Slater, G., 2004. Waterbird abundance and habitat use in estuarine and agricultural habitats of the Skagit and Stillaguamish River deltas. Ecostudies Institute, Mount Vernon, WA. pp. 95.

Coastal estuarine wetlands, with their integrated complement of tidal, nontidal, and
riverine wetland habitats, are reservoirs for significant amounts of biodiversity in North America.
Driven mostly by hydrological forces, these connected heterogeneous wetlands perform many
valuable ecosystem functions and services, suc h as filtration of pollutants, retention of nutrients,
and critical nursery and rearing habitat for many wildlife species, including commerciallyimportant
fish (Mitsch and Gosselink 2000). Yet, significant areas of coastal wetland across
North America have been lost, and continue to face increasing threats from human development
(Gosselink and Baumann 1980, Mitsch and Gosselink 2000).
Coastal estuarine wetlands in the Puget Sound Trough of the Pacific Northwest, with its
extensive network of rivers, have not fared better, and this is particularly evident in the Greater
Skagit River Delta (GSD; Skagit, Stillaguamish, and Samish River). The GSD’s fertile wetlands
and wide floodplain have mostly been converted to agriculture, resulting in the loss of most tidal
wetlands and all of its freshwater wetlands by the early 1900’s (Collins 2000).
The loss and degradation of wetlands in the GSD has had a significant negative impact to
native biodiversity, including the decline of many important fisheries, most notably salmon
(Simenstad and Cordell 2000). Large populations of waterfowl and shorebirds used the tidal
flats and estuarine marshlands during the winter and migration periods prior to Euro-American
settlement. Although little is known about the historic composition and extent of these nonbreeding
communities, it is generally accepted that populations have declined significantly (Ball
et al. 1989, Drut and Buchanan 2002).
With the increasing recognition of the ecological services and functions that wetland
ecosystems provide in the GSD, the decline of many wetland-dependent species, and the recent
federal listing of the economically and culturally-important Chinook Salmon, many
organizations and agencies are working to design and implement wetland restoration and wildlife
conservation plans. In particular, restoration of estuarine habitats, especially tidal marsh, for
salmon has gained substantial political momentum. Yet, some managers are concerned about
potential trade-offs that may exist between management for fisheries and waterbirds, especially
waterfowl.