706
projects; (3) monitoring with a research focus ensures observation and quantification of unexpected phenomena; and (4) the design process used, including the
hydrodynamic model, was successful and can be used again for similar situations.
Keywords Bay of Fundy • Ice • Macrotidal • Restoration • Salt marsh • Salt pool •
Sedimentation • Spartina
21.1 Introduction
21.1.1 Environmental Context
The Atlantic coast of North America is an old coast characterized by highly eroded
mountain ranges and, at lower latitudes, extensive sedimentary shorelines (Bally
and Palmer 1989; Bertness 2007). Salt marshes are a dominant habitat south of New
England (Bertness 2007). At higher latitudes, past glacial scour moved much of the
sediments offshore, leaving rocky shores as the dominant coastal habitat (Maine,
Atlantic coast of Nova Scotia, Newfoundland). An exception is the Bay of Fundy
(Fig. 21.1). In the upper Bay of Fundy (along both arms, Chignecto Bay and Minas
Basin), tidal flats and salt marshes are the dominant habitat. For example, on the
New Brunswick coast of Chignecto Bay, tidal flats and salt marsh comprise 92% of
the coastline area (58% and 34%, respectively; New Brunswick Department of
Natural Resources unpublished data).
The soft-sediment habitats in the Bay of Fundy are the result of very large, semidiurnal tides (some of the highest in the world, frequently over 14 m amplitude in
the upper Bay) and consequent strong eroding tidal currents on surrounding cliffs of
friable sedimentary rock, primarily shale and siltstone in Chignecto Bay (Desplanque
and Mossman 2004). The upper Bay also has very high suspended sediment concentration in the water, typically 300 mg/L or higher (Amos and Tee 1989).
The Bay of Fundy, being in the north temperate zone, experiences winter disturbance including annual freezing and ice scour along the coastline, but not in the
open water (Desplanque and Mossman 2004; Drolet et al. 2013; Gordon and
Desplanque 1983). In salt marshes, the strong seasonality means that plants become
senescent and die in the fall. Dead grass stems and blades either get sheared in wintertime, forming wrack (mats of dead plant matter), or get crushed and eventually
buried forming peat (Baerlocher and Moulton 1999; Redfield 1972). Winter ice not
only scours the surface of the salt marsh (Ewanchuk and Bertness 2003), but also
damages its seaward edge, leaving it in a constant state of recovery. Furthermore,
ice blocks move sediment and marsh turf around, which depending on currents and
wind are often deposited high on the shoreline, including in the high marsh (Argow
et al. 2011; Ollerhead et al. 1999; Redfield 1972).
Because of cool summer air temperatures and intense water movement, the saltwater cordgrass Spartina alterniflora, the bioengineer species of salt marshes along
L.K. Boone et al.
projects; (3) monitoring with a research focus ensures observation and quantification of unexpected phenomena; and (4) the design process used, including the
hydrodynamic model, was successful and can be used again for similar situations.
Keywords Bay of Fundy • Ice • Macrotidal • Restoration • Salt marsh • Salt pool •
Sedimentation • Spartina
21.1 Introduction
21.1.1 Environmental Context
The Atlantic coast of North America is an old coast characterized by highly eroded
mountain ranges and, at lower latitudes, extensive sedimentary shorelines (Bally
and Palmer 1989; Bertness 2007). Salt marshes are a dominant habitat south of New
England (Bertness 2007). At higher latitudes, past glacial scour moved much of the
sediments offshore, leaving rocky shores as the dominant coastal habitat (Maine,
Atlantic coast of Nova Scotia, Newfoundland). An exception is the Bay of Fundy
(Fig. 21.1). In the upper Bay of Fundy (along both arms, Chignecto Bay and Minas
Basin), tidal flats and salt marshes are the dominant habitat. For example, on the
New Brunswick coast of Chignecto Bay, tidal flats and salt marsh comprise 92% of
the coastline area (58% and 34%, respectively; New Brunswick Department of
Natural Resources unpublished data).
The soft-sediment habitats in the Bay of Fundy are the result of very large, semidiurnal tides (some of the highest in the world, frequently over 14 m amplitude in
the upper Bay) and consequent strong eroding tidal currents on surrounding cliffs of
friable sedimentary rock, primarily shale and siltstone in Chignecto Bay (Desplanque
and Mossman 2004). The upper Bay also has very high suspended sediment concentration in the water, typically 300 mg/L or higher (Amos and Tee 1989).
The Bay of Fundy, being in the north temperate zone, experiences winter disturbance including annual freezing and ice scour along the coastline, but not in the
open water (Desplanque and Mossman 2004; Drolet et al. 2013; Gordon and
Desplanque 1983). In salt marshes, the strong seasonality means that plants become
senescent and die in the fall. Dead grass stems and blades either get sheared in wintertime, forming wrack (mats of dead plant matter), or get crushed and eventually
buried forming peat (Baerlocher and Moulton 1999; Redfield 1972). Winter ice not
only scours the surface of the salt marsh (Ewanchuk and Bertness 2003), but also
damages its seaward edge, leaving it in a constant state of recovery. Furthermore,
ice blocks move sediment and marsh turf around, which depending on currents and
wind are often deposited high on the shoreline, including in the high marsh (Argow
et al. 2011; Ollerhead et al. 1999; Redfield 1972).
Because of cool summer air temperatures and intense water movement, the saltwater cordgrass Spartina alterniflora, the bioengineer species of salt marshes along
L.K. Boone et al.