An individual-based model of the krill Euphausia pacifica in the California Current
Authored by William J Sydeman, Jeffrey G Dorman, Thomas M Powell, Steven J Bograd
Date Published: 2015
DOI: 10.1016/j.pocean.2015.02.006
Sponsors:
California Sea Grant
Platforms:
No platforms listed
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
Model code not found
Abstract
Euphausia pacifica is an abundant and important prey resource for
numerous predators of the California Current and elsewhere in the North
Pacific. We developed an individual-based model (IBM) for E. pacifica to
study its bioenergetics (growth, stage development, reproduction, and
mortality) under constant/ideal conditions as well as under varying
ocean conditions and food resources. To model E. pacifica under varying
conditions, we coupled the IBM to an oceanographic-ecosystem model over
the period 2000-2008 (9 years). Model results under constant/ideal food
conditions compare favorably with experimental studies conducted under
food unlimited conditions. Under more realistic variable oceanographic
conditions, mean growth rates over the continental shelf were positive
only when individuals migrated diurnally to the depth of maximum
phytoplankton layer during nighttime feeding. Our model only used
phytoplankton as prey and coastal growth rates were lower than expected
(0.01 mm d(-1)), suggesting that a diverse prey base (zooplankton, protists, marine snow) may be required to facilitate growth and survival
of modeled E. pacifica in the coastal environment. This coupled IBM-ROMS
modeling framework and its parameters provides a tool for understanding
the biology and ecology of E. pacifica and could be developed to further
the understanding of climatic effects on this key prey species and
enhance an ecosystem approach to fisheries and wildlife management in
this region. (C) 2015 Elsevier Ltd. All rights reserved.
Tags
Ecosystem model
Diel vertical migration
Antarctic krill
North pacific
Population biology
Hyas-araneus decapoda
Oregon
coast
Larval development
Superba dana
Brood size