wetlands

Readings on marshes and submerged aquatic vegetation

Wetlands, including both tidal marshes and submerged aquatic grass beds (also known as SAV, for submerged aquatic vegetation), are critical elements of the Chesapeake Bay system, both as habitats and food sources and because of their effects on nutrient and energy cycling, erosion and sedimentation, and other aspects of the larger ecosystem. An estuary that loses its wetlands relies on algae as the only major group of primary producers and loses an important stabilizing or regulating function.

This group of readings begins with a pair of chapters from the Lippson and Lippson field guide, Life in the Chesapeake Bay. These are provided to give you a quick introduction to the major groups of plants and animals that can be found in seagrass beds and to the major plants in fresh, brackish, and saline tidal marshes. These are followed by selections from The Coastal Wetlands of Maryland, by McCormick and Somes. The first half of this selection is included primarily because it has many pictures of different types of wetland vegetation and provides a more comprehensive description of tidal marsh habitat and marsh grass life cycles. The second discusses wetland ecology in some detail, including a brief review of the different kinds of animals that may be found in wetlands and their roles in the food web.

The following selection, by Hershner and Wetzel, provides some additional information on wetland ecology and also focuses on historical trends in the abundance of submerged aquatic vegetation. This is followed by the chapter by Sanders, which briefly reviews the effects of nutrients and toxic materials on submerged aquatic vegetation, on marsh grasses, and on phytoplankton. (The effects are probably better understood for SAV at this point than for the other two main groups of primary producers.) A summary of research on habitat requirements for submerged aquatic vegetation and the relationship between SAV distribution and water quality is provided in the article by Dennison and others (the article is only slightly longer than the list of authors!)

Because seagrasses are critical food sources for waterfowl in the Chesapeake Bay area, the chapter by Perry is included to highlight the ecological repercussions of the decline in SAV abundance.

Additional links with information about marshes and SAV are provided in section 2 of this page.

1. Library reserve packet:

Lippson, R. and Lippson, A.J., 1984, Life in the Chesapeake Bay, Johns Hopkins University Press, ch. 6 ("Seagrass meadows and weed beds") and ch.7 ("Marshes")
McCormick, J. and Somes, H.A., Jr., 1982, The Coastal Wetlands of Maryland, Md. Dept. of Natural Resources Coastal Zone Management Program, excerpts from ch. 1, "The coastal wetlands of Maryland" and ch. 2, "Values of the coastal wetlands"
Dennison, W.C., Orth, R.J., Moore, K.A., Stevenson, J.C., Carter, V., Kollar, S., Bergstrom, P.W., and Batiuk, R.A., 1993, Assessing water quality with submersed aquatic vegetation, Bioscience, v.43, p.86-94.
Hershner, C. and Wetzel, R.L., 1987, Submerged and emergent aquatic vegetation of the Chesapeake Bay, in Majumdar, S.K., Hall, L.W., Jr., and Austin, H.M., eds., Contaminant Problems and Management of Living Chesapeake Bay Resources, Pennsylvania Academy of Science, ch. 6
Sanders, J.G., 1987, Contaminant effects on primary producers in Chesapeake Bay, in Majumdar and others, ch. 17.
Perry, M.C., 1987, Waterfowl of Chesapeake Bay, in Majumdar and others, ch. 5

2. Pages from the World Wide Web:

Tidal Marsh

Submerged Aquatic Vegetation (SAV)

Submerged Aquatic Vegetation in Chesapeake Bay (Virginia Institute of Marine Science)
Habitat requirements for underwater Bay grasses
DNR Baygrass Restoration
Underwater Bay Grasses and their Restoration (EPA)
1999 SAV field observations
Chesapeake Bay SAV special reports