Paul Snelgrove Anna Metaxas

The Effects of Temporal Variation in Upper Ocean Processes on Benthic

Boundary Layer Biology and Material Flux

Paul Snelgrove

Anna Metaxas

Claudio DiBacco

Don Deibel

Alex Hay

Brian Bornhold

Paul Hill

Benthos

Larvae

Hyperbenthos

Bioturbation

Microbial processes

Boundary layer flow

Sediment /material flux

Verena Tunnicliffe

Kim Juniper

Grant Ferris

Phil Archambault

Gaston Desrosiers

Doug Schillinger

•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?

The Big Questions

Craig Smith – Equatorial Pacific Abyssal Plain

Atmosphere

Hydrosphere

Lithosphere

BIO

SP

HE

RE

Response Variables

•Biodiversity

•Biogeochemistry

•Functional Ecology

Predictive Variables

(multiple temporal & spatial scales)

HyperbenthosEpibenthosInfauna

AtmosphereAtmosphere

HydrosphereHydrosphere

LithosphereLithosphere

BIO

SP

HE

RE

Response Variables

• Biodiversity

• Biogeochemistry

• Functional Ecology

Predictive VariablesClimatic & Oceanographic Variability (multiple temporal & spatial scales)

HyperbenthosEpibenthosInfauna

Water Column Group

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.

Boundary layer measurements

Megafauna, bioturbation, seabed features

RDI ADCP (600 kHz)Nortek HR Aquadopp (2 MHz)Kongsberg Rotary SONAR

(675 kHz fanbeam)

PanTilt Video

Plankton Pump Zooplankton abundance

Sediment trap Larval, zooplankton & particle flux

Barkley Shelf

+RDI ADCP (150 kHz) +Nortek HR Aquadopp (2 MHz)+Kongsberg Rotary SONAR

(675 kHz fanbeam)

+Pod 3 West*Pod 4 East

+PanTilt Video*Delta T Multibeam SONAR*Hi-Res Camera system

*CTD **Fluorometer

Boundary layer measurements

+Sediment Trap+Plankton Pump

*Microbial package

Barkley Canyon

Larval, zooplankton & particle flux

Megafauna, bioturbation, seabed features,colonization

Hydrographic properties & particulate characterization

Microbial metabolism

Barkley Axis

Slumping, turbidity currents

Megafauna, bioturbation, seabed features

Kongsberg Rotary SONAR (675 kHz fanbeam)

Nortek HR Aquadopp (2 MHz)

Hydrophone

PanTilt Video

Boundary layer measurements

Seabed features, bioturbation

Sampling Scheme

Continuous sampling

Scheduled by DMAS

Scheduled by instrument

ADCP, Aquadopp

CTD/Fluorometer/Eh

Hydrophone

675 kHz Rotary

SONAR

Delta T SONAR

Low light video

Digital Still

Sediment trap

Plankton Pump

Event Detection: Triggers

ADCP, Aquadopp

CTD/Fluorometer/Eh

Hydrophone

•Change in mean current

•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

Meteorological

data (inferred)

Distant

Hydrophones

Tsunami

i.e. need access to other water column & BPR array data

•Storm

•Internal waves

•Tsunami

•Slumping

Data •currents•bs amp.•Ancillary•Temperature•Salinity•Density•SSL•SONAR images•Video•Digital Stills•Eh

•Image analysis•Bedform analysis•PUV

•Plankton samples•Sediment samples

Lab analysis

(cruise dependent +6 months)

DMAS processing

(immediate)

Time series

Profile contours

Rectified images

TS Plots

Scientific post processing

(1 year +, requires

post-doc)

Movies

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

Calibration using ROPOS

CTD

675 kHz Rotary

SONAR

Delta T SONAR

Low light video

Digital Still

Sediment trap

Plankton Pump

Samples Recovered

Possible return to SBE for calibration

Replace expired sensor Eh

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