Beamer, E., Henderson, R. and Wolf, K., 2011. Measurements of Landscape Connectivity for Blind Tidal Channel Networks and Selected Pocket Estuary Outlets within the Skagit Tidal Delta and Bay. Skagit River System Cooperative, La Conner, WA. pp. 12.

Within the delta and nearshore ecosystems of the Skagit River, Beamer et al. (2005) used habitat connectivity as an attribute to help predict the use of specific habitats for Chinook salmon recovery planning. Landscape connectivity was defined as a function of both the length and the complexity of the pathway that juvenile Chinook salmon must follow to access certain types of habitat, like blind tidal channels in the Skagit delta or pocket estuaries in adjacent nearshore areas. Habitat connectivity decreases as the complexity of the route fish must swim increases and as the distance the fish must swim increases. Within the Skagit delta, the complexity of the route fish must take to find habitat was determined by the delta distributary channel bifurcation order. Beamer et al. (2005) show results from 2003, when the Skagit River had an outmigration population size of 5,500,000 juvenile Chinook salmon. In this year, landscape connectivity explained 68% of the variation in seasonal density of Chinook salmon at monitored sites within the Skagit estuary (see pages 20-21 of Beamer et al. 2005). As a result, the Skagit Chinook Recovery Plan (SRSC and WDFW 2005) states that Chinook salmon population recovery should include:
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Restoration of habitat connectivity within the delta because of the loss of historic connectivity due to human-caused blocking of distributary channels, and
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Application of concepts of habitat connectivity as a means to prioritize and predict outcomes of specific delta and pocket estuary restoration sites.
Landscape connectivity measurements for habitat throughout the Skagit estuary can be useful to salmon recovery managers interested in planning and tracking implementation progress of restoration, as well as to researchers conducting juvenile Chinook salmon monitoring (e.g., Greene and Beamer 2006). Thus, we created a GIS layer of point data representing all outlet mouth locations of blind tidal channel networks within the Skagit tidal delta as of year 2000, and selected pocket estuaries within adjacent nearshore areas (e.g., Skagit Bay or Padilla Bay). For each point, we calculated landscape connectivity