Mermaid Creek Salt Marsh Restoration
The Mermaid Creek Salt Marsh is a small pickleweed (Salicornia pacifica) and salt grass (Distichlis spicata) dominated delta located at the mouth of Mermaid Creek on the southeast end of Roberts Bay, Sidney, British Columbia in the Traditional Territories of the Tseycum Nation. This regionally rare coastal ecosystem is small but mighty in terms of its ecosystem productivity as well as provision of ecosystem services. Salt marshes provide blue carbon sequestration, important nutrients, water filtration, productive habitats for fish and wildlife, and natural protection for upland areas from strong storms through the buffering of wave energy.
These important coastal ecosystems are often the most desirable for agriculture, fishing and hunting, industrial practices, transportation infrastructure, habitation, and development. As a result of this, these critical coastal ecosystems are under threat as they have been disproportionately lost, degraded, or modified over the past century (some estimates put this loss upwards of 70% in the Salish Sea). The Roberts Bay Blue Carbon Study commissioned by SeaChange Marine Conservation Society (SeaChange) and Peninsula Streams and Shorelines (PSS) completed in 2021 by Coastal and Ocean Resources Institute (CORI) found that the Mermaid Creek Delta marsh had experienced a significant decline of over 70% over the last 60 years. The past two years have seen a significant acceleration of erosion rates with ~30% of marsh area eroding annually (CORI 2022). To better understand the causes and dynamics of this and to provide a concept for a solution, we commissioned another study completed by DHI’s coastal engineers in 2022.
The DHI study (2022) provides a summary of wave conditions in Roberts Bay and highlights several likely contributing factors to the decline of the Mermaid Creek Salt Marsh including 1.) the historical modification of natural sources and conduits of sediment being delivered to the marsh, both from Mermaid Creek itself as well as from the marine environment 2.) increased forces of erosion driven by climate change including intense storm surges and Sea Level Rise (SLR). Importantly, the burial and incorporation of Mermaid Creek into the Town of Sidney’s stormwater system cutoff sediments delivered by Mermaid Creek to the delta. Additionally, modified shorelines, including shoreline hard armouring, disrupt the dynamic nature of coastal sediment processes including erosion, transport, and wave structure in the bay. The report concluded that if action is not taken there is a large likelihood this important ecosystem and habitat will be lost with ecological consequence to Roberts Bay including loss and diminishment of the ecosystem services such as stormwater filtration, blue carbon sequestration, shoreline stabilization, sustainable beach nourishment, shoreline protection, pollination, aesthetic and cultural values and the productive habitats for fish and wildlife.
Project Funding and Treatments:
PSS and our partners SeaChange Marine Conservation Society Stewardship in close collaboration with Tseycum Marine Stewardship have secured funding to deliver the much larger restorative concept provided by DHI and finalised by McElhanney that will address the restoration of the lower salt marsh on the beach. This work is funded by Environment and Climate Change Canada, the World Wildlife Fund, North America Partnership for Environmental Community Action, The Real Estate Foundation of BC, the Pacific Salmon Foundation, and The Town of Sidney.
Phase 1 (Sept 2022-April 2023):
This effort focused on the upper marsh area of Mermaid Creek Estuary. To help retain the rapidly eroding banks of Mermaid Creek Estuary and expand the upper marsh portion of the marsh, ecocultural fencing was installed on the banks of the creek in September 2022. PSS staff were joined by Roberts Bay Residents’ volunteers and the Guardians of Mid Island Estuaries to install alder and willow fencing to help stabilise eroded materials and protect Lyngby’s Sedge out-plantings from Canada goose grazing which were planted by volunteers and members of Tseycum Marine on March 14th and 15th, 2023.
Phase 2 (delayed until late August - TBD):
PSS and our partners SeaChange Marine Conservation Society Stewardship have secured funding to deliver the much larger restorative concept provided by DHI and finalized by McElhanney with our collaborators Tseycum Marine Stewardship that will address the restoration of the lower salt marsh on the beach.
The Roberts Bay Salt Marsh Restoration Project will involve:
- Creating ~ 1m high rock crescent clustered headlands ~20 m seaward of the existing marsh edge to attenuate wave energy from intensifying storm surges;
- Nourishment of the area between the existing marsh edge and the newly formed headlands with ~ 4000 tons of imported marsh and beach sediments; and,
- Planting and stabilising the restored marsh area with pickleweed and salt grass (Spring 2024)
- Adaptive Management / Monitoring of elevations, materials, and plantings (ongoing)
Construction will begin once all the necessary permits are in place, including permits and permissions from: The Tseycum Nation, Town of Sidney, British Columbia Environmental and Heritage Ministries, Fisheries and Oceans Canada (DFO), Ministry of Transportation, and the Canadian Wildlife Service. Access for trucks carrying materials and machinery will be at the terminal end of 5th street. Flagging and traffic control will be onsite to ensure safety and efficacy of through traffic. Access to the beach during construction via this access will be maintained as much as possible but temporary closures are expected.
Through the active restoration of the lower marsh through the construction of small headlands, expanding and elevating the area of the marsh through sediment replenishment, and through planting native marsh species, we will be increasing and enhancing:
- Carbon sequestration capacity of the marsh
- Nature-based shoreline protection from projected increase in storm surges and sea level rise
- Vital habitat for fish, birds, invertebrates, bivalves, and other wildlife
As engineered drawings and updates become available they will be posted here.
Open House - Held on April 5th 2023 7:00-8:30 pm
Location: Shoal Centre Auditorium B
Project team members and display materials were available for engagement, to learn more about the project and ask questions.
May 6th Site Tour - Roberts Bay Walk About
Met on 5th St. kayak launch at 11:30 Saturday May 6th.
June Open House - Online, (TBD) Zoom invites to be sent out closer to date
Construction: Delayed - dates to be confirmed
- Construction for this project will take place will occur during this period. This will involve increased traffic and noise on the beach and in the Robert’s Bay neighbourhood as large trucks deliver material to site and machinery move the material to grade. Access to the site will be through 5th St. and subcontracted flaggers will be onsite to ensure smooth and safe traffic control. Expect temporary closures and delays.
Responses to Questions from Roberts Bay Neighbours
RB Neighbours Questions and Concerns and Responses.docx
Why are you doing this?
Due to changes in the Watershed and Roberts Bay, Mermaid Creek is rapidly eroding, and if nothing is done this important ecosystem will be lost.
What will restoration involve? How can I learn more?
The restoration design concept involves importing ~7000 tons of sand and gravel marsh nourishment material over a 3-week period via 5th St. Please head to our webpage via the QR or peninsulastreams.ca on the front of this brochure for updates and details.
What permits are needed for this work?
This work will be permitted by all relevant Federal, Regional and Local regulatory bodies including a project review from the Department of Fisheries and Oceans, a permit for crown tenure through the Nature Based Shoreline Protection, review from Transport Canada and the Canadian Wildlife Service. Archaeological surveys will be completed and any relevant permits acquired under the Heritage Act. Infaunal surveys have been completed by project biologists as well as an environmental impact assessment as part of this process. All proposed and required mitigations will be followed strictly with biological monitors onsite during construction. This includes inspections for leaks, biodegradable lubricants and hydraulics, and all necessary spill kits and plans. Permissions have also been granted from the Tseycum Nation as well as the Town of Sidney.
Why is there fencing in Mermaid Creek's estuary?
Eco-cultural fencing is a bio-engineering technique to help stabilize eroded materials while creating a protective plant enclosure for Lyngby’s Sedge plantings which were planted in March 2023.
Will there be a bridge and path for pedestrians?
There will be no bridge for pedestrians but some large flat rocks will be added to facilitate crossing Mermaid Creek at higher tides.
If you have more questions or concerns please consider attending our open houses or email Project Coordinator Kyle Armstrong (firstname.lastname@example.org)
DHI - Roberts Bay Report FINAL 20221129
McElhanney Engineering Report:
2023-05-02 McElhanney - Roberts Bay Tidal Marsh Restoration - DRAFT
Webinar with Robert’s Bay Residents, Peninsula Streams, SeaChange and CORI:
Radio Interview with Peninsula Stream’s Kyle Armstrong:
Resilient Shorelines Webinar with Peninsula Stream’s and Pacific Salmon Foundation:
In the news:
Sidney offering financial support for this project February 2023:
Eco-cultural fencing project in the news October 2022:
Figure 1. Mermaid Creek Salt Marsh, looking out into Roberts Bay in Sidney, BC.
Figure 2. Aerial images of mermaid creek delta, outlining salt marsh regression from 1964-2022. Note→ Over 70% of the marsh has been lost since 1960 and annual rates are increasing to upwards of 30% per year in the last two years.
Figure 3. Mermaid Creek Eco-cultural Fencing, completed September 2022 and subsequent planting March 2023. → Note: 500 Lyngby’s Sedges were planted in planting areas throughout the upper marsh. This grass-like species actively builds the marsh by stilling water with its long vegetation allowing sediment to deposit which it then fixes with its roots which overtime rebuilds marsh banks.
Figure 4. DHI Technical Coastal Engineering Salt Marsh Restoration Concept Design. Note→ This design is being finalised into engineered drawings by McElhanney who have been hired as coastal engineers to deliver the project. The pedestrian crossing will be informal rock structures to increase connectivity for pedestrians but will not be a formal bridge.