Diel vertical migration of Antarctic krill (Euphausia superba) is flexible during advection across the Scotia Sea

We model a summer snapshot of the behavior of Antarctic krill (Euphausia superba) during advection across the Scotia Sea. Individual krill respond to a changing landscape of predation risk and food availability by migrating vertically in the column and choosing an average distance to their nearest n...

Full description

Bibliographic Details
Published in:Journal of Plankton Research
Main Authors: Cresswell, K A, Tarling, Geraint, Thorpe, S E, Burrows, Michael, Wiedenmann, J, Mangel, M
Format: Article in Journal/Newspaper
Language:English
Published: 2009
Subjects:
ELEPHANT-ISLAND
INTERANNUAL VARIABILITY
POPULATION-DYNAMICS
MACARONI PENGUINS
Marine & Freshwater Biology
NATURAL GROWTH-RATES
PENGUINS EUDYPTES-CHRYSOLOPHUS
SEASONAL DISTRIBUTION
Oceanography
DIVING BEHAVIOR
SOUTH SHETLAND ISLANDS
SOCIAL AGGREGATION
Antarctic
Antarctic Peninsula
Elephant Island
Scotia Sea
South Shetland Islands
The Antarctic
Antarc*
Antarctic Krill
Eudyptes chrysolophus
Euphausia superba
Online Access:https://pure.uhi.ac.uk/en/publications/f04c78ec-29c9-487f-9893-ba071f424ab0
https://doi.org/10.1093/plankt/fbp062
Description
Summary:We model a summer snapshot of the behavior of Antarctic krill (Euphausia superba) during advection across the Scotia Sea. Individual krill respond to a changing landscape of predation risk and food availability by migrating vertically in the column and choosing an average distance to their nearest neighbor (swarm density). We determine the optimal behavior of 30, 40 and 50 mm krill using a state-dependent life history model where individuals move along 30-day segments of hypothetical journey tracks in three different regions of the Scotia Sea, with the tracks extracted from a combination of circulation models and surface drifter data. Food availability is based on satellite data for surface Chl and with additional heterotrophic and detritus food components, and mortality is parameterized with respect to distance from shore, daylight and krill swarming-behavior. We predict that proximity to predator colonies has a distinct effect on behavior, particularly on depth choice when food-availability is low. Observations made during an acoustic survey of the region found swarms to be deeper at the Antarctic Peninsula compared with South Georgia, in line with model pedictions. Our pedictions are also consistent with observations that swarm density, changes little on a logarithmic scale across the region. We show that being able to change behavior on short time scales has distinct advantages to krill.

Similar Items