The Effects of Temporal Variation in
Upper Ocean Processes on Benthic
Boundary Layer Biology and Material Flux
Paul Snelgrove
Verena Tunnicliffe
Claudio DiBacco
Don Deibel
Anna Metaxas
Benthos
Larvae
Kim Juniper
Grant Ferris
Hyperbenthos
Bioturbation
Microbial processes
Doug
Schillinger
Boundary layer flow
Sediment /material
flux
Phil Archambault
Gaston Desrosiers
Alex Hay
Brian Bornhold
Paul Hill
The Big Questions
Craig Smith – Equatorial Pacific Abyssal Plain
•How does material flux (quality and quantity) through
canyon systems relate to boundary layer flow on daily,
seasonal, and event-driven (e.g. slumping) time scales?
•How does flux of organic material (quality, quantity mean
and variance) through canyon systems influence faunal
response (community structure, spawning, bioturbation) of
benthos, hyperbenthos, larvae, and microbes on daily to
event-driven (e.g. slumping) and extended (e.g. regime
shift) time scales?
•How does upper water column variability influence
deep-sea systems on multiple time scales?
BIOSPHERE
Atmosphere
Atmosphere
Response
Variables
Response
Variables
Biodiversity
• Biodiversity
•
Biogeochemistry
• Biogeochemistry
•
Functional
Ecology
Ecology
• Functional
•
Hydrosphere
Hydrosphere
Lithosphere
Lithosphere
Water
Column
Group
Predictive
Variables
Predictive
Variables
Climatic & Oceanographic Variability
(multiple temporal & spatial scales)
(multiple temporal & spatial scales)
Hyperbenthos
Hyperbenthos
Epibenthos
Epibenthos
Infauna
Infauna
Benthic
Group
Sample Questions
1. How do the HBZ, larvae, benthos and material flux respond to
seasonal and spin-off eddy driven variability in Barkley Canyon, and
do episodic changes in the physical regime strongly influence
material flux and biological response?
2. *Do these topographic features support a specialized HBZ and
benthic fauna, enhanced biomass, larger individuals, differences in
feeding mode and activity, and a source of organisms (e.g. larvae)
for adjacent environments?
3. *Are HBZ and benthic faunal responses to flux events in shallower
areas more rapid than in deeper areas, and are there any structural
differences in the response (e.g. types of species, diversity etc.) and
time lags?
*Note that low level of instrumentation will make this question primarily
surface ship sampling based for biological responses.
Barkley Shelf
RDI ADCP (600 kHz)
Nortek HR Aquadopp (2 MHz)
Kongsberg Rotary SONAR
(675 kHz fanbeam)
Boundary layer
measurements
PanTilt Video
Megafauna,
bioturbation, seabed
features
Plankton Pump
Zooplankton
abundance
Sediment trap
Larval, zooplankton
& particle flux
Barkley Canyon
+RDI ADCP (150 kHz)
+Nortek HR Aquadopp (2 MHz)
+Kongsberg Rotary SONAR
(675 kHz fanbeam)
Boundary layer
measurements
+Sediment Trap
+Plankton Pump
Larval, zooplankton &
particle flux
+PanTilt Video
*Delta T Multibeam SONAR
*Hi-Res Camera system
Megafauna, bioturbation,
seabed
features,colonization
*CTD
**Fluorometer
Hydrographic properties &
particulate characterization
*Microbial package
Microbial metabolism
+Pod 3 West
*Pod 4 East
Barkley Axis
Nortek HR Aquadopp (2 MHz)
Kongsberg Rotary SONAR
(675 kHz fanbeam)
Boundary layer
measurements
Seabed features,
bioturbation
Hydrophone
Slumping, turbidity
currents
PanTilt Video
Megafauna,
bioturbation,
seabed features
Sampling Scheme
ADCP, Aquadopp
Continuous sampling
CTD/Fluorometer/Eh
Hydrophone
675 kHz Rotary
SONAR
Scheduled by DMAS
Delta T SONAR
Low light video
Digital Still
Scheduled by instrument
Sediment trap
Plankton Pump
Event Detection: Triggers
•Change in mean current
ADCP, Aquadopp
CTD/Fluorometer/Eh
Hydrophone
•Change in hydrological
properties
•High than normal
backscatter
•Higher than normal fl
•Slumping detected via
hydrophone
Event Detection: Outcomes
675 kHz Rotary
SONAR
Delta T SONAR
Low light video
Digital Still
Sediment trap
Plankton Pump
•Change duty cycle
•Increase sampling
duration
•Unlikely to change
parameters (e.g. range,
resolution)
•Trigger start of new
sample
•Wait for end of “event”
and start new sample
Event Detection: External Triggers
Currents from
Water Column
•Storm
Meteorological
data (inferred)
•Internal waves
Distant
Hydrophones
•Slumping
•Tsunami
Tsunami
i.e.
need access to other water column &
BPR array data
Data
DMAS processing
(immediate)
Scientific post
processing
(1 year +, requires
•currents
•bs amp.
•Ancillary
•Temperature
•Salinity
•Density
•SSL
•SONAR images
•Video
•Digital Stills
•Eh
(cruise dependent
+6 months)
Profile contours
Rectified images
TS Plots
Movies
•Image analysis
•Bedform analysis
•PUV
post-doc)
Lab analysis
Time series
•Plankton samples
•Sediment samples
Bedform data
Sediment/scatter
concentration
Analysis of
discrete samples
(size distribution,
content etc.)
Maintenance & Calibration
•Require removal of entire pod, including JB
every 6-12 months for inspection:
Bulkhead connectors for delamination
Pressure case for pitting and corrosion
Cables and in line connectors for wear
Bio fouling
•Require recovery of samples every 6-12 months
•Need frame alignment on deployment and
recovery
•May place objects at known distance, use
calibration sheet for cameras
Maintenance & Calibration
Possible return to SBE for
calibration
CTD
Replace expired sensor
Eh
675 kHz Rotary
SONAR
Calibration using ROPOS
Delta T SONAR
Low light video
Digital Still
Samples Recovered
Sediment trap
Plankton Pump
Preliminary publications
•Methodological papers on event detection
•Summary of mean/initial conditions
Ways to foster collaboration and future initiatives
•Get data flowing
•Supply travel expenses to groups to showcase
data, budget for staff to manage/process data?
•Post-docs, students to handle the data