744
involving key stakeholders to develop an agreed-upon approach, successful projects
in our area (e.g., Bowron et al. 2012; this study) demonstrate that salt marsh restoration is a viable option that deserves serious consideration.
21.6 Conclusions
The project is still in a race against time. The old dike continues to erode at a relatively rapid pace. To protect the new dike, a healthy salt marsh needs to develop in
the restoration cells. This seems to be happening in the NW cell, where percent
cover by salt marsh vegetation is extensive and the surface is continuing to accrete.
In the SE cell, the situation is less certain; plant spread has been slower and overall
plant percent cover is less, most likely because of a lower initial surface elevation
and high rate of sediment deposition resulting in a soft, unconsolidated surface. This
said, sediment continues to be deposited; so, it is a matter of waiting to see if salt
marsh development continues in the SE cell in the face of increased exposure to
waves and ice now that the old dike is largely eroded and breached in numerous
places. Salt marsh recovery is not inevitable, and there are cases in other geographic
locations of sites becoming mudflat (French et al. 2000).
There is not much that can be done now but continue to monitor the project and
learn as many lessons as possible. We will continue to employ an investigative or
research approach to monitoring, to ensure that we do not miss important changes
or events. The failure of the old dike was inevitable and now it is a matter of waiting
to see what type of salt marsh develops in front of the new dike on the foundation
that has been deposited over the past 5 years and learning from the ecosystem differences that are appearing between the SE and NW cells.
This said, monitoring the project has improved our knowledge of the ecology of
Maritime Canadian salt marshes and added to the growing literature on salt marsh
restoration worldwide. Restorations in our region have historically been studied
passively on abandoned agricultural sites (e.g., Byer and Chmura 2007). More
recently, the focus has shifted to monitoring deliberate, managed projects (Bowron
et al. 2009, 2012; van Proosdji et al. 2010). The Bay of Fundy provides an excellent
area for future salt marsh restoration projects due to its high suspended sediment
content, extensive tidal flushing, and historical land use patterns. Worldwide historical salt marsh habitat loss has been estimated at 65% (Bromberg Gedan and Silliman
2009). Barring expensive interventions, it is inevitable that rising seas will flood
much that was previously reclaimed. Salt marsh restoration is a means to make the
most of the reality that confronts us by restoring the natural aesthetic and returning
valuable ecosystem services to our coasts while protecting human infrastructure at
the same time.
Acknowledgments We thank Rhiana Bams, Allie Byrne, Vicki Connors, Kristie Duncan, Andrew
Ollerhead, Léa Olsen, Rosie Smith, Cindy Spicer and Norma Jean Worden-Rogers associated with
Mount Allison University for field assistance; Cody Alderson, Allison Dykstra, Lionel Hayter,
L.K. Boone et al.
involving key stakeholders to develop an agreed-upon approach, successful projects
in our area (e.g., Bowron et al. 2012; this study) demonstrate that salt marsh restoration is a viable option that deserves serious consideration.
21.6 Conclusions
The project is still in a race against time. The old dike continues to erode at a relatively rapid pace. To protect the new dike, a healthy salt marsh needs to develop in
the restoration cells. This seems to be happening in the NW cell, where percent
cover by salt marsh vegetation is extensive and the surface is continuing to accrete.
In the SE cell, the situation is less certain; plant spread has been slower and overall
plant percent cover is less, most likely because of a lower initial surface elevation
and high rate of sediment deposition resulting in a soft, unconsolidated surface. This
said, sediment continues to be deposited; so, it is a matter of waiting to see if salt
marsh development continues in the SE cell in the face of increased exposure to
waves and ice now that the old dike is largely eroded and breached in numerous
places. Salt marsh recovery is not inevitable, and there are cases in other geographic
locations of sites becoming mudflat (French et al. 2000).
There is not much that can be done now but continue to monitor the project and
learn as many lessons as possible. We will continue to employ an investigative or
research approach to monitoring, to ensure that we do not miss important changes
or events. The failure of the old dike was inevitable and now it is a matter of waiting
to see what type of salt marsh develops in front of the new dike on the foundation
that has been deposited over the past 5 years and learning from the ecosystem differences that are appearing between the SE and NW cells.
This said, monitoring the project has improved our knowledge of the ecology of
Maritime Canadian salt marshes and added to the growing literature on salt marsh
restoration worldwide. Restorations in our region have historically been studied
passively on abandoned agricultural sites (e.g., Byer and Chmura 2007). More
recently, the focus has shifted to monitoring deliberate, managed projects (Bowron
et al. 2009, 2012; van Proosdji et al. 2010). The Bay of Fundy provides an excellent
area for future salt marsh restoration projects due to its high suspended sediment
content, extensive tidal flushing, and historical land use patterns. Worldwide historical salt marsh habitat loss has been estimated at 65% (Bromberg Gedan and Silliman
2009). Barring expensive interventions, it is inevitable that rising seas will flood
much that was previously reclaimed. Salt marsh restoration is a means to make the
most of the reality that confronts us by restoring the natural aesthetic and returning
valuable ecosystem services to our coasts while protecting human infrastructure at
the same time.
Acknowledgments We thank Rhiana Bams, Allie Byrne, Vicki Connors, Kristie Duncan, Andrew
Ollerhead, Léa Olsen, Rosie Smith, Cindy Spicer and Norma Jean Worden-Rogers associated with
Mount Allison University for field assistance; Cody Alderson, Allison Dykstra, Lionel Hayter,
L.K. Boone et al.