2022 Summary of Ocean Ecosystem Indicators
Long-term monitoring of ocean conditions and their effect on juvenile Pacific salmon survival off Oregon and Washington.
2022 was a mix of good and bad ocean conditions for juvenile salmon in the Northern California Current. Basin-scale indices suggested the coolest, most productive year, with the strongest May–September negative PDO value in the time series; and almost three consecutive years of equatorial La Niña conditions. However, local physical conditions pointed to poor productivity. These were largely driven by the latest spring transition, and the weakest upwelling at 45°N in the 25-year time series. Poor conditions were also reflected in the warm local temperatures on the shelf during the summer.
Despite the lackluster upwelling, the northern copepod biomass anomalies and copepod species richness showed signs of cool conditions in the spring and early summer. Still, the anomalies of northern copepods turned weakly negative by mid-summer, resulting in average biomass anomalies for the May–September period. There was moderate upwelling early in the season, from January– March. This likely drove the summer copepod community's early transition, resulting in low species richness. The winter ichthyoplankton indices and juvenile Chinook salmon catches were moderate. Juvenile coho salmon catches were above average.
The ocean indicators in 2021 pointed towards greatly improved habitat for juvenile salmon and were a welcomed respite following nearly six years of poor ocean conditions. However, the mixed signals in 2022 suggest that these improvements may have been short-lived.
Pacific Decadal Oscillation and Ocean Niño Index
The PDO turned negative (cool phase) in January 2020 and has remained negative through 2022 with some of the lowest (coldest) values in the 25-year time series occurring in 2021 and 2022.
The Ocean Niño Index (ONI) also signaled cold ocean conditions. The ONI turned negative in May 2020 and has remained negative throughout 2022 with La Niña conditions (values less than or equal to -0.5 °C) for the last 15 consecutive three-month periods (August 2021 to October 2022). The National Weather Service Climate Prediction Center predicted ONI to remain negative throughout the winter and transition to ENSO-neutral conditions in February-April 2023.
Upwelling Index at 45°N
Upwelling was the weakest in strength over the 25-year time series. Moderate, intermittent, upwelling favorable winds occurred early in the season from January to March. However, downwelling favorable winds persisted until the spring transition in early June. This was the latest spring transition in the 25-year time series. It was followed by weak upwelling until the fall transition to winter, downwelling conditions in early October.
Sea Surface Temperatures from NOAA Buoys
Upwelling favorable winds in March 2022 resulted in the transition from positive temperature anomalies that occurred in Nov-Dec 2021 to negative sea surface temperature anomalies that persisted through the spring of 2022. Weakly positive temperature anomalies occurred in June 2022, following weak upwelling conditions. Strongly positive temperature anomalies followed in July through September. Cool and neutral temperature anomalies returned in September, the remainder of fall was punctuated by strong positive anomalies.
Water Temperatures on the Shelf and Slope
Along the Newport Hydrographic Line, the near-bottom water temperature on the continental shelf (50 m) was cooler in early 2022 and weakly positive or neutral throughout summer and fall. Conditions on the continental slope (150 m) were similar to shelf waters, with weakly negative anomalies during the winter of 2021/22 and turning positive in May of 2022.
Similar to recent years, we measured hypoxic oxygen concentrations below 1.4 ml/L on the shelf (50-m depth) during each sampling occurrence from June through August 2022. Although hypoxic conditions occurred in summer during most years since 1999, an increased incidence of hypoxic water has happened since 2017.
Northern copepod biomass has been on an upward trend since 2017, and this looked to be a continuing story in the spring of 2022. Northern biomass was neutral or weakly negative May-Sept resulting in average biomass anomalies (rank 16th). This was most likely due to lackluster upwelling in the summer months. Even with low northern biomass, species richness was the second lowest in the time series. Southern copepods were below average for much of 2022, continuing a decline since the marine heatwave that occurred from 2014 - 2016.
The transition from a warm-water lipid-deplete winter copepod community to a cold-water summer community occurred on March 24, 2022, ranking 6th in the time series. This year marks the earliest transition dates since before 2012. The mixed signals in copepod indicators suggest less than favorable feeding conditions for pelagic fishes off central Oregon in 2022.
Colonial tunicates called pyrosomes were common in our plankton nets from fall 2016 through midsummer 2018. However, they have been absent in large numbers over the past several years. Pyrosomes were still low in numbers during our May NCC Ecosystem survey, mainly offshore.
In the winter (January - March) of 2022, the Index of Coastal Prey Biomass (ICPB; blue bars) was below the long-term mean. The biomass was ranked in 14th place in the 25-year time series, suggesting below prey biomass for out-migrating salmon. The community composition (not shown) of ichthyoplankton in 2022 had a higher proportion of coastal taxa than offshore taxa in any year since 2014. Yet, the community was still in the middle of the ordination plot between warm and cold ocean conditions (not shown). These results suggest close-to-average (community) and below-average (ICPB) prey conditions for piscivorous juvenile salmon that out-migrated in 2022.