Imaging plankton to understand Gulf of Mexico ecology and potential interactions with oil
Adam T. Greer
Assistant Research Professor
Deepwater Horizon (April 20, 2010) – 11 lives lost
Below the surface
https://www.whoi.edu/oceanus/feature/where-did-deepwater-horizon-oil-go
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What is plankton?
Holoplankton
Meroplankton
Phytoplankton(O2 production)
Zooplankton Marine Snow
Planktos – “wanderer” or “drifter”
Why do we care about plankton?• Critical link in the food web
• Early life stages of many animals (meroplankton)
• “Canaries in the coal mine”
• Marine snow exports carbon and can entrain other materials (e.g., oil)
CONCORDE – nGOM river-dominated shelf ecosystem
Critical area for:1) Fisheries2) Transport
processes (river plumes, fronts, winds, etc.)
Plankton ecology links these two topics!
Greer et al. 2018 Oceanography 31(3)
Conventional plankton sampling methods
• Bongo nets
• Multiple Opening and Closing nets• Better vertical resolution
• Minimum vertical scale is at least 10 m, horizontal scales of 100’s of meters
• Biases in organism detection
New Optical Systems• High resolution (cm to m scale)
• (Semi or fully) automated data processing
• Fewer biases among different organisms (sample gelatinous plankton well)
• Sample volumes & imaging techniques
• Most are towed or profiled
Images from Benfield et al. 2007
Video Plankton Recorder (Davis et al. 2004)
Underwater Video Profiler (Gorsky et al. 2001)
Large Area Plankton Imaging System (Madin et al. 2006)
• Line-scan camera
• Motor actuated wings
• 16-17 images per second (12 cm * 12 cm * 50 cm)
• 2 TB of image data every 3.5 hours
In Situ Ichthyoplankton Imaging System
Sample plankton and water properties to describe…
• Physical structure• Temp, salinity, light, oxygen
• Fronts, eddies, internal waves
• Currents
• Biological structure• Patterns produced by
feeding and predation
• Competition
• Social interactions
Both relevant to ocean ecology and oil/pollutant exposure rates
Chiaverano et al. in prep
Plankton thin layers
• Common in many coastal areas – not well-studied in the GOM
• Ecological significance: concentrated feeding zones (community composition matters)
• Affect predicted oil exposure rates
GOM thin layer during summer (July 24, 2016)
4.3 cm
Zooplankton around the thin layer
Take Home Message(s)
• Imaging data revealing key relationships between planktonic organism abundance and oceanographic properties.
• This information is needed to determine which organisms will be exposed to oil in the event of a spill.
The ISIIS data are complex.
Behavioral interactions Size and orientation information
Thank [email protected]
Marine snow • Abundance and distribution • Shapes (indicate sinking)