NEPTUNE Canada: Project Details

Project Details

Disturbance in deep-sea ecosystems

The role of disturbance in deep-sea benthic ecosystems

Principal investigator(s)

Paul Snelgrove & Anna Metaxas

Co-investigators

Phillippe Archambault, Brian Bornhold, Grant Ferris, Alex Hay, Kim Juniper, Verena Tunnicliffe

Discussion & Collaboration

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Abstract

Deep-sea ecosystems are the largest and among the most species-rich habitats on Earth, but are also among the least sampled. Studies to date suggest that environmental disturbances in the deep sea contribute significantly to habitat heterogeneity and recruitment variability on and above the sea floor. However, these studies have limited by a dependence on ship-based sampling. NEPTUNE observing system will provide us with unprecedented quality and volumes to information on the deep ocean. Using monitoring and responsive sampling with NEPTUNE, we can address for the first time how deep-sea faunal response is influenced by input of organic and inorganic material on temporal scales from days to decades. In particular, we will investigate the relative impacts on the deep-sea benthos of material flux from the overlying water column and from the nearby continental shelf and via a submarine canyon. These data will significantly advance our understanding of deep-sea ecosystems.

Study Sites/Locations

Sites at Barkley Shelf, Barkley Canyon & Axis comprise the main core of our research program and encompass a transect from shelf to abyssal depths. We hope to include targeted sampling at opportunistic intervals to better resolve the spatial component of the biology present in the region.

Site 1 - Barkley Canyon Axis: The ecological and biological response to episodic events will be easy to monitor with both optical (camera) and acoustical (sonar) imaging equipment and an acoustic current profiler.
Site 2 - Barkley Shelf: Co-operation with the water column group is paramount at this site for making physical measurements from bottom to surface.
Site 3 – Barkley Mid-Canyon East: This combined package of turbidity and boundary layer instruments complements the high resolution imaging devices at site 4.
Site 4 – Barley Mid-Canyon West: High-resolution digital still camera and a fast frame rate SONAR allow comparison of imaging techniques in regions where light pollution might affect biological measurements.

Equipment Summary

Acoustic Doppler Profiler: Emits coded acoustic pulses and measures the Doppler shift from the signal returned by scatterers in the water column. The shift in acoustic frequency is converted to velocity, and the average velocity of all the scatterers in the acoustic beam is recorded. Apart from measuring currents, measurements of the acoustic backscatter amplitude can give qualitative insight into concentrations of scatterers.
Rotary SONAR: This instrument emits an acoustic pulse in a fan beam and measures the acoustic backscatter amplitude as a function of time. The acoustic transducer can rotate through 360 degrees providing an acoustic image of the sea-bed or any object (fish or scientific frame) which might be in the acoustic path.
Multi-Beam SONAR: This device emits an acoustic pulse via multiple beams and returns 20 frames per second in a 120 degree by 20 degree swath. The frame rate approaches the frame rate for real-time video and provides an alternative means to image in environments where light pollution will affect the local biology.
Conductivity, Temperature, Depth/Pressure (CTD): Measures temperature and conductivity of the water and the water-pressure at the sensor. Conductivity is related to the salinity through an empirical relationship, while pressure, force per unit area, is directly related to the weight of the water (and air) column above. Salinity and temperature are both hydrological properties and affect the growth of local biology.
Microbial package
Fluorometer: Measures the fluorescence in the water. The primary food source in the food chain of the ocean are phytoplankton. These organisms emit light, or fluoresce. By measuring the fluorescence biologist get a direct reading on the amount of primary production in the area.
Hydrophone: An underwater microphone which measures sound waves in the frequency range from (5 Hz – 50 kHz). These measurements are used to study geo-physical process (e.g. slumping), biology (e.g. whales) and meteorological phenomenon (e.g. wind speed, rain).
Video cameras: Mounted on pan/tilt swivels these black and white cameras are able to point in nearly any direction. Video recorded from these cameras will shed light on the range of organisms living in this benthic environment.
High resolution still camera: Mounted on pan/tilt swivel this high definition colour video and digital still device has 10x optical zoom. The images recorded by this device will return spectacular images of deep-sea organisms.

How this project will foster collaboration

Our team consists of scientists from multiple disciplines and institutions, and we believe it includes most of the deep-sea benthic expertise in Canada. Although most investigators are primarily biologists, marine geologists and physicists are key members of our project. Moreover, most of the biologists are trained as interdisciplinary oceanographers with expertise in areas such as boundary layer flow and biological- physical coupling. We include investigators from 6 academic institutions (Memorial, Dalhousie, UQ Rimouski, UQAM, UBC andUVic) and the federal government (Fisheries and Oceans Canada). Many of us have collaborated on successful NSERC and/or CFI proposals and/or cruises in the past (e.g. Deibel & Snelgrove; Metaxas & Snelgrove; Metaxas, Tunnicliffe & Juniper; Metaxas, Deibel & Desrosiers, Deibel & Archambault; Deibel & Juniper; Metaxas, Hay & Hill; Juniper & Ferris). Many collaborations are long- standing (5-20 yrs), and extremely productive. Formal partnerships in marine sciences have already been established among academic institutions (e.g. through NEPTUNE). The proposed research will expand and strengthen these collaborations.

Most of the PIs collaborate with other Canadian scientists both within and outside their own institutions, and many maintain strong links and active collaboration with scientists in the United States with assistance from US funding programs (e.g. NOAA Ocean Exploration & NURP, ONR, NSF). Early success at NEPTUNE will attract these scientists to our program, since many share common interests and have been active in US NEPTUNE. Given these links, we believe we are an a unique position to integrate with US and other international scientists into NEPTUNE.

Our project is strongly integrated with the Water Column Processes Group. We have maintained active communication and will share some data sets, and write collaborative manuscripts. The cameras and SONAR which central to our work, will provide spectacular images to enhance NEPTUNE's outreach potential.