Seagrasses, which are protected locally and declining worldwide, have been proven elsewhere to provide valuable habitat for fishes and birds. But local studies documenting their value are surprisingly lacking; regional research has instead focused on salmon, which don’t linger in eelgrass meadows. This project will provide the overdue data that managers need to develop cost–benefit analyses and ecosystem-based protection and restoration strategies and to answer questions such as, “Why are some large fish less common in eelgrass than in open habitats?” It will document which fishes and birds use four habitat types—large meadows, smaller eelgrass patches, eelgrass-free patches, and the edge zones between—in five representative estuaries from northern Puget Sound to Willapa Bay. Purse seines and remote sensors will identify the fish present. Remote sensing and trained citizen-scientist birdwatchers will capture bird movements. Tethered prey will reveal predation pressure. Statistically analyzed and integrated, these observations should finally begin to fill the data gap.