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Potomac Project
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Map of the Potomac Seed Collection

This page provides a more in depth illustration of the seed collection process used by the MD-DNR as part of the large scale restoration process in the Potomac River.

Seeds harvested from healthy donor beds supply our restoration efforts. Successful collection and transportation of millions of seeds in 2003, 2004, and 2005 demonstrated that this scale of seed collection is practical for use in the Chesapeake Bay.

Eelgrass Seed Harvest and Collection
2003: Reproductive shoots from healthy eelgrass beds containing mature seeds were collected manually from Tangier Sound. Harvesting took place on May 20, 23, and 27-30 and yielded 2.3 million seeds, 250,000 of which were viable for broadcast.

2004: A mechanical harvest boat was utilized to increase the efficiency and amount of reproductive material collected. From May 24 to June 4, 2004, seeds were collected from donor beds in the Little Annemessex River. In nine cutting days the mechanical harvester collected approximately 71.92 L of eelgrass reproductive material. In 2004, the portion of reproductive material transported to Piney Point for seed extraction yielded 15.12 million seeds. After the seed processing and storage process was complete, 7% of the collected seeds (or 1,058,400 seeds) were viable for broadcast.

2005: Reproductive material was harvested from the Little Annemessex River and the mouth of Acre Creek (Big Annemessex River) from May 23 to June 8, 2005. The harvest machine collected approximately 109.5 L of eelgrass seeds from 21.6 acres of eelgrass beds yielding 12 million seeds. After the seed processing and storage process was complete, 20% of the collected seeds (or 2,527,000 seeds) were viable for broadcast.

a photo of the mechanical harvester
Eelgrass reproductive shoots harvested
mechanically by specially designed boat between mid-May to mid-June.

a photo of the mechanical harvester transferring material to the DNR collection boat
Harvested material is transferred to DNR collection boat

a photo of eelgrass being brought aboard the DNR collection boat another photo of eelgrass being brought aboard the DNR collection boat a photo of eelgrass in a holding tub
Eelgrass being brought aboard DNR boat where it is collected in a holding tub

a photo of a blue crab in harvested eelgrass material.
Blue crab in harvested eelgrass material.
Bay grasses are an important habitat!
a photo of mature eelgrass seeds still in reproductive shoots
Mature eelgrass seeds still in reproductive shoots
a photo of eelgrass reproductive shoot.
Eelgrass reproductive shoot.

Harvested eelgrass material bagged for either:
1. Immediate distribution to restoration sites for dispersal via the seed bag method. Go to planting page to read more about seed bag dispersal method.
2. Boat transport to Piney Point Aquaculture Facility for seed processing (see below)

a photo of the seed bag method. another photo of the seed bag method. a photo of the bags of seed

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Eelgrass Seed Processing at Piney Point Aquaculture Facility
Maryland DNR has established equipment at its Piney Point Aquaculture Facility to process collected eelgrass seeds. (Learn More about the Piney Point Aquaculture Facility).  Reproductive shoots are processed and held in large tanks at the Piney Point facility until the seeds drop from the reproductive shoots (July to early August). Seeds are separated from shoot material and stored in large tubs until they are broadcast into the field in October.

a photo of the large holding tanks.
Large holding tanks

a photo showing the seeds being separated from reproductive material.
Seeds being separated from reproductive material


a photo of a handful of eelgrass seeds.

a photo showing seeds being collected from final holding tanks.

Eelgrass seeds that have been separated
from reproductive shoot material
Seeds being collected from final holding
tank for broadcast in the field

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Next: Read about eelgrass seed planting


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The folks that have made this all possible