Eelgrass Restoration Aids Overall Recovery of Coastal Bays
The decline of eelgrass in the Chesapeake Bay, especially in the last 35 years, has generated interest in restoring this valuable habitat. Beginning in 1978, VIMS researchers have investigated techniques for reintroducing eelgrass to areas where it has been eliminated. This page highlights our ongoing and recently completed projects aimed primarily at restoration of eelgrass (Zostera marina) in the Chesapeake Bay and nearby coastal bays.
OUR CURRENT FOCUS
Techniques: Our recent experiments have shown that using eelgrass seeds can be much more efficient and effective than transplanting adult plants for large-scale restoration in our region. However, many young seedlings fail to develop into adult plants, and recent evidence suggests that physical factors (waves and currents) remove many young seedlings before they can become established. Our current experimental work is focused in three areas:
Investigating seed planting as a tool to enhance seedling establishment
Understanding how different physical factors influence seedling establishment at different restoration sites
Investigating the potential importance of high-density, repeated seeding at promising restoration sites in the York and James Rivers
Regions: Recent eelgrass restoration activity has focused on the Virginia coastal bays near Oyster, VA (South Bay, Spider Crab Bay, and Hog Island Bay), as well as the lower York and James Rivers. In the past three years, our seed distributions have performed extremely well in all of these areas. Upcoming work will focus on large distributions in Spider Crab Bay and smaller, exploratory plantings around the lower western shore of Chesapeake Bay. Our work in the Virgnia Coastal Bays is highlighted in a recent special issue of Marine Ecology Progress Series.
Bay scallops: The dramatic success of eelgrass restoration in South Bay has presented the opportunity to re-introduce this once-abundant and commercially valuable member of the seaside marine community. Working with Dr. Marck Luckenbach at VIMS' Eastern Shore Lab, we are initiating a study on juvenile scallop growth and mortality in the restored seagrass bed in South Bay.
RECENT RESEARCH
Seagrass Restoration Techniques: A summary
Here, we provide an overview of those techniques we have used in efforts to restore eelgrass, both manually and mechanized, highlighting the importance of the timing of transplanting, use of fertilizer, labor requirements, and initial success of various transplant techniques.
Researchers: Robert J. Orth, Jill Bieri, James R. Fishman, Matthew C. Harwell, Scott R. Marion, Kenneth A. Moore, Judith F. Nowak, Jacques van Montfrans
Product: 2006. A review of techniques using adult plants and seeds to transplant eelgrass (Zostera marina L.) in Chesapeake Bay and the Virginia Coastal Bays. pp. 1-17. In: S. F. Treat and R. R. Lewis. (eds.). Proc. Conf. Seagrass Restoration: Success, Failure, and the Costs of Both. March 11, 2003. Sarasota, Florida. 175pp.
A Rapid and Simple Method for Transplanting Eelgrass Using Single, Unanchored Shoots
In a large-scale eelgrass (Zostera marina L.) restoration program that began in 1996 in Chesapeake Bay, a simple transplant technique was developed where single, unanchored shoots with rhizomes were planted by hand into the sediment at an angle to a depth of between 25 and 50 mm, allowing the more compact area of the sediment above the rhizome to assist in anchoring the plant.
Researchers: Robert J. Orth, Matthew C. Harwell, James R. Fishman Product: 1999. A rapid and simple method for transplanting eelgrass using single, unanchored shoots. Aquatic Botany 64:77-85.
Mechanized and Manual Transplanting of Eelgrass
The laborious process of manual seagrass transplanting has often limited the size of seagrass restoration efforts. This study tested the efficiency of a mechanized planting boat, previously used for transplanting Halodule wrightii, relative to manual transplanting methods for establishing Zostera marina in Chesapeake Bay.
Researchers: James Fishman, Robert Orth, Scott Marion, and Jill Bieri. Product: 2004. A comparative test of mechanized and manual transplanting of eelgrass, Zostera marina, in Chesapeake Bay. Restoration Ecology 12:214-219.
Mechanical Seed Planter for Transplanting Eelgrass
Few seagrass transplant projects worldwide have relied on seeds, and those projects using Zostera marina (eelgrass) seeds have generally found low rates of seedling establishment (<10%). We compared seedling establishment achieved by a mechanical seed planter with seeds broadcast on the sediment surface by hand.
Researchers: Robert Orth, Scott Marion, Steve Granger, Mike Traber. Product: 2009. Evaluation of a mechanical seed planter for transplanting Zostera marina (eelgrass) seeds. Aquatic Botany 90:204-208.
2008. Restoring eelgrass (Zostera marina) from seed: A comparison of planting methods for large scale projects. SAV Technical Notes Collection (ERDC/TN SAV-87-1). Vicksburg, MS: U.S. Army Engineer Research and Development Center.
Innovative Techniques for Large Scale Seed Based Eelgrass Restoration
Eelgrass restoration efforts using seeds are being increasingly recognized as a viable option for both small and large scale restoration projects. The purpose of this research was to develop methodologies for achieving the full potential for large-scale restoration presented by mechanized eelgrass seed harvesting. The specific goal in this project was to develop techniques and infrastructure to fully exploit potential mechanized seed harvesting capabilities, and to identify optimal conditions for storage and survival of large volumes of harvested seeds.
Researchers: Robert Orth and Scott Marion Product: 2010. Innovative techniques for large scale collection, processing, storage, and dispersal of eelgrass (Zostera marina) seeds. Restoration Ecology 18:514-526.
2007. Innovative techniques for large-scale collection, processing, and storage of eelgrass (Zostera marina) seeds. SAV Technical Notes Collection (ERDC/TN SAV-07-2). Vicksburg, MS: U.S. Army Engineer Research and Development Center.
Please send us an email if you would like a copy of any these products.
