Native and Invasive Bivalves in the Pacific Northwest: Co-occurrence, Habitat Associations and Potential Competition in the Face of Climate Change Active

Native mussels are in precipitous decline across North America. As part of the Confederated Tribes of the Umatilla Indian Reservation’s (CTUIR) First Foods management framework that places significant value on the cultural importance of traditional food resources, they have been identified as a top conservation priority in the Pacific Northwest. Freshwater mussels are a vital component of river ecosystems, a historic food resource, and were used for adornment, jewelry, tools, and trade. Yet, little is known about the basic biology and ecology of these organisms, including where they are, how many of them remain, and what habitat characteristics (e.g., water temperature, flow, etc.) are important to them. There is a pressing need to fill these basic knowledge gaps.

At the same time, the spread of invasive species has become a world-wide threat to native plants and animals. The Pacific Northwest has been affected by the introduction and establishment of many different invasive species, including the invasive Asian clam. There are also other non-native bivalves, such as quagga and zebra mussels, that are an invasion threat that could result in significant economic and ecological damage. The threat of invasive species is expected to be worsened by the effects of climate change.
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Competition between native mussels and invasive clams has recently been documented in the Eastern US and Europe. Specifically, scientists have suggested competition with invasive Asian clams may be affecting native mussels. In the western US, we know little about the interactions between native mussels and invasive clams. In this project, the CTUIR, Washington State University, and the US Geological Survey will collaboratively address this important issue. We will produce information that will help partners and stakeholders better understand how native mussels and invasive clams interact and how these interactions may be affected by climate change.