eelgrass seed collection efforts resulted in over 14,000 gallons of
seed material containing an estimated 5 million eelgrass seeds.
Some of the
harvested material was used to make seed bags for immediate distribution
simulating natural seed dispersal. Mesh bags were filled with freshly cut seed
material and deployed with buoys and moorings. This allows seeds to mature and
settle to the bottom in suitable restoration areas. Seed bags were deployed on
the Potomac River near St. George’s Island on June 6th 2007.
The remainder of harvested seed material has been transported to DNR’s Piney
Point Aquaculture Facility where it will be held through the summer in large
tanks to allow for seeds to separate from non-seed material. These seeds will
then be planted this fall on the Potomac River.
Large scale seeding efforts have resulted in the successful establishment of
eelgrass beds at St. Georges Island on the Potomac River. Water quality
conditions at this particular location have allowed for seedlings established
from the2004 and 2005 seed collection to survive the summer conditions (the most
stressful time of year for eelgrass) of 2005 and 2006. DNR will continue to
monitor these new beds in addition to germination and development of this year’s
seeds. DNR will continue to closely monitor both the effect, if any, on the
health of the eelgrass beds from which the seeds are taken as well as the
relative success of the different seeding techniques, the goal being to identify
the most cost-effective large-scale restoration method to employ to meet the
Chesapeake Bay restoration goals.