Aquatic Species Assessment Tool (ASAT)

Aquatic Species Assessment Tool (ASAT)

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Project Goal:

The Aquatic Species Assessment Tool (ASAT) will provide an integrated quantitative framework for assessing the impact of management actions on salmonids and other sensitive species that depend on the estuary for their lifecycle.

ASAT Tool developed

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Project Stages


Conceptual Design



Estimated Completion Date:

Project Funders

Wildlife Conservation Board

Fish Affected:

Project Description

Salmonids are among the species most sensitive to temperature and poor water quality, and migrate through freshwater, estuaries, and saltwater multiple times in their lives. Therefore, they make excellent indicators of overall watershed health and function. Current research shows 11 of the remaining 21 anadromous salmonids in California are at critical risk of extinction in the next 50 years under present trends. Estuaries are especially important to the survival of juvenile salmonids given the important role they serve as critical feeding and nursery habitats, increasing the number of salmonids that survive to adulthood and return to spawn.

In light of these factors, CalTrout is developing a new estuary assessment and management tool in order to understand and protect ecologically sensitive aquatic species such as endangered salmonids. The goal is to enhance biodiversity in estuaries and build ecosystem resilience to protect them from the impacts of climate change and sea level rise in California.

The Aquatic Species Assessment Tool (ASAT) tool will use ecological inputs to predict the impact of management actions on aquatic species communities. Inputs considered include water quality, habitat and food web complexity, and species' seasonal usage for threatened and endangered species such as salmon and steelhead, tidewater goby, and Pacific lamprey. Results from the tool can be used to predict responses of aquatic species to changes in their environment in an integrated way. The ASAT will provide a user-friendly tool for resource managers, regulatory agencies, and restoration practitioners to inform decisions in a multi-species context about estuary restoration and management actions.

Millions of dollars are allocated to tidal wetland and related restoration projects in California annually, yet the benefits to sensitive estuarine aquatic species remain uncharacterized. The Aquatic Species Assessment Tool (ASAT) addresses this problem by generating a framework of estuarine habitat values for an assemblage of listed fishes and guidance on how to achieve them. Based on physiological requirements of target aquatic species, as well as their dependence on certain habitat characteristics and their temporal presence, the ASAT tool will allow the comparison of impacts to specific listed and other estuarine aquatic species upon implementation of specific management actions. Building on CDFW’s Areas of Conservation Emphasis, this project establishes the current knowledge of water quality, vegetative, and food-web habitat parameters necessary to increase resilience for an assemblage of aquatic listed species in a changing climate.

Project Partners:

University of California, Berkeley
Technical Advisory Committee
ASAT end-users

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