The St. Lawrence Estuary and Gulf have been occupied for more than 10.000 years and are one of the cradles of the settlement of the Canadian territory. The successive occupations of their coasts have left traces that today constitute a rich archaeological archive. However, a significant part of this precious heritage is affected by coastal erosion, which is accelerating due to climate change and the anthropization of the banks. Its management requires difficult compromises between data acquisition and the protection of fragile environments. Regular monitoring would allow the documentation of this heritage without accelerating its erosion, but it would require an investment that archaeologists alone cannot provide, hence the interest of calling in the public. However, a citizen science approach requires methods and protocols that are compatible with current regulations, can deliver quality data and allow for optimal management of the archaeological resource. This paper discusses and compares projects that have involved the public in documenting coastal archaeological heritage at risk in North America and Europe. Their experience will contribute to the development of a pilot project in the St. Lawrence Estuary to be implemented in the summer of 2025.

Many studies have documented the threats of environmental changes caused by climate change to terrestrial and shoreline archaeological sites. However, there has been less investigation of the potential impacts of climate change on underwater cultural heritage. Divers from the Shipwreck Preservation Society of Newfoundland & Labrador (SPSNL) returned to the site of a 17^th-century and a 20^th-century shipwreck near Isle aux Morts, Newfoundland, to assess the possible impacts of hurricane Fiona. Hurricane Fiona struck southwest Newfoundland on September 24, 2022 and was the most powerful post-tropical storm ever recorded in Atlantic Canada. Maximum wind speeds were 134 km/hr and waves were 15 m high at nearby Port aux Basques, NL. The 17^th-century Isle aux Morts shipwreck (CjBs-01) is only 10 m deep and is mostly buried in sand. The wreck site was the same as when it was mapped in 1983 and appeared to be undamaged by Fiona. In contrast, the 20^th-century Staalbas shipwreck appeared to have sustained significant damage from Fiona, despite its greater depth of 15 m. Local bathymetry (seabed topography) seems to play an important role in sheltering or exposing shipwrecks to damaging wave action during severe storm events.

It has been 7 years since a destructive hurricane-force windstorm swept through the northeast Pacific coast of British Columbia, impacting an ancestral Khungit Haida Heritage Site and UNESCO World Heritage Site, SG̱ang Gwaay Llnagaay (Wailing Island Village). The storm destruction triggered a collaborative mitigation project co-managed by Haida partners and Parks Canada. Archaeological projects in sensitive cultural areas like SG̱ang Gwaay Llnagaay are rare, and in this case, was only considered acceptable because the storm ‘broke ground’ exposing and displacing cultural belongings and sediments, and damaging Village architecture. As such, this project has provided an opportunity to further understand Haida archaeological history and deep-time landscape use on the island, spanning from the time of forced evacuation in the late 1880s to nearly 10,000 years ago. As the archaeological component of the project wraps up this year, we have an opportunity to discuss the results of our research, reflect on lessons learned, and share how we believe the response to the climatic event at SG̱ang Gwaay was successful because the collaborative framework held Indigenous-led stewardship at the forefront, with archaeology supporting by gathering information that could assist community decision making in long-term climate resilience planning.

Climate-driven geohazards are transforming the continental interior of Canada. These transformations are particularly evident in northern and alpine areas where climate-sensitive landscapes are destabilized by increased intensity of permafrost thaw, wildfires, floods and extreme weather events. Many sedimentary archives that contain linked multi-millennial archaeological and paleoenvironmental records are being lost (e.g., ice patches, aeolian deposits, floodplain deposits). These ecocultural records are our main sources of information about past environmental and human responses to shifts in climate. They are foundational input for models that guide climate change mitigation, adaptation and resiliency policy. Loss of these records has a negative impact on our ability to navigate the current climate crisis. However, the character and magnitude of this impact is not well understood because there has been limited study of climate risk to ecocultural archives. This presentation proposes a landscape approach to climate-risk management of ecocultural archives using Rocky Mountain paleosols as a case study.