The Northwest Climate Adaptation Science Center (NW CASC) organizes an annual Deep Dive into an emerging climate risk. We convene researchers, practitioners and students to assess the state of knowledge and practice associated with managing that risk. Each Deep Dive aims to facilitate community development of an Actionable Science Agenda that outlines knowledge gaps and research needs and identifies opportunities to advance adaptation by linking science and practice.

Managing Inland Migration of Coastal Habitats in Response to Sea Level Rise

Source: Dan Meyers, Unsplash, Public Domain

The Northwest Climate Adaptation Science Center’s 2023 Deep Dive will convene Northwest scientists, natural resource managers and communities to collaboratively review what is known about coastal squeeze in a changing climate and to identify research and capacity needs for building resilience of shoreline and estuarine habitats in a changing climate.

Shorelines and estuaries in Washington and Oregon host some of the region’s most critically important habitats. As climate change drives sea levels higher, coastal habitats may adapt by migrating inland. This inland shift is challenged, however, by the presence of human-made and natural barriers, which may result in considerable declines in coastal habitats and associated fish and wildlife populations. This is commonly known as ‘coastal squeeze’.

Barriers to inland habitat migration can arise in a number of ways. In the Northwest, coastal habitats are often adjacent to some of the most developed areas in the region, with the footprint of built infrastructure — including sea walls, roads, residential and commercial buildings, and port facilities — continuing to expand along coastlines. Topographical features also impose limits, as well as other barriers such as levees that may act as ‘soft’ impediments.

Source: Mick Thompson

Other factors relating to the sensitivity and exposure of coastal habitats may also be considered when assessing the impacts of coastal squeeze. The pace of sea level rise in the Pacific Northwest is expected to be highly variable around the region due to tectonic influences on land movement. Some habitat types may be more resilient to changes in sea level than others, or be more uniquely positioned to move inland due to geographic factors. Additionally, the disappearance of some coastal habitat types may increase the exposure of neighboring lands and infrastructure to impacts of sea level rise and other hazards.

Scientists and natural resource managers require a greater understanding of the threat posed by coastal squeeze in the Northwest. Similarly, management and policy options are needed to support the resilience of Northwest shoreline and estuarine habitats. To help meet this need, the Northwest Climate Adaptation Science Center’s 2023 Deep Dive will facilitate the co-creation of a regional synthesis that describes the state of the science, management and human dimensions of coastal squeeze and identifies key needs for addressing gaps in knowledge and capacity. By engaging a diverse group of scientists, managers and other relevant stakeholders in this process, the Deep Dive aims to enhance the region’s capacity and community of practice for robust management of coastal squeeze.

Deep Dive Summary Products

The summary report describes the key findings and the co-developed actionable science agenda that emerged from the Deep Dive, while the key findings document provides a high-level overview of the Deep Dive outcomes.

Deep Dive Syntheses

The synthesis reports describe results of the three Deep Dive working groups that contributed to the key findings and include citations, survey results and other supporting evidence.

Deep Dive Resources

Resources developed through the Deep Dive include a tools database, which includes links and descriptions of over 30 different tools potentially useful in coastal squeeze research and management, as well as a list proposed of project ideas generated by 2023 Deep Dive workshop participants to help address the research needs described in this report.