Summer field work is in full swing at the Shinnecock Indian Reservation with CHRP (Coastal Habitat Restoration Project). CCE and the Shinnecock Nation have been busy planting both beach grass (Ammophila breviligulata) and marsh grass (Spartina alterniflora) all spring and summer, but over a couple weeks in July, we switched gears to focus on collecting eelgrass seed while they were ripe and ready to release in Shinnecock Bay. Eelgrass (Zostera marina) is our local seagrass species, which is a true flowering plant that grows completely submerged in estuarine waters, forming critical marine habitat for our finfish and shellfish.
In this region, eelgrass reproductive shoots finish seed development during the summer months of June through August, and the rate of seed development depends largely on water temperatures and therefore proximity to cool ocean water. This means that eelgrass flowering shoots that are growing in creeks and enclosed embayments are ripe earlier than eelgrass growing closer to inlets or other more exposed water bodies that maintain cooler temperatures. We collect eelgrass flowers when the maximum number of seeds on the flower shoot are ripe and about to release. This requires consistent monitoring for several weeks leading up to collection day, as seed maturity varies from year to year along with the the local climate.
Eelgrass seed collected this year in Shinnecock Bay was used for seed restoration along the Shinnecock Reservation shoreline. We utilized a method of seed restoration known as Buoy Deployed Seeding (BuDs) devised here at CCE by Chris Pickerell, which has since been used around the world by restoration scientists. This method was developed in order to allow people to restore eelgrass by seed without having to bring the collected reproductive shoots back to a facility with a flowing saltwater tank; with this method, flower shoots can be collected and deployed at the restoration site on the same day. It also allows for citizens to help in the net filling process, which helps the restoration team increase their productivity and increases citizen stewardship.
The collected flowering shoots are stuffed into aquaculture pearl nets which are sewn shut, attached to a buoy/block system, and allowed to swing with the tides and waves, dropping seeds naturally over the course of 2-3 weeks until the flower shoots are spent. Several buoy systems can be arranged into a grid to cover a desired restoration area and nets can be filled with a set amount of flowers to allow for a known initial seed planting density. 100 of these buoy/block/net systems were deployed in mid-July along the Shinnecock Nation’s shoreline, with each set up containing an average of approximately 350 viable seeds. We are in the process of retrieving the remaining buoy systems this week. The area will be monitored in early spring to scout for new seedlings emerging, and results will determine the success of this effort and future eelgrass restoration efforts at this site.