Natural Population Assessment Group Members

Program Lead: Will Simpson

Group Members:

Marshall Barrows    Tim Blubaugh    Brian Davis

Julie Harris    Nate Queisser    Paul Sankovich

About the Natural Population Assessment Group 

The Natural Population Assessment Group is responsible for the monitoring and evaluation of native fish species in the Pacific Northwest. Group responsibilities include investigating the spatial and temporal distribution of fish populations, their movement and migration patterns, estimating population abundance and trends, and determining how these relate to habitat conditions and anthropogenic changes to habitat. We also monitor invasive fish in an effort to develop strategies that minimize their detrimental effect on native fish and wildlife and their habitat. Our mission is to provide scientific-based contributions to the management and conservation of aquatic species native to the Pacific Northwest. We seek to collaboratively anticipate and resolve knowledge gaps that are essential to assessing the status and trends of USFWS trust species and to investigate scientifically-defensible ways to mitigate any negative effects of anthropogenic change to native species and their habitats. The team works with internal (Ecological Services and Refuges) and external (WDFW ODFW, USGS, Bureau of Reclamation, USFS and the Confederated Tribes of the Umatilla Indian Rerservation) co-managers and listing agencies in a variety of forums to address these uncertainties. Ultimately our goal is to support USFWS managers and our partners by providing them strong scientific information like data, novel tools, analyses, and resulting interpretation for integration into the decision support and adaptive management that is required to develop recovery strategies for USFWS trust species that are ESA-listed or are species of concern. 

Our group is addressing the impact of  climate change climate change
Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.

Learn more about climate change
 on aquatic species by exploring how warming temperature regimes affects (1) mortality and changes in physiology, growth, and movement of adult Pacific Lamprey and (2) behavior and metamorphosis of larval Pacific Lamprey. We also examine the impact of climate change on the distribution of ESA-listed Bull Trout. We are using a variety of tools like electrofishing and eDNA to determine the current distribution of Bull Trout in eastern Oregon.  By comparing this distribution baseline to any changes in their future distribution, scientist can better understand if and how these changes are related to warming temperatures brought about by climate change. Additionally, our office represents the FWS Fisheries and Aquatic Conservation Program by providing technical expertise about the impact of anticipated climate change on Bull Trout status and recovery as part of a review group that works on Species Status Assessment.