Latest Bay Grass Survey Shows Increases in Maryland’s Coastal Bays

ANNAPOLIS, MD — Submerged Aquatic Vegetation (SAV) in Maryland’s Coastal Bays acreage is increasing, according to a recent survey conducted by the Maryland Department of Natural Resources (DNR) and federal partners.

These bay grasses are technically known as seagrasses in the Coastal Bays, and are important indicators of bay health. Seagrasses have been monitored annually since 1986 through an aerial survey conducted by the Virginia Institute of Marine Sciences and funded by the States of Maryland, Virginia, and the federal government.

Results for the Coastal Bays show that seagrass acreage increased 5 percent in Maryland from 2002 to 2003 to approximately 11,069 acres. The 2003 acreage represents the second highest total documented in the Coastal Bays, and a 315 percent increase since annual data began to be collected in 1986. The 2001 acreage represents the highest yet documented in the Coastal Bays (11,438 in MD).

“This increase in grasses in the Coastal Bays reverses the declines observed in 2002 and are a good sign that it was only a temporary setback to seagrass recovery,” said DNR Secretary C. Ronald Franks. “The growth of these grass nurseries is absolutely essential for the continued improvement of our waters.”

Seagrasses are important to the Coastal Bays because they provide habitat, food, and oxygen for a variety of bay creatures, including crabs, fish, and waterfowl. Seagrasses also help protect shorelines from erosion by reducing wave energy, help to absorb nutrients, and trap sediments that cloud Bay waters.

Increases in seagrass coverage from 2002 were recorded in two of the five major Coastal Bays segments. Grasses in Assawoman Bay increased 18 percent to 496 acres and Isle of Wight Bay increased 31 percent to 342 acres. This represents the largest coverage in Isle of Wight since the annual survey began in 1986 (largest coverage in Assawoman was in 1999 at 648 acres). Although these bays segment saw overall increases in seagrass coverage, localized declines were also observed in these bays.

Seagrass coverage in Sinepuxent Bay decreased approximately 5 percent from 2002 to a total of 2,032 acres. Chincoteague Bay was relatively stable (0.1 percent decrease). Decreases in bay grass coverage and density were observed in several small pockets within Sinepuxent Bay.

Although seagrasses are found in all five major segments of Maryland’s Coastal Bays, they are not distributed evenly. Almost 85 percent of all seagrasses occur along the Assateague Island shoreline.

“It’s not coincidental that we find lower abundances of seagrasses in the northern bays and Newport Bay, ” said Thomas Parham, Chief of DNR’s Tidewater Ecosystem Assessment’s, Living Resource Program. “These are the areas of greatest water quality impacts according to the recently released State of the Maryland Coastal Bays: 2004 report.”

Increased sediment and nutrient inputs from runoff and wastewater treatment act to block sufficient sunlight from reaching seagrasses and are the primary threat to their health. Seagrasses in the Coastal Bays may also be damaged by blooms of harmful algal species (such as Brown Tide) and macroalgae species (aka seaweeds) which further block sunlight from reaching the underwater plants, or physically destroyed by recreational boating and commercial fishing. Natural factors, such as sediment type and wave action also influence the health and location of seagrass beds.

The Maryland Coastal Bays Program is working with local, State, and federal partners to implement the Maryland Coastal Bays Comprehensive Conservation Management Plan, which identifies a variety of actions designed to restore and protect the Coastal Bays, including seagrasses.

"This is encouraging news for the Coastal Bays," said Dave Blazer, Executive Director of the Maryland Coastal Bays Program. "Seagrasses are one of the environmental indicators the program uses to assess the health of the bays. We are currently working on establishing a seagrass acreage goal."

General consensus among the scientific community is that, despite recent increases documented by the aerial survey, seagrass coverage is currently considerably less than in the early 1900s. A disease struck many seagrasses along the east coast in the early 1930s and virtually eliminated bay grasses from the Coastal Bays. The Maryland Coastal Bays Program and DNR are evaluating historic aerial photographs to determine the extent of seagrass coverage during the 1950s.

DNR, in partnership with the Assateague Island National Seashore and others, initiated a comprehensive environmental monitoring program in 2001. Data collected as part of this program will allow identification of specific factors influencing seagrass coverage in different portions of the Coastal Bays.

Unlike the Coastal Bays where grasses are returning naturally, DNR is currently using innovative technologies to restore hundreds of acres of bay grass beds in the Chesapeake Bay. This effort involves the large-scale seeding of grass beds in the portions of the Bay that meet the necessary water quality conditions to support bay grasses, yet are currently lacking adequate seed sources for natural re-vegetation. Because bay grass restoration at this scale has never been attempted before 2004, DNR is working with Virginia Institute of Marine Science (VIMS) and other researchers to improve and refine our seed collection and dispersal techniques applied during the 2004 DNR/VIMS seeding effort of approximately 100 acres.

For more information on Maryland’s Coastal Bays and Bay Grass Restoration efforts, visit the DNR website at: http://www.dnr.state.md.us/coastalbays/index.html

To view the entire 2003 Bay Grass Survey Report and associated maps, visit the Virginia Institute of Marine Science website at: http://www.vims.edu/bio/sav/sav03/

For more information on the Maryland Coastal Bays Program, visit: http://www.mdcoastalbays.org

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