Estuarine buffering on the Pacific coast

Coastal salt marshes are among Earth’s most productive ecosystems and provide a number of ecosystem services, including interception of watershed-derived nitrogen (N) before it reaches nearshore oceans. Nitrogen pollution and climate change are two dominant drivers of global-change impacts on ecosystems, yet their interacting effects at the land-sea interface are poorly understood. We addressed how sea-level rise and anthropogenic N additions affect the salt marsh ecosystem.

Research goals

Our work addresses the need to adapt conservation strategies for salt marsh plants – in Pacific Coast estuaries – to a suite of environmental challenges, including climate change, land-use change, and nutrient pollution primarily from fertilizers. Linkages between land and sea are too often overlooked, and our focus on these connections will lead to improved conservation priorities. Coastal salt marsh ecosystems are increasingly rare, worth saving, and squeezed in the middle of human land- and ocean-use choices. They contribute significantly to regulation of nutrient runoff from agriculture, buffer storm surges, and provide crucial wildlife habitat. We on the ecosystem service, delivered by salt marshes, of intercepting land-derived nitrogen pollution to prevent environmental problems in the ocean, such as harmful algal blooms and low-oxygen “dead zones.” Therefore, we investigate native salt marsh plants in an ecological framework that relates ecosystem function to ecosystem services, the benefits humans receive from natural systems.

Elkhorn Slough

Our research questions in Elkhorn Slough National Estuarine Research Reserve are:

    1. How do the synergistic effects of sea-level rise due to climate change and anthropogenic nitrogen additions affect salt marsh plants?
    2. How much added nitrogen can salt marsh plants intercept under conditions of chronic nutrient addition?
    3. Over the next century, how might climate change affect the ability of Pacific coast wetlands to provide valued water filtration if salt marshes are converted to mudflats?

Project participants: Joanna Nelson, Erika Zavaleta

Elkhorn Slough