High-resolution satellite images may be a useful tool for counting whale populations for conservation purposes, according to a study published in PLOS ONE on February 12, 2014 by Peter Fretwell from British Antarctic Survey, UK, and colleagues.
In the study, the authors selected one of the largest southern right whale populations, breeding off the Argentinian coast. The population was selected, due to its large size and tendency to bask near the surface in large aggregations around sheltered coastal waters during breeding season. Scientists used this population to test the potential of using very high resolution satellite imagery to detect and count baleen whales. The satellite imagery was from the highest accuracy satellite, WorldView2, covered 40 square miles, and could penetrate further into the water column than images from other satellites. The authors used four different automatic detection methods and compared the results to those of manual whale detection.
Scientists identified 55 probable whales and 23 other features that could be whales on or just below the surface. In addition, the authors observed 13 objects only detected under certain wavelengths of light. Automatic detection of whale-like objects was also most accurate at specific wavelengths. The authors conclude that these methods are more efficient than traditional methods of assessing populations of marine mammals, and may be used to calculate population abundance. This is one of the first successful studies using satellite imagery to count whales, a method that could be applied to future surveys of other whale species, and other marine mammal populations.
Dr. Fretwell added, "Whales populations have always been difficult to assess, traditional means of counting them are localized, expensive and lack accuracy. The ability to count whales automatically, over large areas in a cost effective way will be of great benefit to conservation efforts for this and potentially other whale species."
Citation: Fretwell PT, Staniland IJ, Forcada J (2014) Whales from Space: Counting Southern Right Whales by Satellite. PLoS ONE 9(2): e88655. doi:10.1371/ journal.pone.0088655
Financial Disclosure: The authors have no support or funding to report.
Competing Interest Statement: The authors have declared that no competing interests exist.
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