Slide 2 Figures courtesy of Matt Oliver 10 years of data Slide 3
Slide 4 Slide 5 Sea floor http://detlaphiltdic.blogspot.com Slide 6
Krill Biomass Estimate of weight (grams) of krill through water
column at a single point Averaged over survey grid for each day =
mean daily krill biomass Slide 7 Krill Aggregations For each
aggregation we calculate: Mean depth, dimensions (L, H), nearest
neighbor distance Volumetric abundance and biomass (ind. m -3 and g
m -3 ) Aggregation-specific integrated biomass (g m -2 ) Biomass
encounter rate (kg m -1 ) Slide 8 Error bars are 2 standard errors
Slide 9 Slide 10 Slide 11 Slide 12 Central place foraging Minimize
foraging time Maximize energy intake Krill aggregation structure
impacts foraging efficiency Depth, size, densities and distance to
next aggregation are important Slide 13 Diurnal Tide Shallow Large
Closer together More dense Highest biomass encounter rate
Semi-Diurnal Tide Deep Small Further apart More dense Low biomass
encounter rate Shallow Large Further apart Less dense Low biomass
encounter rate Palmer Deep Slide 14 Summaryand more questions
Nearshore Antarctic krill distribution patterns are highly variable
Tide plays a role - but how? Aggregation structure seems to be
affected by tide and has an impact on penguin foraging, but to what
degree? What types of aggregations are penguins going after? Slide
15 Pilot Field Season Palmer 2013-2014 Two acoustic grids within
the Palmer Station boating limits: East Grid (~13 nm, 23 km) West
Grid (~12 nm, 22 km) Traveling at ~3-4 knots = 6-8 hours Sampling
as frequently as possible Predator observations from the water
species identification, behavior Slide 16 Acoustic Grids
