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

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

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

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

Further work Unpublished work on Blue whales and southern right whales using QuickBird2 and WorldView2 (50cm) Found that the local turbidity affected the distribution of the whales.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.

Auckland Island Habitat suitability model Boat survey sightings 2010-2012 Rayment et al. 2015 Satellite survey 2011 (blind count)

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.

Recent examples of 30 cm imagery Large unpublished survey of Humpback whales near Maui Easy to discriminate boats and other confounding factors from cetaceans

Humpbacks in WV3 near Maui

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

Fin whales in the Med

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

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.

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