1. Satellite Imagery: Advantages and Disadvantages
Peter Fretwell, British Antarctic Survey
Presentation for the INTER-AMERICAN TROPICAL TUNA COMMISSION October 18th 2016

2. Overview of studying whales by Very High Resolution Satellites
Relatively new, highest resolutions very new
Latest technology only tested on larger whales
Unproven for dolphins
Potential positives and negatives of massive amounts of data
Future use will depend on license agreements with satellite provider

3. Very quick history of the method
Ron Abileah 2005
Ron Abileah us Ikonos satellite imagery as a test for future work spotting whales from space. He used spot imagery:
Panchromatic with a 1.5m resolution
Also experimented with
“decluttering” the sea surface to remove the effects of waves and swell

4. Initial studies using 50cm resolution imagery
QuickBird2, 50cm imagery was used to count southern right whales using over Peninsula Valdes
Semi automated methods were developed to identify potential whales
89 whales were counted in the test area

5. Further work
Unpublished work on Blue whales and southern right whales using QuickBird2 and WorldView2 (50cm)
Found that the local turbidity affected the distribution of the whales. And that the present method of survey did not account for this.

6. Auckland Island Habitat suitability model
Boat survey sightings
Rayment et al. 2015
Satellite survey 2011 (blind count)

7. WorldView3 and WorldView4
31 cm spatial resolution panchromatic, 1.24m colour and NIR
This only became available in spring 2015
8 spectral bands, including water penetration “far-blue” band
Each scene covers ~1000km2
Fast repeat potential (less than 1 day)
Request to delivery in less than 1 week.

8. Recent examples of 30 cm imagery
Large unpublished survey of Humpback whales near Maui
Easy to discriminate boats and other confounding factors from cetaceans

9. Humpbacks in WV3 near Maui

10. Fin whale survey of the Pelagos Sanctuary
Fin whales in the Ligurian Sea are rarely seen close to shore and distribution maps are patchy. Satellite imagery is already beginning to help in our knowledge of fin whale distribution
Black dots show recent recorded fin whale sightings. Red dots show fin whales recorded by satellite

11. Fin whales in the Med

12. Advantages Large areas – 1000 km2 + Potential repeat images
low usage/high availability >50km offshore
Cost – either very high or free depending upon license agreement
Non invasive/no disturbance
Anywhere/anytime
Low set-up cost/bureaucracy
5100 km2 of WV3 data over the Pelagos Marine Sanctuary
supplied free of charge taken within 1 week of requesting

13. Disadvantages Unknowns Big data –needs automated procedures developing
Will it work for large groups of dolphins?
How to convert sightings to population estimates? – presence and relative abundance.
Big data –needs automated procedures developing
Download
processing
counting
quality assessment
species ID unlikely
Need agreements with satellite provider
Instantaneous record has implications.

14. Future plans
We currently have a project looking at the effect of turbidity, sea- state, sun angle and satellite angle on the perception availability bias of seeing different species of whales beneath the surface
We have a separate project on the automated identification of whales seals and seabirds in satellite imagery
We intend to discuss with digital globe about access to offshore imagery