Conservationists have been using unique marks on different animals to track their movement over time and to distinguish one animal from another. Humpback whale flukes are like fingerprints and each whale has a unique color pattern, shape and scar marks, allowing scientists to tell the whales apart.
Now a similar technique is being used to identify and eventually to get an accurate census of the world whale shark population. Whale sharks are not whales. They are the largest fish to swim in the sea. Measuring up to 65 feet long and weighing over 20 tons these gentle fish have 3,000 tiny teeth and pose no threat to humans.
We, however, pose a great threat to them. Each year over 73 million sharks are caught and killed mostly for their fins. Shark fin soup is a popular and expensive delicacy in many Asian countries. Although whale shark is not always on the menu many restaurants like to have a whale shark fin up front to indicate that shark fin soup is sold there.
With four-inch thick velvety speckled skin, the whale shark is a popular show piece. But scientists are trying to convince people that these big fish are better left alone and are actually worth more alive than dead. While a fin may fetch over $10,000 from a restaurant, a whale shark over its lifetime could bring in more than $2 million in tourism.
Last summer billionaire Richard Branson swam with 300 whale sharks near Mexico to demonstrate their economic value. The head of Virgin Group says, “They are at the top of the food chain and balance the ocean’s now fragile ecosystem, and the conservation tourism numbers show that they are more useful to coastal communities alive than dead.”
Whale sharks inhabit tropical waters all around the world. Branson says, “Every year, families from around the world travel to the coasts of Central America, Australia, Africa, and Southeast Asia to watch whale sharks feast on summer plankton.”
That business has grown into a $47 million a year ecotourism market. Now at least one scientist wants to take advantage of the popularity of whale sharks and enlist the power of the ecotraveler with a camera.
Tim Davies wants whale shark tourists in the Maldives Islands in the Indian Ocean to keep snapping their pictures. SCUBA divers and snorkelers in the Maldives are already taking underwater pictures of spectacular and docile whale sharks. Now the Imperial College biologist would like to use this photographic resource to help them trace the sharks’ life history, relationships and geographic distribution.
In a paper just released in the journal Wildlife Research he is the first scientist to the first to examine how reliable photographs sourced from the public actually are. And he discovers that when it comes to whale sharks people take some pretty good pics.
An individual whale shark is clearly identified when a photograph captures the distinctive pattern of spots located directly behind the fish’s gills. This unique marking serves as a fingerprint, which can then be scanned with a computer program to tell the animals apart.
The study looked at hundreds of images taken by the public downloaded from public image-sharing websites such as Flickr and YouTube. Individual whale sharks could be successfully identified in 85 per cent of cases, surprisingly close to the 100 per cent identification possible in photographs taken by researchers for comparison.
Davies says, “Globally, this outcome provides strong support for the scientific use of photographs taken by tourists for whale shark monitoring.”
But he has to convince shark researchers that this free data is worth collecting. There is already a simple way for people to post their whale shark pics and vids in a spot that researchers can easily access without having to watch hundreds of hours of homemade YouTube videos.
And this research proves that citizen science projects and crowdsourced initiatives like this work. And that conservation efforts can use Flickr and YouTube as a scientific data repository.
Davies did his master’s thesis on whale sharks in the Maldives where he worked as the resident marine biologist for the Four Seasons Resorts and where the whale shark tourism business is booming and well established. He says, “Hopefully, as more data come in from tourists over the years and from further across the archipelago, we will be able to build up our understanding of the Maldives population and monitor its status closely.”
Despite its enormous size scientists know very little about this big fish. They know whale sharks swim the oceans, covering vast distances, eating only plankton, tiny fish and squid; but questions like how long they live or where they reproduce still remain unanswered. The whale shark population in the Maldives is fairly stable and it is one of a few places where the sharks can be found year-round.
The Maldives Whale Shark Research Programme began in 2006 with the mission “to conduct whale shark research and to foster ‘grass-roots’ conservation initiatives within the Maldives and throughout the Indian Ocean.”
EcoOcean has developed a whale shark identification library where tourists can learn how to properly photograph a whale shark while snorkeling or SCUBA diving. The site is maintained and utilized by marine biologists. Since it began ten years ago there have been over 43,000 photos collected from over 20,000 whale shark sightings in 45 countries.
Cutting-edge software helped Davies rapidly identify whale sharks using pattern recognition and photo management tools. The sharkGrid tool also allows volunteers to donate the processing power of the their computers (think Einstein @ Home or SETI) to help match whale shark spot patterns.
Davies adds, “Our findings support the use of publicly sourced data for use in mark–recapture studies of whale sharks, at least in situations where sharks are resident to the location. This approach will be useful in regions where data collected by tourists are available online, and research funding is limited.”
So all SCUBA divers and snorkelers out in tropical waters can learn how to properly photograph a whale shark and then post their pics in the name of citizen science.