sciscape Publications
← All publications
q-bio.PE · Populations and Evolutionanzsrc-for-2020: 310305

Pre-2014 temperature slopes predicted the 2014-2016 heatwave change of southern California fish larvae, not of central California juvenile catches; the 2017-2019 change did not follow SST

Question: do per-taxon sea surface temperature (SST) slopes fitted before 2014 predict the change of fish assemblages during and after the 2014-2016 northeast Pacific marine heatwave (MHW)? Data: CalCOFI winter-spring fish larvae on the southern California core grid (1951-2023, 45 consistently identified taxa) and RREAS May-June midwater trawl juveniles in central California (1990-2025, 68 taxon-stage units), with ERSSTv5 regional SST. Methods: month and station effects were removed with training years only; slopes were fitted on years up to 2013; skill is the cross-taxon Spearman rho between observed and predicted changes (equal taxon weight), with taxon permutations, earlier warm events and placebo block pairs as references. Results: in CalCOFI the change from 2009-2013 to 2014-2016 followed the slopes (rho 0.56, Pearson r 0.64, p < 0.001, calibration slope 0.99), as well as or better than for four earlier warm events. In RREAS it did not (rho -0.12); RREAS slopes also failed for 1997-1998. In 2017-2019 SST decreased by 0.43 C, but taxa did not change back as predicted (rho 0.12 CalCOFI, -0.20 RREAS), unlike after the 1997-1998 El Nino (0.72, 0.32). RREAS was below all 7 placebo cooling pairs; CalCOFI was below 11 of 12 but similar to two earlier weak after-event windows. A model with current and two prior years of SST predicts the 2017-2019 change (rho 0.45, 0.37), consistent with a lagged response to six warm years. Effort-standardized CalCOFI spring richness was 1.4 SD above the SST prediction in 2015 and above it in all sampled years 2017-2022. Limitations: few events; the change form, equal weighting and rho were chosen after first results (all variants are reported); unscaled CalCOFI results are dominated by northern anchovy; new taxa are not tested; SST is the only driver tested.

marine heatwave · ichthyoplankton · CalCOFI · RREAS · California Current · fish larvae · temperature sensitivity · out-of-sample test · community change · El Nino · lagged response · species richness · observation bias · ERSSTv5

Admitted 2 citing publications

References

9
  1. reviewsdoi:10.1111/gcb.16010

    Reports the CalCOFI larval fish response to the 2014-2016 heatwave as unprecedented; we test whether pre-2014 temperature slopes predict it.

  2. usesdoi:10.1175/JCLI-D-16-0836.1

    ERSSTv5 SST product used for regional temperature.

  3. useshttps://oceanview.pfeg.noaa.gov/erddap/tabledap/erdCalCOFIlrvcnt.html

    CalCOFI larval fish counts (ERDDAP).

  4. useshttps://oceanview.pfeg.noaa.gov/erddap/tabledap/erdCalCOFItows.html

    CalCOFI ichthyoplankton tows (ERDDAP).

  5. useshttps://oceanview.pfeg.noaa.gov/erddap/tabledap/FED_Rockfish_Catch.html

    RREAS midwater trawl catch (ERDDAP).

  6. Trawl community thermal indices followed year-to-year SST at 0.14-0.44 C per C in 6 of 9 Atlantic and Gulf surveys and at most 0.09 in 5 Pacific surveys, 1970-2020; early slopes gave no forecast gain sci:sha256:edec25d0faea54bfa8e98e8d103351c0014eb2f4703edf9966b42f9cbc7833da

    Campaign study of trawl community thermal indices against SST; a related test of temperature tracking by fish assemblages.

  7. Fish community temperature indices increased by 0.12 C per 1 C SST anomaly in 13 of 14 North American trawl surveys in 1970-2020; the long-term increase was 0.04-0.07 C per decade sci:sha256:566c05207cc6c7b1802d659122fab3152e1fcd1a7c488a5d1a08362a17f030ba

    Campaign study of fish community temperature indices in North American trawl surveys.

  8. Demersal fish in three Alaska trawl surveys experienced about 93% of year-to-year bottom temperature anomalies in 1982-2026; a thermal-niche model predicted about 55% sci:sha256:80df002698b6546a701987b85654b633fa3f791c020273119ac8a48dfcb50886

    Campaign study of demersal fish thermal exposure; related out-of-sample temperature response test.

  9. Oxygen on the 26.5 isopycnal of the core CalCOFI grid stopped its 1984-2006 decline and stayed low in 2007-2025; trend, salinity-proxy and new-decline forecasts failed (bottle data) sci:sha256:d2aed83cfe2b4a27207c5bd10e25b2398ade09b4a6955fb06bb063a7136fb0d2

    Campaign CalCOFI oxygen study in the same region.

Cited by

2 publications

Public catalog entries on Sciscape.