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The Effects of Temporal Variation in Upper Ocean Processes on Benthic Boundary Layer Biology and Material Flux

Paul Snelgrove Anna Metaxas Verena Tunnicliffe Claudio DiBacco Don Deibel Kim Juniper

Grant Ferris

Benthos Larvae Hyperbenthos Bioturbation Microbial processes Boundary layer flow Sediment /material flux

Phil Archambault Gaston Desrosiers Alex Hay Brian Bornhold Paul Hill

The Big Questions

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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?

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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?

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How does upper water column variability influence deep-sea systems on multiple time scales?

Craig Smith – Equatorial Pacific Abyssal Plain

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Water Column Group Climatic & Oceanographic Variability (multiple temporal & spatial scales) 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 Canyon *Nortek Aquadopp (2 MHz) +Kongsberg Mesotech Rotary Sonar (2.25 MHz fanbeam) Boundary layer measurements +Sediment Traps +Plankton Pump +PanTilt Video Larval, zooplankton & particle flux Megafauna, bioturbation, seabed features *CTD *Fluorometer Boundary layer water mass and particulate characterization *Hi-Res Camera system *Microbial package Bioturbation, seabed features colonization Microbial metabolism

*Pod 1 +Pod 2

Plankton Pump •High volume pump •Concentration mechanism •Multiple samples •Scheduled and event triggered

Barkley Canyon

MODEL Collecting area (sqm) Shape Baffle Number of samples Volume of sampling bottles* Sampling interval Operating depth MATERIALS Trap body Carousel Sampling bottles* Electronics/motor pressure case Mooring bar Power supply DIMENSIONS (mm) Height Diameter WEIGHT (kg) In air In water PPS 4/3 PPS 3/3 0,05 0,125 Cylindro-conical on request 12 or 24 250 ml 1 hour - 60 days 3500 m (6000m on request) PPS 5/2 1 Conical (36

) Honeycomb cells 24 250 ml 1 hour - 60 days 6000 m Barkley Shelf Barkley Canyon

Sediment Trap

(Technicap)

Glass reinforced polyester (GRP) on an alimentary gel-coat PETP (very hard thermoplastic) Polypropylene Polypropylene external GRP PETP Polypropylene Aluminium alloy (AG 5086) Titanium (T 40) Stainless steel (316) Titanium (TA6V) AA or/and AAA alkaline batteries

•Multiple samples •Scheduled and event triggered

1200 250 27 11 1900 400 39 16 2300 1330 95 32

Aquadopp 2 Mz

Barkley Shelf Barkley Canyon Barkley Axis

Aquadopp 600 kHz

Barkley Shelf

Vector

(Nortek)