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  • Population structure and viability of SRKW and other top marine predators


Northwest Fisheries Science Center (NWFSC) Conservation Biology CB - Ecosystem Science - Marine Mammal Ecology; CB - Mathematical Biology and Systems Monitoring


Marine mammal population structure and viability
Population structure and viability of SRKW and other top marine predators
The Southern Resident killer whale (SRKW) population is threatened by a number of identified risk factors including prey availability, contaminants, vessel noise and disturbance, and small population size. However, the population may also be subject to internal factors that limit population growth. Continued assessment of the discreteness of this population through morphological and genetic characteristics is important for maintaining ESA status and understanding intrinsic factors affecting the recovery of the population. In addition, an annual census provides important information that allows demographic analyses of this population to be conducted in order to assess population viability. The components of this project represent a significant level of investment of base funds over many years, and these data and analyses provide the foundation of information against which all research and management actions are measured that are attempting to address key risk factors of the SRKW population as protected under the ESA and MMPA.

Data Sets

no data found

Research Themes

Recovery and rebuilding of marine and coastal species
The Pacific Northwest is home to several iconic endangered species, including Pacific salmon and killer whales, and several rockfish species. Mandates such as the Endangered Species Act, MagnusonStevens Act, and the Marine Mammal Protection Act, grant NOAA Fisheries the authority to manage the recovery of depleted species and stocks. The NWFSC contributes to species recovery through research, monitoring and analysis, providing NOAA managers and regional stakeholders the tools and information they need to craft effective regulations and develop sustainable plans for recovery.

Research Foci

Develop methods to use physiological, biological and behavioral information to predict population-level processes
Understanding the biological processes occurring within organisms is a powerful way of understanding how environmental changes affect those organisms. Genetics, developmental, physiological and behavioral studies all provide important information for effective species recovery and rebuilding. Integrating this information into models is vital to predict how populations will respond to natural or human perturbations, and to assess the constraints to stock rebuilding efforts. For example, data on thermal tolerance and physiological responses to temperature can be used to explore changes caused by shifts in climate on reproductive behavior and productivity, viability, movement, habitat selection, and population dynamics. Similarly, data on contaminants that impact physiological processes (immune system, growth, development, reproduction, and general health) are critical in determining how these compounds affect population dynamics. Data on biological responses of organisms to ocean acidification are useful for understanding how acidification may affect individual development and survival. The NWFSC collects such information for several species that are of concern, targets of fisheries or otherwise important for overall ecosystem function. NWFSC scientists will continue to expand current efforts and develop methods to incorporate physiological, biological and behavioral data into population models in order to predict population-level processes from these individual level data.


population trends
annual index of abundance
southern resident killer whale
DPS that this study is focused on


None associated


Species Orcinus orca
grampus, killer whale, killer-trasher, orca


Brad Hanson
Principal Investigator
Eric Ward
Internal Collaborator
Kim Parsons
Internal Collaborator
Krista Nichols
Martin (Marty) Kardos
Internal Collaborator
Mike Ford
Internal Collaborator