Virginia Institute of Marine Science
2009 Submerged Aquatic Vegetation Distribution and Abundance Survey of Virginia’s Chesapeake Bay and its Tributaries and the Seaside Bays of the Delmarva Peninsula
Project Description as Proposed:
Submerged aquatic vegetation (SAV) is a critical living resource in Chesapeake Bay that has undergone rapid and dramatic baywide fluctuations in distribution and abundance over the last two decades, and is being subjected to declines in water quality and to ever increasing pressure from recreational, commercial, and industrial demands. Because SAV is dependent on good water quality to which it responds over short time scales, it can be an important indicator of water quality.
In 2009, VIMS will continue the annual SAV survey program, begun in 1984, by mapping SAV in the shoal areas of the entire Chesapeake Bay and its tributaries from aerial photography acquired during late spring to late summer. Black & white aerial photography will be acquired at a photographic scale of approximate 1:24,000, following guidelines that address tidal stage, plant growth, sun angle, turbidity, wind, atmospheric transparency, sensor operation and land features to allow for acquisition of photographs under near optimal conditions. Ground data on species distribution and abundance will be collected by participating agencies and citizen groups from as many of the Chesapeake Bay Program segments as possible and included in the final report.
The aerial photographs will be evaluated for SAV signatures using all available information. Photographs containing SAV signatures will be orthographically corrected and mosaiced by USGS 7.5 minute topographic quadrangles using Orthobase and Imagine image processing software. The perimeters of all SAV beds mapped from the 2009 aerial photography will be delineated on-screen using ArcInfo geographic information system (GIS) software and stored in an ArcInfo GIS database. A final report will include maps of all SAV beds and areas of these beds. The report will be published on the VIMS web site as in past years.
Robert J. Orth, 804.684.7392; email@example.com
10/1/2009 - 12/31/2010; Project completed
Final Product Received:
Distribution of Submerged Aquatic Vegetation (SAV) in the Chesapeake Bay and Tributaries and the Delmarva Coastal Bays - 2009 (online at http://vims.edu/bio/sav/sav08/index.html)
Project Summary Provided by Grantee:
The distribution of submerged aquatic vegetation (SAV) in Chesapeake Bay and its tributaries in 2009 was mapped from black and white aerial photographs. These were taken between May and November 2009, at a scale of 1:24,000, encompassing 173 flight lines.
For 2009, 34,768 hectares (85,914 acres) of SAV were mapped in the Chesapeake Bay and its tributaries. SAV increased in all three (Upper, Middle, and Lower) geographic zones delineated for Chesapeake Bay for the second time since 2001. In 2009, SAV increased in 40, decreased in 18, and remained unvegetated in 35 of the 93 CBP segments.
The 3,664 ha increase in baywide SAV coverage occurred primarily in the Middle (2,060 ha) and Lower (1,344 ha) bay zones. These changes reflect a large increase in widgeongrass in four segments in the Middle Bay Zone (Lower Central Chesapeake Bay, Honga River, Pocomoke Sound, and Eastern Bay) and in the Lower Rappahannock River segment in the Lower Bay Zone. The recovery of eelgrass following the 2005 dieback reflects the notable increases in Tangier Sound in the Middle Bay Zone as well as Eastern Lower Chesapeake Bay and Mobjack Bay segments in the Lower Bay Zone. This is the third year of SAV increase in the Lower Bay Zone since the eelgrass dieback. Total area in the Upper Bay Zone remains relatively unchanged from 2008 levels, although there were local offsetting shifts within the zone. The growth and persistence of the SAV bed in the Susquehanna Flats, one of the largest SAV beds in the Bay, continues to be a major success story for SAV recovery today.
In the Middle Bay Zone (44 CBP segments extending south from the Bay Bridge to the Rappahannock River and Pocomoke Sound, and including the Potomac River), SAV increased 15% from 13,970 ha (34,521 ac) in 2008 to 16,030 ha (39,612 ac) in 2009.
In the Lower Bay Zone (28 CBP segments covering the region south from the Rappahannock River and Pocomoke Sound regions to the mouth of the Bay), SAV increased 17% from 7,845 ha (19,386 ac) in 2008 to 9,189 ha (22,706 ac) in 2009.
In the Delmarva Peninsula Coastal Bays Zone (Assawoman, Isle of Wight, Sinepuxent, Chincoteague, and Southern Virginia coastal bays), SAV increased 27% from 5,400 ha (13,344 ac) in 2008 to 6,862 ha (16,958 ac) in 2009.
This report, Distribution of Submerged Aquatic Vegetation (SAV) in the Chesapeake Bay and Tributaries and the Delmarva Coastal Bays - 2009, including maps and data showing SAV distribution is available at: http://vims.edu/bio/sav/sav08/index.html, including an interactive map.
Disclaimer: This project summary provides the federal dollars initially awarded to the grantee. Due to underexpenditure or reprogramming of grant funds, this figure may change. For more information on the allocation of coastal grant funds, please contact Laura McKay, Virginia Coastal Program Manager, at 804.698.4323 or email: Laura.McKay@deq.virginia.gov
A more detailed Scope of Work for this project is available. Please direct your request for a copy to Virginia.Witmer@deq.virginia.gov