CCS Projections for northern anchovy

For this study, we constrained only the partial responses for SST and distance from shore, and set the base-learners to be concave. Environmental covariates were sourced from a high-resolution Regional Ocean Modeling System (ROMS) developed at the University of California - Santa Cruz (Veneziani et al. 2009; Neveu et al. 2016), and the Copernicus-Globcolour level 4 interpolated surface chlorophyll product (doi.org/10.48670/moi-00281).

The environmental variables were extracted from a historical reanalysis (1980-2010) and a near real-time product (2011-2019) of the CCS ROMS implementation, across a domain of 30°-48°N, inshore of 134°W at 0.1° horizontal resolution. To force the projections, daily output from the three downscaled ocean projections for the CCS were used. These downscaled projections are based on an implementation of the same 0.1° ROMS domain described above, with bias-corrected forcing obtained from three earth system models (ESMs) for the period from 1980 to 2100 under the RCP8.5 climate scenario (Pozo Buil et al., 2021).

Downscaled ESMs were selected to span the range of plausible futures for the CCS, and belong to the phase 5 of the coupled model intercomparison project (CMIP5) archive: the geophysical fluid dynamics laboratory (GFDL) ESM2M, Institut Pierre Simon Laplace (IPSL) CM5A-MR and the Hadley Center HadGEM2-ES (HAD). These outputs are free to use, but we strongly recommend contacting Barbara Muhling (bmuhling@ucsc.edu) before working with them, to ensure complete understanding of the details and caveats.

Funding for this work was provided by NOAA Office of Sustainable Fisheries, and the NOAA Climate and Fisheries Adaptation program. References Citores, L., Ibaibarriaga, L., Lee, D. J., Brewer, M. J., Santos, M., & Chust, G. (2020). Modelling species presence-absence in the ecological niche theory framework using shape-constrained generalized additive models.

Ecological Modelling, 418, 108926. Hothorn, T., Buehlmann, P., Kneib, T., Schmid, M., Hofner, B. (2021). mboost: Model-Based Boosting, R package version 2.9-5, CRAN.R-project.org/package=mboost. Neveu, E., Moore, A.M., Edwards, C.A., Fiechter, J., Drake, P., Crawford, W.J., Jacox, M.G. et al. (2016).

An historical analysis of the California Current circulation using ROMS 4D-Var: System configuration and diagnostics. Ocean Model. 99:133-151 Muhling, B., Brodie, S., Snodgrass, O., Tommasi, D., Dewar, H., Childers, J., Jacox, M. Edwards, C. A., Xu, Y. & Snyder, S. (2019). Dynamic habitat use of albacore and their primary prey species in the California Current System.

CalCOFI Reports 60: 1-15. Pozo Buil, M., Jacox, M.G., Fiechter, J., Alexander, M.A., Bograd, S.J., Curchitser, E.N. et al. (2021). A dynamically downscaled ensemble of future projections for the California current system.

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