TABLE 1.
Description of datasets used to identify changes in availability, abundance, and quality of forage species, as well as coincident changes in lower and upper trophic‐level taxa in the Northern Gulf of Alaska (GOA) during the 2014–2016 Pacific marine heatwave.
| Purpose | Taxa | Region, Index (units) | Years, Source |
|---|---|---|---|
|
Middle trophic level: Forage fish abundance indices PWS |
Forage Fish | GOA summer frequency in seabird diets | 1993–2019, GWA |
| Capelin | GOA summer acoustic‐trawl, pelagic trawl, and bottom trawl survey anomalies (CPUE, kg km−2) | 2000–2019, NOAA AFSC | |
| Herring | PWS spring aerial spawning index (mile‐days milt) | 1980–2019; ADF&G | |
| Middle trophic level: Forage fish quality indices | Capelin | PWS July male spawning age (years), length (total length, mm) | 2013, 2016; GWA |
| Sand lance | GOA summer size proportional CPUE in seabird diets (fish sample−1) | 1993–2019, GWA | |
| Sand lance | PWS July age‐1 total energy (kJ) | 2012–2016, 2018; GWA | |
| Herring | PWS age‐3 annual growth increment anomaly (mm), and weight at age anomaly (g) | 1979–2017; ADF&G | |
| Herring | PWS March, November age‐0 whole fish total energy (kJ) | 2007–2016; HRM | |
| Lower trophic level: Zooplankton abundance indices | Euphausiid | GOA shelf/PWS May, September mean biomass (g m−3) | 2012–2017; GWA |
| Copepod | PWS monthly mean abundance by species group (m−3) | 2012–2017, GWA | |
| Copepod | GOA shelf monthly mean abundance by species group (sample−1) | 2009–2018, GWA | |
| Macrozooplankton | PWS September acoustic macrozooplankton index (nautical area scattering coefficient, m2 nm−2) | 2014, 2017–2019; GWA | |
| Upper trophic level: Marine predator indices | Humpback whale | PWS September encounter rate (individuals effort−1) | 2008–2015, 2017–2019; GWA |
| Humpback whale | PWS September crude index of birth rate (calves individual−1) | 2008–2015, 2017–2019; GWA | |
| Murre | GOA/PWS/Katmai density anomaly (birds km−2) | 2006–2019; GWA |
Abbreviations: ADF&G, Alaska Department of Fish and Game; CPUE, catch per unit effort; GWA, Gulf Watch Alaska long‐term ecosystem monitoring program; HRM, Herring Research and Monitoring Program; NOAA AFSC, National Oceanic and Atmospheric Administration Alaska Fisheries Science Center; PWS, Prince William Sound.