Citizen science has combined with NASA ingenuity to reveal more secrets about one of the most awe-inspiring creatures in our oceans – whale sharks.
A 22 year-long international project involving 36 researchers globally, including University of Queensland alumni Samantha Reynolds, Dr Simon Pierce and Dr Chris Rohner, has amassed tourist photographs of almost 30,000 encounters to reveal where the enigmatic endangered fish congregate around the world.
An international research team modified an algorithm developed by NASA to recognise star patterns, applying it to the distinctive spots on the sides of whale sharks, allowing the scientists to identify and track individuals.
This online photo database, called Wildbook for Whale Sharks, has identified 6,000 individuals across 54 countries giving the scientists a rich data set to analyse and better understand the species.
The study led by Dr Brad Norman, founder of not-for-profit whale shark conservation group ECOCEAN, has helped researchers identify 20 whale shark aggregation sites, an increase from 13 identified before the project began.
These hotspots include the Ningaloo Reef in Western Australia, the Atlantic coast of Mexico, Mozambique and the Philippines.
Observations of the whale shark population in these areas, and rarer sightings in others, suggests that illegal fishing and lack of conservation can impact the whale shark gatherings.
The project has also revealed:
- That spot patterns on whale sharks are unique and long lasting, and provide a method of individual identification through photographs.
- There is a strong male bias at the majority of sites, showing an overall 66 per cent male population globally.
- Few individual whale sharks move between countries, mostly aggregating around the same hotspots from year to year.
Dr Norman said the information provided by citizen scientists through their photographs was vital for prioritising conservation areas for the species.
Co-author Samantha Reynolds said: “With a broader analysis of environmental variables in the popular sites we will be in a much better position to understand the long-term impacts of climate change on the movements of whale sharks.”
The paper is published in BioScience (DOI: 10.1093/biosci/bix127).
