The Legacy of Agricultural Reclamation on Channel and Pool Networks of Bay of Fundy Salt Marshes
- 200 Downloads
We assess the status of channel networks and pools of two tidal salt marshes recovering from more than a century of agricultural reclamation on the Bay of Fundy, Canada. A process of largely unmanaged restoration occurred at these sites since abandonment of agricultural activities during the first half of the twentieth century. Each recovering marsh was compared to a reference marsh that was never drained or ditched. We field mapped channel networks at all marshes and used aerial photographs to map the pre-abandonment channel network at one of the sites. The recovering marshes have hybrid channel networks that feature highly variable channel morphologies, loss of original channels, and incorporation of drainage ditches. Although channel networks in recovering marshes integrate agricultural ditches, the recovering marsh networks may not be substantially increased in length or density. Our aerial photograph analysis shows that channel density at one of the recovering marshes is comparable to the pre-abandonment density, but with reduced sinuosity. Field mapping of permanent tidal pools on the lower Bay marshes revealed that pools cover 13% of the recovering marsh, compared to ∼5% of the reference marsh. This study demonstrates that these essential marsh features can be regained through restoration or simple abandonment of drainage infrastructure.
KeywordsRecovering wetlands Salt marsh Tidal channels Creeks Ponds Restoration
The Natural Science and Engineering Research Council of Canada (NSERC), the Bay of Fundy Ecosystem Partnership and the Royal Canadian Geographic Society of Canada provided financial support for this project. We are grateful to A. Sabourin and S. Byers, who assisted with field mapping; S. Byers also provided many helpful suggestions regarding the design of the project. We thank R. Sengupta and G. Baker for their technical advice concerning GIS methodologies. We appreciate the comments from two anonymous reviewers that improved this manuscript.
- Byers, S.E. and G.L. Chmura. 2007. Salt marsh vegetation recovery on the Bay of Fundy. Estuaries and Coasts 30: 869–877.Google Scholar
- Fell, P.F., R.S. Warren, and W.A. Niering. 2000. Restoration of salt and brackish tidelands in southern New England: angiosperms, macroinvertebrates, fish and birds. In Concepts and controversies in tidal marsh ecology, ed. M.P. Weinstein and D.A. Kreeger, 845–858. Boston: Kluwer.Google Scholar
- Friedrichs, C.T. and J.E. Perry. 2001. Tidal salt marsh morphodynamics: a synthesis. Journal of Coastal Research 27: 7–37.Google Scholar
- Ganong, W. F. 1903. The vegetation of the Bay of Fundy salt and diked marshes: an ecological study. Botanical Gazette 36: 161–186, 280–302, 349–367, 429–455.Google Scholar
- Hanson, A. and L. Calkins. 1996. Wetlands of the Maritime Provinces: revised documentation for the wetlands inventory. Technical Report 267, 67 p. Canadian Wildlife Service, Atlantic Region, Sackville, New Brunswick.Google Scholar
- Kneib, R.T. 1994. Spatial pattern, spatial scale, and feeding in fishes. In Theory and Application in Fish Feeding Ecology, ed. D.J. Stouder, K.L. Fresh, R.J. Feller, and M. Duke, 171–185. Columbia: University of South Carolina Press.Google Scholar
- McGarigal, K., S. A. Cushman, M. C. Neel, and E. Ene. 2002. FRAGSTATS: Spatial Pattern Analysis Program for Categorical Maps (Version 3.3, available at http://www.umass.edu/landeco/research/fragstats/fragstats.html).
- Pestrong, R. 1965. The development of drainage patterns on tidal marshes. Stanford University publications 10(2): 1–85. School of Earth Sciences, Stanford University, Stanford.Google Scholar
Sources of unpublished material
- Department of Energy, Mines and Resources. 1950. [Black & white aerial photograph]. 1:20,000. Photo # A12676-94. Ottawa, Canada.Google Scholar
- Department of Energy, Mines and Resources. 1958. [Black & white aerial photograph]. 1:12,000. Photo # A16318-134. Ottawa, Canada.Google Scholar
- Department of Natural Resources. 1994. [2 Colour aerial photographs]. 1:12,500. Photos # DNRE 94502-111 and # DNRE 94503-103. Ottawa, Canada.Google Scholar
- Department of Natural Resources. 2001. [1 Colour aerial photograph]. 1:12,500. Photo # DNRE 01512-89. Ottawa, Canada.Google Scholar
- Nova Scotia Geomatics Centre. 1995. [1 Colour aerial photograph]. 1:10,000. Photo #DNRE 95001-11. Amherst, NS.Google Scholar