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  • Linking estimates of euphausiid biomass in the California Current Large Marine Ecosystem to ecosystem-based fisheries management


Northwest Fisheries Science Center (NWFSC) Fishery Resource Analysis and Monitoring FRAM - Groundfish Ecology - Fisheries Engineering and Acoustic Technologies


Euphausiid biomass in the CCLME
Linking estimates of euphausiid biomass in the California Current Large Marine Ecosystem to ecosystem-based fisheries management
Euphausiids, or krill, play a significant role in marine food webs and are key prey for many species in the California Current Large Marine Ecosystem (CCLME). Variation in krill abundance can influence growth and recruitment of commercially important fish including Pacific Hake and Pacific Salmon. This project uses a coast-wide time series of krill abundance (2007-2021) that used data from the biennial NWFSC-DFO acoustic trawl survey for Pacific Hake (PPD #4074) to enhance and expand numerous projects at NWFSC. First, the krill classification methods will be operationalized so the time series can be used as a coast-wide index of lower trophic level productivity (PPD #1008). Krill abundance data will be converted to biomass using an inversion model, and data will be made publicly available in the FRAM Data Warehouse to facilitate collaborative studies of top-down, bottom-up, predictive, and climate-related impacts in the CCLME. Models of hake distribution (PPD #3041) will be modified to include spatially-indexed krill biomass to determine if information on prey data improves model performance. Krill biomass will also be incorporated into a multispecies model to inform the Pacific Hake Management Strategy Evaluation (MSE) (PPD #4076). Finally, growth potential models for Hake will be developed using krill biomass and compared to newly processed Hake diet samples (PPD #4053).

Research Themes

Ecosystem approach to improve management of marine resources
The California Current Large Marine Ecosystem, Puget Sound and the Columbia River Basin are home to a wide range of freshwater and marine resources that provide a wealth of ecosystem goods and services. Ensuring the resiliency and productivity of the California Current and Pacific Northwest ecosystems requires an integrated understanding of their structure, function, and vulnerability to increased human population growth in coastal communities and competing uses of coastal waterways and oceans. The NWFSC‘s approach to understanding these large ecosystems integrates studies across ecosystems (terrestrial, freshwater, and marine) and scientific disciplines to inform resource managers responsible for conserving marine resources.
Habitats to support sustainable fisheries and recovered populations
Healthy oceans, coastal waters, and riverine habitats provide the foundation for aquatic resources used by a diversity of species and society. Protecting marine, estuarine and freshwater ecosystems that support these species relies on science to link habitat condition/processes and the biological effects of restoration actions. The NWFSC provides the habitat science behind many management actions taken by NOAA Fisheries and other natural resource agencies to protect and recover aquatic ecosystems and living marine resources. The NWFSC also maintains a longstanding focus on toxic chemical contaminants, as a foundation for regional and national research on pollution threats to fisheries and protected resources.

Research Foci

Assess ecosystem status and trends
Tracking the status of ecosystems across time and space is data intensive as it necessitates evaluating a broad range of trophic levels and environmental conditions from pre-European times to the present. Because ecosystems vary across space and time, the NWFSC must maintain a research focus on the design and implementation of monitoring programs that are capable of capturing this variability. Key research elements are the development and application of novel survey designs, the development of information rich metrics and indicators, and the development of novel spatiotemporal decision support models to facilitate the use of monitoring data in science based decision making. Long-term monitoring program design should be integrated with the development of ecosystem models and indicators to ensure that critical data are collected to support these efforts. An important management goal is the ability to quickly detect important changes in the state of ecosystems (e.g., presence of an invasive species) such that preventative actions can be taken as soon as possible; thus, key management questions and uncertainties should be identified as the structure of monitoring program design to facilitate the decision-making process. It is imperative that the NWFSC’s monitoring science strengths be applied to the design of ecosystem monitoring programs for species (e.g., salmon, rockfish) and ecosystems so that such programs are strategically designed to maximize useable information and minimize cost and effort.
Characterize ecological interactions (e.g. predation, competition, parasitism, disease, etc.) within and among species
Predator-prey interactions, inter- and intra-specific competition, and parasites and pathogens influence the survival, growth, and reproductive success of anadromous and marine fishes, marine mammals and other marine organisms. Moreover, anthropogenic stressors, such as pollution and fishing, can influence these interactions. Because of the complex nature of these interactions, addressing questions about ecological interactions will require novel field and laboratory studies and analyses. This includes ecosystem models, use of innovative technologies (e.g., otolith microchemistry and stable isotopes), integration of sample collection efforts with those of the Ocean Observing System entities on the west coast, and quantifying interactions among environmental stressors, species behavior and ecosystem processes.
Characterize relationships between habitat and ecosystem processes, climate variation, and the viability of organisms
Developing effective conservation and restoration strategies for species or populations requires a clear understanding of how ecosystem processes and climate change will influence the viability of organisms in the future. Key research needs include (1) evaluating the vulnerability of organisms and ecosystems to climate change and human impacts (e.g., fishing, pollution, land use), and (2) devising adaptation strategies that will help achieve conservation goals despite climate change and increasing human pressures. Understanding how climate change or trends in human impacts might influence organisms is based on an understanding of linkages between ecosystem processes, habitat conditions, and abundance, survival or demographics of organisms. This necessitates modeling influences of ecosystem processes on habitats and species, or developing models to examine influences of human pressures on population or ecosystem dynamics. With this foundation, vulnerability assessments can focus on understanding how interactions between climate change and human impacts influence vulnerability of species or populations. Adaptation strategies require knowledge of current conservation needs, predictions of how those needs might change as a result of climate change or future human impacts, and assessments of the robustness of alternative conservation strategies or techniques to climate trends.
Provide scientific support for the implementation of ecosystem-based management
Fisheries scientists and managers recognize the potential for ecosystem-based management to improve sustain the delivery of ecosystem goods and services, including sustainable fisheries resources. An Integrated Ecosystem Assessment (IEA) is one approach that examines all available information on relevant physical, chemical, ecological and human processes in relation to specified ecosystem management objectives. IEAs provide an efficient, transparent means of summarizing the status of ecosystem components, screening and prioritizing potential risks, and evaluating alternative management strategies against a backdrop of environmental variability. To perform IEAs of major ecosystems will require development of project components, including new and existing data, to develop a suite of indicators that characterize the ecosystem. Careful assessment of ecosystem indicators will provide a powerful means for assessing management efficacy and a basis for adapting and improving management practices. A major focus will be to produce the initial IEA of the California Current LME and then provide annual updates.


Ecosystem-based Management
survey methodology
small crustaceans of the order Euphausiacea
marine ecosystems
ecological relationships in marine ecosystems


Spatiotemporal variability of euphausiids in the California Current Ecosystem: insights from a recently developed time series


Family Euphausiidae
Species Anoplopoma fimbria
Species Merluccius productus
North Pacific hake, Pacific hake, Pacific hake, whiting


Andrew Shelton
Internal Collaborator
Dezhang Chu
Internal Collaborator
Elizabeth Phillips
Project Group Lead
Julia Clemons
Internal Collaborator
Mary Hunsicker
Internal Collaborator
Nick Tolimieri
Internal Collaborator
Rebecca Thomas
Internal Collaborator
Steve de Blois
Internal Collaborator