Using the FLOWBEC seabed frame to understand underwater interactions - - PowerPoint PPT Presentation

▶
using the flowbec seabed frame to understand underwater
SMART_READER_LITE
LIVE PREVIEW

Using the FLOWBEC seabed frame to understand underwater interactions - - PowerPoint PPT Presentation

Feb 22, 2024 156 likes •301 views

Using the FLOWBEC seabed frame to understand underwater interactions between diving seabirds, prey, hydrodynamics and MREDs Benjamin Williamson, James Waggitt, Eric Armstrong, Paul Bell, Philippe Blondel, Shaun Fraser, Chris Hall, Beth Scott

slide-1
SLIDE 1

Using the FLOWBEC seabed frame to understand underwater interactions between diving seabirds, prey, hydrodynamics and MREDs

Benjamin Williamson, James Waggitt, Eric Armstrong, Paul Bell, Philippe Blondel, Shaun Fraser, Chris Hall, Beth Scott

b.williamson@abdn.ac.uk EIMR 2014 - 463 NE/J004308/1, NE/J004200/1, NE/J004332/1

slide-2
SLIDE 2

FLOWBEC upward facing sonar platform

  • Entire water column (plankton, fish, seabirds, marine mammals)
  • Captures movement, behaviour and interactions with MREDs
  • Self-contained, portable between sites
  • Continuously samples spring/neap 2-week period
  • Complemented by concurrent:
  • hydrodynamic model data
  • above water radar and bird observations
  • Field proven: 5 × 2-week deployments at EMEC, Orkney, UK
slide-3
SLIDE 3

Simrad EK60 echosounder (38, 120, 200 kHz)

  • bird and fish abundance, school behaviour
  • multi-frequency target identification
  • morphology of turbulence, plankton

Imagenex multibeam sonar (260 kHz)

  • interactions of fish, diving seabirds, marine

mammals with MREDs

  • target tracking, avoidance behaviour

FLOWBEC upward facing sonar platform

Seabed Surface EK60 Multibeam

120° Swath

Axis of tidal flow 20-50m

ADV

  • current, temperature, depth

Fluorometer

  • chlorophyll (phytoplankton)
slide-4
SLIDE 4

Turbine structure and seabed Target tracked with multibeam EK60 10-50m (20m shown)

Multibeam for target tracking

History (seconds) t=-7s t=0 (now) Turbine structure and seabed Target tracked with multibeam EK60 10-50m (20m shown) Fish shoal Guillemots / razorbills Sea surface Targets moving with tide Time (9 minutes shown at Wave Energy Site)

Multibeam for target tracking EK60 for multifrequency ID

Acoustic classification ground truthed by shore observations

History (seconds) t=-7s t=0 (now) Turbine structure and seabed Target tracked with multibeam EK60 10-50m (20m shown) Fish shoal Guillemots / razorbills Sea surface Targets moving with tide Time (9 minutes shown at Wave Energy Site)

Multibeam for target tracking EK60 for multifrequency ID

History (seconds) t=-7s t=0 (now)

FLOWBEC upward facing sonar platform

slide-5
SLIDE 5

Multibeam tracking of diving guillemots/razorbills feeding beneath a fish shoal at a wave energy site FLOWBEC first analyses

slide-6
SLIDE 6

Fish shoal Fish shoal

38 kHz 120 kHz 200 kHz

FLOWBEC target tracking

Relative Backscatter Frequency (kHz) 38 120 200

= School of Mackerel Korneliussen (2010)

  • Target detection using the multibeam
  • Target tracking using the multibeam
  • Multifrequency analysis using the EK60

and EK60

Fish shoal

Green = Turbine structure, Dashed = Expected blade radius

slide-7
SLIDE 7

Target vertical distribution next to Atlantis turbine structure

32 Frequency of targets 800 Green = Turbine structure Dashed = Expected blade radius Tracked Target height (m) Tracked Target height (m) 21 Frequency of targets 15

All tracked targets (mammals, birds, fish schools, individual fish) next to Atlantis turbine structure = 3909 tracks over 2 week period Vertical overlap with turbine height = 227 tracks over 2 week period Total = 3909 Total = 227

slide-8
SLIDE 8

Target Classification

Large School Single Target Small School Diving Bird

slide-9
SLIDE 9

Target height (m) 40 Target Intensity 700 500 600 100 200 Target Vertical Distribution Green = Turbine structure Dashed = Expected blade radius

Vertical distribution (collision risk) of target classes

Large School Small School Diving Bird

Target height (m) 40 Target Intensity 700 500 600 100 200 Target Vertical Distribution Green = Turbine structure Dashed = Expected blade radius

slide-10
SLIDE 10

FLOWBEC upward facing sonar platform

Benefits:

  • High range (≈50m) and good detection
  • Visibility / illumination independent
  • Small data volumes (raw ≈ 6GB/day)
  • Low power (self-contained)
  • Realtime processing feasible

Limitations:

  • Limited detail for species identification
  • Observation of final (<1m) interaction

– collision Y/N? – effect of collision?

  • Any behavioural response to acoustics?

Potential solution: multi-instrument integration…

slide-11
SLIDE 11

Multi-instrument integration

Passive acoustic: localisation (~1km)

  • r tag receiver

MBES: behaviour / interactions EK60: abundance / ID Camera: ID / fine-scale behaviour Archival tags integrated in post-processing

Intelligent triggering of instruments across multiple scales

  • Combines large-scale with fine-detail
  • Reduces data processing / archival
  • Cycle passive / active acoustics
  • Trigger camera for ID / detail
slide-12
SLIDE 12

Investigating the ecological effects of installing and

  • perating MREDs

– Determine collision risk probabilities – Define vertical habitat use and any changes in habitat use pre & post installation for a range of species – Increase overall environmental understanding of mobile animal use of high energy sites – Inform marine spatial planning, device design, licensing and operation – Guide scaling-up to arrays and new site selection – Increase predictive power to eventually reduce monitoring

FLOWBEC Summary

slide-13
SLIDE 13

Using the FLOWBEC seabed frame to understand underwater interactions between diving seabirds, prey, hydrodynamics and MREDs

b.williamson@abdn.ac.uk EIMR 2014 - 463 NE/J004308/1, NE/J004200/1, NE/J004332/1