17 Krill

Description Krill are among the most important prey in the CCE. The krill Euphausia pacifica is sampled year-round along the Trinidad Head Line off northern California (see Fig. 1 in the Introduction of this document). Mean adult length and total biomass of E. pacifica sampled off the Trinidad Head Line indicate productivity at the base of the food web, krill condition, and energy content for predators (Robertson and Bjorkstedt 2020; Fisher et al. 2020).

Trinidad Head krill data are provided by E. Bjorkstedt, NMFS/SWFSC SWFSC, Cal Poly, Humboldt and R. Robertson, Cooperative Institute for Marine Ecosystems and Climate (CIMEC) at Cal Poly, Humboldt.

Krill are also detected acoustically during the Joint U.S.-Canada Pacific Hake Ecosystem and Acoustic Trawl (PHEAT) Survey, conducted between June-September from Point Conception, California to Dixon Entrance, British Columbia. The coastwide nautical-area-backscattering coefficient (NASC) represents relative krill abundance observed between 50-300 m water depth (Phillips et al. 2022).

Krill biomass estimates derived from the Joint U.S.-Canada Pacific Hake Ecosystem and Acoustic Trawl (PHEAT) survey hydroacoustic data are provided by E. Phillips, NMFS/NWFSC.

Euphausia pacifica (krill) adult mean biomass

Component Category: Ecological Integrity
Time Range: 2007 - 2024
CCIEA Data Contact: eric.bjorkstedt@noaa.gov
Institution: NOAA SWFSC; Cal Poly Humboldt
Source Data: Krill (Euphausia pacifica) data were provided by Dr. Eric Bjorkstedt (eric.bjorkstedt@noaa.gov), NMFS/SWFSC and Cal Poly Humboldt, and R. Robertson (roxanne.robertson@noaa.gov), Cooperative Institute for Marine, Earth, and Atmospheric Systems (CIMEAS) at Cal Poly Humboldt.
Additional Calculations: Carbon biomass of krill is calculated from body length measurements following length to weight conversions in Fisher et al., 2020.

Euphausia pacifica (krill) length anomaly

Component Category: Ecological Integrity
Time Range: 2007 - 2024
CCIEA Data Contact: eric.bjorkstedt@noaa.gov
Institution: NOAA SWFSC; Cal Poly Humboldt
Source Data: Krill (Euphausia pacifica) data were provided by Dr. Eric Bjorkstedt (eric.bjorkstedt@noaa.gov), NMFS/SWFSC and Cal Poly Humboldt, and R. Robertson (roxanne.robertson@noaa.gov), Cooperative Institute for Marine, Earth, and Atmospheric Systems (CIMEAS) at Cal Poly Humboldt.
Additional Calculations: Carbon biomass of krill is calculated from body length measurements following length to weight conversions in Fisher et al., 2020.

Euphausia pacifica (krill) mean length

Component Category: Ecological Integrity
Time Range: 2007 - 2024
CCIEA Data Contact: eric.bjorkstedt@noaa.gov
Institution: NOAA SWFSC; Cal Poly Humboldt
Source Data: Krill (Euphausia pacifica) data were provided by Dr. Eric Bjorkstedt (eric.bjorkstedt@noaa.gov), NMFS/SWFSC and Cal Poly Humboldt, and R. Robertson (roxanne.robertson@noaa.gov), Cooperative Institute for Marine, Earth, and Atmospheric Systems (CIMEAS) at Cal Poly Humboldt.
Additional Calculations: Krill body length was measured from the back of the eye to the base of the telson.

Euphausia pacifica (krill) total biomass anomaly

Component Category: Ecological Integrity
Time Range: 2007 - 2024
CCIEA Data Contact: eric.bjorkstedt@noaa.gov
Institution: NOAA SWFSC; Cal Poly Humboldt
Source Data: Krill (Euphausia pacifica) data were provided by Dr. Eric Bjorkstedt (eric.bjorkstedt@noaa.gov), NMFS/SWFSC and Cal Poly Humboldt, and R. Robertson (roxanne.robertson@noaa.gov), Cooperative Institute for Marine, Earth, and Atmospheric Systems (CIMEAS) at Cal Poly Humboldt.
Additional Calculations: Carbon biomass of krill is calculated from body length measurements following length to weight conversions in Fisher et al., 2020.

Euphausia pacifica (krill) total mean biomass

Component Category: Ecological Integrity
Time Range: 2007 - 2024
CCIEA Data Contact: eric.bjorkstedt@noaa.gov
Institution: NOAA SWFSC; Cal Poly Humboldt
Source Data: Krill (Euphausia pacifica) data were provided by Dr. Eric Bjorkstedt (eric.bjorkstedt@noaa.gov), NMFS/SWFSC and Cal Poly Humboldt, and R. Robertson (roxanne.robertson@noaa.gov), Cooperative Institute for Marine, Earth, and Atmospheric Systems (CIMEAS) at Cal Poly Humboldt.
Additional Calculations: Krill body length was measured from the back of the eye to the base of the telson.

Indicator Download

ERDDAP™ link:

https://oceanview.pfeg.noaa.gov/erddap/tabledap/cciea_EI_KRILLEN.html

References

Fisher, Jennifer L., Jennifer Menkel, Louise Copeman, C. Tracy Shaw, Leah R. Feinberg, and William T. Peterson. 2020. “Comparison of condition metrics and lipid content between Euphausia pacifica and Thysanoessa spinifera in the northern California Current, USA.” Progress in Oceanography 188: 102417. https://doi.org/https://doi.org/10.1016/j.pocean.2020.102417.

Phillips, Elizabeth M, Dezhang Chu, Stéphane Gauthier, Sandra L Parker-Stetter, Andrew O Shelton, and Rebecca E Thomas. 2022. “Spatiotemporal variability of euphausiids in the California Current Ecosystem: insights from a recently developed time series.” ICES Journal of Marine Science 79 (4): 1312–26.

Robertson, Roxanne R, and Eric P Bjorkstedt. 2020. “Climate-driven variability in Euphausia pacifica size distributions off northern California.” Progress in Oceanography 188: 102412.