Abstract
<title>Abstract</title> <p>Landscape connectivity is the extent to which the structure of a habitat facilitates the movement of biological units through the landscape itself. Throughout the Pacific Northwest, outmigrating natural origin Chinook Salmon fry rear in river delta channels to grow and strengthen before continuing seaward. This vital habitat has been fragmented in modern times as channels have been modified for agricultural and urban expansion, making habitat once accessible to salmon now less connected to riverine and tidal processes. Previous studies within Puget Sound have illustrated patterns showing higher juvenile Chinook Salmon densities rearing within more highly connected habitat. We test this relationship between fish density and landscape connectivity within the Skagit River delta by assessing changes in densities over the formation of a major river avulsion which coincided with a long-term juvenile salmon monitoring program. Results indicate a consistent relationship between landscape connectivity and juvenile densities across shifting connectivity gradients, making this the first study to experimentally demonstrate the functional relationship between landscape connectivity and delta habitat usage. Results underscore the importance of increased connectivity when considering restoration objectives and provide evidence that Chinook Salmon densities will respond to restoration of landscape connectivity in a predictable way.</p>