State of the California Current Ecosystem in 2021: Winter is coming?

In late 2020, models predicted that a strong La Niña would take place for the first time since 2013, and we assessed whether physical and biological indicators in 2021 were similar to past La Niñas in the California Current Ecosystem (CCE). The Pacific Decadal Oscillation and Oceanic Niño Index indeed remained negative throughout 2021; the North Pacific Gyre Oscillation Index, however, remained strongly negative. The seventh largest marine heatwave on record was unexpectedly present from April to the end of 2021; however, similar to past La Niñas, this mass of warm water mostly remained seaward of the continental shelf. As expected from past La Niñas, upwelling and chlorophyll were mostly high and sea surface temperature was low throughout the CCE; however, values were close to average south of Point Conception. Similar to past La Niñas, abundances of lipid-rich, northern copepods off Oregon increased. In northern California, unlike past La Niñas, the body size of North Pacific krill (Euphausia pacifica) was close to average. Predictably, overall krill abundance was above average in far northern California but, unexpectedly, below average south of Cape Mendocino. Off Oregon, similar to past La Niñas, larval abundances of three of six coastal species rose, while five of six southern/offshore taxa decreased in 2021. Off California, as expected based on 2020, Northern Anchovy (Engraulis mordax) were very abundant, while Pacific Sardine (Sardinops sagax) were low. Similar to past La Niñas, market squid (Doryteuthis opalescens) and young of the year (YOY) Pacific Hake (Merluccius pacificus), YOY sanddabs (Citharichthys spp.), and YOY rockfishes (Sebastes spp.) increased. Southern mesopelagic (e.g., Panama lightfish Vinciguerria lucetia, Mexican lampfish Triphoturus mexicanus) larvae decreased as expected but were still well above average, while northern mesopelagic (e.g., northern lampfish Stenobrachius leucopsarus) larvae increased but were still below average. In line with predictions, most monitored bird species had above-average reproduction in Oregon and California. California sea lion (Zalophus californianus) pup count, growth, and weight were high given the abundant Anchovy forage. The CCE entered an enduring La Niña in 2021, and assessing the responses of various ecosystem components helped articulate aspects of the system that are well understood and those that need further study.

[1]  E. Hazen,et al.  Global seasonal forecasts of marine heatwaves , 2022, Nature.

[2]  B. Semmens,et al.  Fisheries Surveys Are Essential Ocean Observing Programs in a Time of Global Change: A Synthesis of Oceanographic and Ecological Data From U.S. West Coast Fisheries Surveys , 2022, Frontiers in Marine Science.

[3]  M. Hunsicker,et al.  Evidence of Temperature‐Driven Shifts in Market Squid Doryteuthis opalescens Densities and Distribution in the California Current Ecosystem , 2022, Marine and Coastal Fisheries.

[4]  E. Chenoweth,et al.  Rapid Range Expansion of a Marine Ectotherm Reveals the Demographic and Ecological Consequences of Short-Term Variability in Seawater Temperature and Dissolved Oxygen , 2021, The American Naturalist.

[5]  D. Kacev,et al.  Putting the Pacific marine heatwave into perspective: The response of larval fish off southern California to unprecedented warming in 2014–2016 relative to the previous 65 years , 2021, Global change biology.

[6]  R. Brodeur,et al.  Prey Selectivity and Diet Partitioning of Juvenile Salmon in Coastal Waters in Relation to Prey Biomass and Implications for Salmon Early Marine Survival , 2021, Technical Report.

[7]  J. Santora,et al.  Diverse integrated ecosystem approach overcomes pandemic-related fisheries monitoring challenges , 2021, Nature Communications.

[8]  V. Godínez,et al.  Water masses and larval fish habitats in the Pacific tropical-subtropical convergence off Mexico , 2021, Continental Shelf Research.

[9]  Edward D. Weber,et al.  State of the California Current 2019–2020: Back to the Future With Marine Heatwaves? , 2021, Frontiers in Marine Science.

[10]  J. Färber Lorda,et al.  Trophic position and partitioning differences between euphausiid species in the Southern California Current and eastern tropical North Pacific using stable isotope ratios (δ13C and δ15N), elemental composition, and lipid contents , 2021, Marine Biology.

[11]  M. Kavanaugh,et al.  Pelagic Biodiversity, Ecosystem Function, and Services: An Integrated Observing and Modeling Approach , 2021, Oceanography.

[12]  O. Olsson,et al.  COVID-19 lockdown reveals tourists as seabird guardians , 2021, Biological Conservation.

[13]  Roxanne R. Robertson,et al.  Climate-driven variability in Euphausia pacifica size distributions off northern California , 2020 .

[14]  Curry J. Cunningham,et al.  The changing physical and ecological meanings of North Pacific Ocean climate indices , 2020, Proceedings of the National Academy of Sciences.

[15]  A. Maccall,et al.  Sixty-five years of northern anchovy population studies in the southern California Current: a review and suggestion for sensible management , 2020 .

[16]  M. Fewings,et al.  Regional Structure in the Marine Heat Wave of Summer 2015 Off the Western United States , 2019, Front. Mar. Sci..

[17]  Gregory D. Williams,et al.  Indicators of pelagic forage community shifts in the California Current Large Marine Ecosystem, 1998–2016 , 2019, Ecological Indicators.

[18]  A. Moore,et al.  Source water variability as a driver of rockfish recruitment in the California Current Ecosystem: implications for climate change and fisheries management , 2019, Canadian Journal of Fisheries and Aquatic Sciences.

[19]  Russell W. Bradley,et al.  Prey switching and consumption by seabirds in the central California Current upwelling ecosystem: Implications for forage fish management , 2018, Journal of Marine Systems.

[20]  James V. Carretta,et al.  Population growth and status of california sea lions , 2018 .

[21]  W. Peterson,et al.  Phytoplankton Community Structure in 2011–2013 Compared to the Extratropical Warming Event of 2014–2015 , 2018 .

[22]  P. Xiu,et al.  Future changes in coastal upwelling ecosystems with global warming: The case of the California Current System , 2018, Scientific Reports.

[23]  Elizabeth A. Daly,et al.  Phenological and distributional shifts in ichthyoplankton associated with recent warming in the northeast Pacific Ocean , 2018, Global change biology.

[24]  Edward D. Weber,et al.  CORRECTING FOR BIAS IN CALCOFI ICHTHYOPLANKTON ABUNDANCE ESTIMATES ASSOCIATED WITH THE 1977 TRANSITION FROM RING TO BONGO NET SAMPLING , 2018 .

[25]  James D. Scott,et al.  Forcing of Multiyear Extreme Ocean Temperatures that Impacted California Current Living Marine Resources in 2016 , 2018 .

[26]  Edward D. Weber,et al.  STATE OF THE CALIFORNIA CURRENT 2016-17: STILL ANYTHING BUT "NORMAL" IN THE NORTH , 2017 .

[27]  Matthew J. Burke,et al.  Ecological surprise: concept, synthesis, and social dimensions , 2017 .

[28]  M. Fewings.  Large-Scale Structure in Wind Forcing over the California Current System in Summer , 2017 .

[29]  J. Santora,et al.  Impacts of ocean climate variability on biodiversity of pelagic forage species in an upwelling ecosystem , 2017 .

[30]  A. R. Thompson,et al.  Larval abundances of rockfishes that were historically targeted by fishing increased over 16 years in association with a large marine protected area , 2017, Royal Society Open Science.

[31]  R. Asch,et al.  Climate, Anchovy, and Sardine. , 2017, Annual review of marine science.

[32]  A. R. Thompson,et al.  Food limitation of sea lion pups and the decline of forage off central and southern California , 2016, Royal Society Open Science.

[33]  H. Ling.  in the northeast Pacific Ocean , 2016 .

[34]  A. J. Smit,et al.  Under Pressure: Climate Change, Upwelling, and Eastern Boundary Upwelling Ecosystems , 2015, Front. Mar. Sci..

[35]  John C. Field,et al.  Long-term variation in a central California pelagic forage assemblage , 2015 .

[36]  C. Möllmann,et al.  The importance of within-system spatial variation in drivers of marine ecosystem regime shifts , 2015, Philosophical Transactions of the Royal Society B: Biological Sciences.

[37]  Steven J. Bograd,et al.  State of the California Current 2014-15: Impacts of the Warm-Water "Blob" , 2015 .

[38]  J. Peterson,et al.  Applied Fisheries Oceanography: Ecosystem Indicators of Ocean Conditions Inform Fisheries Management in the California Current , 2014 .

[39]  P. Cury,et al.  Resolving Hjort's dilemma how is recruitment related to spawning stock biomass in marins fish ? , 2014 .

[40]  Brian K Wells,et al.  Spatio-temporal dynamics of ocean conditions and forage taxa reveal regional structuring of seabird–prey relationships. , 2014, Ecological applications : a publication of the Ecological Society of America.

[41]  M. Hixon,et al.  Food for thought BOFFFFs: on the importance of conserving old-growth age structure in fishery populations , 2014 .

[42]  S. McClatchie.  Regional Fisheries Oceanography of the California Current System , 2013, Springer Netherlands.

[43]  D. Checkley,et al.  The State of the California Current in 1998-1999: Transition to Cool-Water Conditions , 2013 .

[44]  Edward D. Weber,et al.  State of the California Current 2012–13: No Such Thing as an "Average" Year , 2013 .

[45]  William J. Sydeman,et al.  Mesoscale structure and oceanographic determinants of krill hotspots in the California Current: Implications for trophic transfer and conservation , 2011 .

[46]  R. Brodeur,et al.  The response of fish larvae to decadal changes in environmental forcing factors off the Oregon coast , 2011 .

[47]  R. González-Armas,et al.  Mesopelagic fish larval assemblages during El Niño-southern oscillation (1997-2001) in the southern part of the California Current , 2011 .

[48]  R. Rykaczewski,et al.  Does positioning of the North Pacific Current affect downstream ecosystem productivity? , 2011 .

[49]  A. Maccall,et al.  Bocaccionomics: the effectiveness of pre-recruit indices for assessment and management of bocaccio. , 2010 .

[50]  J. Laake,et al.  UNPRECEDENTED MORTALITY OF CALIFORNIA SEA LION PUPS ASSOCIATED WITH ANOMALOUS OCEANOGRAPHIC CONDITIONS ALONG THE CENTRAL CALIFORNIA COAST IN 2009 , 2010 .

[51]  David M. Checkley,et al.  Patterns and processes in the California Current System , 2009 .

[52]  H. Harvey,et al.  Comparative lipid dynamics of euphausiids from the Antarctic and Northeast Pacific Oceans , 2009 .

[53]  Harold P. Batchelder,et al.  Forecasting Northeastern Pacific Ecosystem Responses to La Niña , 2008 .

[54]  R. Brodeur,et al.  Feeding patterns and predation potential of scyphomedusae in a highly productive upwelling region , 2008 .

[55]  James C. McWilliams,et al.  North Pacific Gyre Oscillation links ocean climate and ecosystem change , 2008 .

[56]  Steven J. Bograd,et al.  Time series of the northeast Pacific , 2007 .

[57]  Suzann G. Speckman,et al.  Prey density and the behavioral flexibility of a marine predator: the common murre (Uria aalge). , 2007, Ecology.

[58]  S. Jiménez-Rosenberg,et al.  Influences of El Niño on assemblages of mesopelagic fish larvae along the Pacific coast of Baja California Sur , 2006, Fisheries oceanography.

[59]  S. Ralston,et al.  INTERANNUAL AND SPATIAL VARIATION IN THE DISTRIBUTION OF YOUNG-OF-THE-YEAR ROCKFISH (SEBASTES SPP.): EXPANDING AND COORDINATING A SURVEY SAMPLING FRAME , 2006 .

[60]  Richard R. Veit,et al.  Ocean warming and seabird communities of the southern California Current System (1987–98): response at multiple temporal scales , 2003 .

[61]  Francisco P. Chavez,et al.  From Anchovies to Sardines and Back: Multidecadal Change in the Pacific Ocean , 2003, Science.

[62]  M. Love,et al.  The Rockfishes of the Northeast Pacific , 2002 .

[63]  W. Sydeman,et al.  Survival, breeding probability and reproductive success in relation to population dynamics of Brandt's Cormorants Phalacrocorax penicillatus , 1999 .

[64]  D. Pauly,et al.  Primary production required to sustain global fisheries , 1995, Nature.