Beamer, E., Greene, C., Brown, E., Wolf, K., Rice, C. and Henderson, R., 2016. An Assessment of Juvenile Chinook Salmon Population Structure and Dynamics in the Nooksack Estuary and Bellingham Bay Shoreline, 2003-2015. Skagit River System Cooperative, La Conner, WA. pp. 165.

Puget Sound Chinook salmon were listed as Threatened under the Endangered Species Act (ESA) in 1999. In response, local watersheds throughout Puget Sound created recovery plan chapters which were submitted to the National Oceanic and Atmospheric Administration in 2005. The 2005 Water Resource Inventory Area (WRIA) 1 Salmonid Recovery Plan included recovery actions for the Nooksack River’s estuary and nearshore. However, a lack of specific analysis of Nooksack juvenile Chinook salmon population dynamics led to uncertainties in determining the importance and priority of habitat actions within the estuary or nearshore compared to recovery actions within other parts of the Nooksack River basin. The City of Bellingham, recognizing the importance of filling this information gap, commissioned this study in partnership with Bellingham Bay Action Team and Lummi Nation to investigate the role of estuarine and nearshore marine habitats on Nooksack early Chinook productivity and abundance.
Specifically, this study fills knowledge gaps on juvenile Chinook salmon population structure, origin, and performance within the Nooksack tidal delta and Bellingham Bay nearshore habitats. Population structure refers to identifying temporal habitat use by natural and hatchery origin juvenile Chinook salmon, including at what size and relative abundance they occupy habitats. Origin refers to identifying which rivers or hatchery release sites juvenile Chinook are coming from. Performance refers to pressures on the juvenile Chinook population that limit abundance or productivity. In this study we identify whether natural origin juvenile Chinook are experiencing density dependence in the Nooksack tidal delta under contemporary habitat conditions and outmigration sizes. We also examine the relationship of food availability and habitat specific growth of juvenile Chinook that rear in Nooksack tidal delta and Bellingham Bay pocket estuary habitats.
This study quantifies habitat conditions of the Nooksack tidal delta and connectivity of habitats within and between the Nooksack tidal delta and Bellingham Bay nearshore to assist in analyses of juvenile Chinook salmon population dynamics and habitat preference. We utilized existing datasets provided by the Lummi Nation of Nooksack River juvenile Chinook outmigration over the years 2005-2015 and beach seine catches of juvenile Chinook salmon in the Nooksack tidal delta and Bellingham Bay nearshore over years 2003-2013. As part of this study we collected beach seine data of juvenile Chinook salmon in the Nooksack tidal delta and Bellingham Bay nearshore in 2014 and 2015. Overall, these extensive data are more than adequate to understand the role of estuarine and nearshore marine habitats on Nooksack early Chinook productivity and abundance. Below we highlight some of the study’s most important findings and recommendations.
Nooksack River natural origin juvenile Chinook outmigrants