Climate Change Effects on Freshwater Aquatic and Riparian Habitats in Washington State


Published: May 28, 2010

Pages: 42


This paper is intended as a reference document "science summary" for the Ecosystems, Species, and Habitats Topic Advisory Group (TAG), which is one of four topic groups working with state agencies to prepare a statewide Integrated Climate Change Response Strategy. The climate change response strategy was initiated by the state legislature (SB 5560) to help the state adapt to climate change.

The purpose of this paper is to provide TAG members with information on potential climate change effects on fish, wildlife, habitats, and ecosystems in freshwater environments so as to inform the assessment of priorities and the development of recommendations about adaptation responses. The paper is intended to summarize and organize relevant literature regarding observed changes, future projections and implications for biological communities.

This document draws from synthesis reports, government publications, non-profit publications, and peer-reviewed studies. These include the two primary reference documents for the Integrated

Climate Change Response Strategy, which are:

  • The Washington Climate Change Impacts Assessment: Evaluating Washington's Future in a Changing Climate (WACCIA) (CIG, 2009); and
  • Leading the Way: Preparing for the Impacts of Climate Change in Washington.Recommendations of the Preparation and Adaptation Working Groups (PAWG, 2008).

This document is for discussion purposes only and is not intended to be published or cited. In many cases, this document uses language taken directly from the cited sources. Readers should refer to and cite the primary sources of information.

Please note that we accepted information as it was presented in synthesis reports. Readers may wish to return to the primary sources utilized in those synthesis reports for more information. In cases where we accepted the interpretation of primary information as it was stated in a secondary source, we have provided the following note in the footnote: "Information as cited in [secondary source]."

As with most summary or synthesis efforts, this document reports the central findings from published literature and typically does not address the inherent complexity and uncertainty that may be present. This is especially true of future projections, which are often based on multimodel ensembles that do not perfectly capture the complexity of Washington's unique climate systems and geographic variability. These projections are valuable primarily to identify a directional trend and a sense of magnitude. As an example of the inherent uncertainty of future projections, the WACCIA notes that multi-model ensembles of global climate projections may under-represent the local severity of climate change.1

This paper is a joint production of National Wildlife Federation and Washington Department of Fish & Wildlife. Dan Siemann and Erin Morgan led the effort from NWF and Ken Warheit led the effort from WDFW. This draft benefitted from the review and input of Doug Inkley (NWF) and many WDFW scientists, including John Kerwin, Casey Baldwin, Dan Ayres, Mara Zimmerman, Marc Hayes, Tim Quinn, John Pierce, Hal Beecher and David Price.

We must emphasize that this discussion draft is neither comprehensive nor complete. In this complex and rapidly evolving field, we do not expect that we have identified all of the most up-to-date data or presented the complexity of climate projections. In addition, there are many gaps in knowledge, especially regarding climate change effects on specific habitats or locations. Still, we hope that this provides a starting point for discussion, and that readers will augment

1 Salath, et al. (2009) Regional climate model projections for the State of Washington. In: WACCIA