Dataset: Larval sablefish observations, environmental data, and associated analysis code from 1995-2018

Sablefish larval data: We collated data from five long-term ichthyoplankton sampling programs covering the region between the Southern California Bight (35° latitude) to the Alaska Peninsula in the western Gulf of Alaska. From north to south, these surveys were the National Oceanic and Atmospheric Administration (NOAA) Ecosystems and Fisheries Oceanography Coordinated Investigations (EcoFOCI), multiple compiled surveys organized by Department of Fisheries & Oceans Canada (DFO), the NOAA Pre-recruit Survey, Newport Hydrographic Line (NH-Line), and the California Cooperative Oceanic Fisheries Investigations (CalCOFI). Larval data includes samples taken by oblique and paired bongo tows with 236-505 µm mesh from throughout the study area, along with neuston tows from Alaska and southern California. Neuston tows had 505 µm mesh and net openings between 0.13-15 m2. Tows were subset to 1995 to 2018 within the 200 nmi Exclusive Economic Zone within ocean or estuarine waters (salinity ≥ 30 ppt). The northern geographic extent of the area examined was bounded by the latitudinal range of positive tows (59.8°N). We restricted the southern limit to be ≥ 35°N latitude. From north to south, these surveys were the National Oceanic and Atmospheric Administration (NOAA) Ecosystems and Fisheries Oceanography Coordinated Investigations (EcoFOCI), multiple compiled surveys organized by Department of Fisheries & Oceans Canada (DFO), the NOAA Pre-recruit Survey, Newport Hydrographic Line (NH-Line), and the California Cooperative Oceanic Fisheries Investigations (CalCOFI).

Environmental data: Environmental data were extracted from a 10-km Regional Ocean Modeling System (ROMS) configured for the eastern Pacific at a 10-km resolution from 1995-2020 (Pozo Buil et al. in prep). The model was forced with daily atmospheric fields from the ERA5 reanalysis produced by European Centre for Medium-Range Weather Forecasts (Hersbach et al. 2020) and with open-ocean boundary conditions from the 1/12° Global Ocean Reanalysis and Simulation (Lellouche et al. 2021) with a five-day resolution. We extracted sea surface temperature (SST), sea surface height (SSH), sea surface salinity (SSS), and spiciness from ROMS. Spiciness was averaged over the upper 250 m of the water column, corresponding to the maximum depth sampled across the five programs. Empirical catch data collected from field sampling were matched to ROMS data using bilinear interpolation. Bottom depth (i.e., water depth at each sampling location) was extracted for each data point using R package ‘marmap’ (Pante and Simon-Bouhet 2013) which uses bathymetry 15 arc-second data from the 2022 NOAA Earth TOPOgraphy dataset (National Centers for Environmental Information [NCEI] 2022).