Eelgrass ecosystem collapse and social-ecological regime shift driven by hydropower development and climate change

Area of Science:

• Ecology
• Environmental Science
• Indigenous Studies

Background:

• Global coastal habitats and wildlife are declining, affecting Indigenous Peoples.
• Hydropower development contributes to coastal habitat loss, posing challenges for carbon-neutral transitions.
• Understanding the combined impacts of climate change and hydropower is crucial for coastal mitigation.

Purpose of the Study:

• To analyze the collapse and recovery of a subarctic coastal social-ecological system.
• To attribute changes to hydroelectric development and climate change using a detection and attribution framework.
• To inform comprehensive assessments of hydropower developments.

Main Methods:

• Utilized historical observations, Indigenous knowledge, and scientific research.
• Applied a detection and attribution framework to assess ecological effects.
• Examined the social-ecological system of eelgrass, geese, and Cree in James Bay.

Main Results:

• Hydroelectric development (1978-1996) caused eelgrass declines and social-ecological system shifts.
• Climate-driven extreme events (1998 onwards) exacerbated losses, with feedbacks extending declines.
• Eelgrass recovery is hindered by poor water clarity, altered sediments, and hydrologic changes.

Conclusions:

• Hydroelectric development significantly impacted coastal ecosystems and Indigenous relationships with the environment.
• Climate change acts synergistically with development, complicating coastal habitat recovery.
• Future hydropower assessments must integrate coastal social-ecological dynamics and climate change impacts.