BECI logo
North Pacific Ocean Knowledge Network (DEMO)
Understanding Ocean Change Across the North Pacific

Pacific Cod

Gadus macrocephalus

Recovering

Population Recovery Following Historic Climate-Driven Collapse

Alaska Pacific cod stocks are recovering following severe declines during the 2014–2016 and 2019 marine heatwaves. The Gulf of Alaska stock experienced a 71% biomass decline (2015–2019) driven by increased metabolic demand, reduced prey availability, and reproductive timing shifts. The fishery was closed in 2020 and a federal disaster declared in 2022. The 2023 NOAA stock assessment determined the Gulf of Alaska population is not overfished and not subject to overfishing, showing signs of recovery. Rebuilding efforts continue with reduced catch limits and enhanced monitoring across all three Alaskan stocks.

Stock Status (2023 Assessment)
NOT
Overfished Status
2023 NOAA determination
NOT
Overfishing
2023 NOAA status
+56%
GOA Biomass Change
2019 → 2024
52,034
GOA Biomass 2024
MT (NOAA)
Variable
Recruitment
Climate-influenced
NPFMC
Management Body
Alaska Fisheries
📝
While the population experienced a climate-driven collapse (not primarily due to fishing pressure), the 2023 NOAA assessment officially determined the stock is not overfished and not subject to overfishing by federal definitions. The collapse was driven by marine heatwave impacts rather than harvest pressure.
Alaska Pacific Cod Stock Recovery (2019–2024)

Biomass trends across the three Alaskan stocks

201920202021202220232024
Gulf of AlaskaBering SeaAleutian Islands
Habitat & Distribution
🗺️
Life History & Distribution Map

Pacific cod spawning areas, juvenile nursery habitats, adult feeding areas, and seasonal depth migrations in the Gulf of Alaska and Bering Sea.

Climate-Driven Impacts & Stock Responses
Collapse Period
2015–2019
Recovery Period
2020–present
Hatch Timing Shift
2–3 weeks earlier
Persistent phenology change
Thermal Habitat
Compressed
During heatwaves
GOA Distribution
No shift detected
Habitat compression
Population Response
Declined in place
Climate-driven mortality
💡
Key Finding: Gulf of Alaska Pacific cod experienced habitat compression and population collapse during marine heatwaves without detectable range shifts. In contrast, eastern Bering Sea cod successfully shifted ~1,000 km northward into the northern Bering Sea (2020–2018), demonstrating different responses to warming between stocks. GOA cod face thermal constraints in their existing habitat that mechanisms preventing movement remain unclear.
Data Confidence: HIGH · Based on annual NOAA bottom trawl surveys, otolith analysis
Data Sources: NOAA Alaska Fisheries Science Center 2023 stock assessments (Gulf of Alaska, Bering Sea, Aleutian Islands); North Pacific Fishery Management Council (NPFMC); Alaska groundfish bottom trawl surveys (2019–2024). Biomass Trends: AFSC survey (2019–2024). Last Update: October 2025 ·BIC Project: Basin-scale climate events and coastal impacts | North Pacific Ocean Knowledge Network
Life History
Maximum Age
~25 years
Max Length
120 cm
Age at Maturity
3-4 years
Trophic Level
4.2 (predator)
Habitat
Demersal, 10-250m
Management
Management BodyUS NPFMC
Stocks Managed3 (BS, AI, GOA)
2024 GOA Biomass52,034 MT
2024 BS Biomass223,048 MT
2024 AI Biomass25,223 MT
Fishery StatusActive (managed)
Assessment CycleBiennial
NOT Overfished (2023)NOT Overfishing (2023)Recovery OngoingClimate-Driven Decline
Climate Vulnerability
Overall VulnerabilityHIGH
Temperature SensitivityVery High
Marine Heatwave ImpactCritical
Adaptive CapacityLow (GOA)
Dispersal LimitationUnknown mechanism

Primary threats: increased water temperature, reduced prey availability and quality, thermal habitat compression, phenological mismatches, and continued marine heatwave risk.

Ecosystem Role
Primary PreyPollock, capelin, crab
Key PredatorsSeals, sea lions, orcas
Cultural ImportanceHigh (Indigenous)
Economic Value Rank#2 GOA groundfish

Welcome to the North Pacific Ocean Knowledge Network Dashboard

This interactive platform connects and synthesizes information about changing ocean conditions, key species, and management approaches across the North Pacific. The North Pacific Ocean Knowledge Network is being developed through the Basin-scale Events and Coastal Impacts (BECI) project to transform fragmented research and data into accessible, actionable insights that support climate-informed fisheries management and conservation decisions across jurisdictions.

Demo Platform Notice

This demonstration showcases the platform's structure and functionality. Some content is illustrative to demonstrate proof-of-concept capabilities. Information presented here should not be used for management decisions or policy development. The full operational platform will contain only verified, peer-reviewed, and validated information from authoritative sources.