The Influence of Diel Vertical Migration on Krill Recruitment to Monterey Bay
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Transcript of The Influence of Diel Vertical Migration on Krill Recruitment to Monterey Bay
The Influence of Diel Vertical Migration on Krill Recruitment to Monterey Bay
Sarah CarrSummer Internship Project
Monterey Bay Aquarium Research InstituteMentor: Francisco Chavez and Tim Pennington
Background
• Using coupled biological-physical model• Physical model:
– ROMS circulation model (UCLA) used to generate current velocity fields of Monterey Bay region
• Coupled model:– Krill (E. pacifica) modeled as Lagrangian drifters
with diel vertical migration (DVM)– Idealized scenarios (passive and idealized DVM)
applicable to other organisms
ROMS Setup
• Grid:– 1.6 km resolution near Monterey Bay– 5 km resolution regionally– Variable vertical resolution (20 sigma levels)
• Driver: Coamps/Quickscat blended wind product
• Time: October 1999 - September 2000
• “Offline” Model Runs: ROMS velocity fields recorded 2X daily and averaged
Grids and Sample Model Output
5 km resolution 1.6 km resolution
Experimental Design• Behaviors
– Passive– Set DVM
• Swimming speed = 50, 100, 200, 300 m/hr (0.01 - 0.08 m/s)
• Vertical velocity = Model vertical velocity + Swimming speed
– Ontogenetic changes in DVM capacity of E. pacifica
Experimental Design
• Release locations:– Horizontal
• 10 krill sampling locations in Monterey Bay
– Vertical• Passive- Surface,
50, 100, 200, 300 m
• All DVM- Surface
Experimental Design• Release times:
– Daily at midnight
– 3 seasons • Upwelling (March- May)
• Oceanic (August-October)
• Davidson (November-January)
• Duration of tracking:– Idealized Behaviors- 20
days
– Krill- ~ 6 mo.
Average alongshore current velocity at the M1 mooring. Figure from Chavez et al. 2002.
Results: Model Sensitivity
• Starting Location• Starting Time:
– Hour
– Day
– Season
• Starting Depth• Behavior
Note: The following results are for particles started at these locations on six consecutive days in January and July 2000.
Temperature/Velocity Fields at Start of Simulations
Sensitivity to Start Time: Season
Sensitivity to Behavior
Sensitivity to Initial Depth-
July 2000
Suggestions?
• Experimental design:– Behavior
– Release locations (H,V)
– Release time
– Duration of tracking
• Visualization– Trajectories (2D, 3D)
– Particle Density