5 Sharks, Rays Needing Urgent Protection: Photos 
 
 Pedro Afonso of the University of the Azores and his colleagues wrote that the “occurrence of the whale shark in the wider Azores region increased drastically in 2008. "Large marine animals such as the whale shark can change their oceanic distributions depending on regional conditions," Afonso said. They usually inhabit tropical and warm-temperate seas, preferring temperatures from 78.8 degrees Fahrenheit to 86 degrees. In Portugal, the authors note that “whale sharks — local name ‘pintados’ — are known by Azorean fishermen to sometimes occur during the summer and associate with tuna, and have been used for a long time as an aid to locating and fishing the tuna schools.” 
 
 But the sharks have been coming even more often than that, to the point that "whale shark watching" tourism has become a growing business in the region. [Image Gallery: Mysterious Lives of Whale Sharks] 
 
 To better understand why these gargantuan fish appear more often around the Azores, the scientists analyzed data on whale shark sightings gathered over 16 years, from 1998 to 2013, by observers on tuna fishing boats. The researchers used computer models to investigate the patterns of whale shark sightings over time and space, in relation to factors such as food, sea surface temperatures and seafloor features. Usually the Azores fall into the colder side of the sharks’ preferred range, but water temperature rises at this location are proving to be a draw for sharks. "Is it only the food around the seamounts, or something else — maybe the presence of other whale sharks to mate with?"
– Those hoping to avoid the world's biggest sharks would do well to stay away from Portugal's Azore Islands. That's where whale sharks—the biggest fish in the sea—are making a new home, likely due to climate change, a study finds. The creatures have a very specific set of temperatures they can tolerate, ranging from 78.8 degrees to 86 degrees Fahrenheit, Discovery notes. The Azores are currently fulfilling the needs of the animals, which, LiveScience notes, can be up to 41.5 feet long and weigh a whopping 47,000 pounds. The temperatures around the Azores, off western Europe, appear to be linked to higher amounts of a favorite whale shark food: chlorophyll-a. Researchers in the area came to their shark population conclusions by assessing 16 years of data from tuna fishermen who've spotted the animals. Indeed, so many sharks have headed there that the region, previously in the northernmost part of the sharks' territory, is experiencing a boom in tourists' "whale shark watching." These tourists, it seems, needn't fear: Whale sharks are by no means ferocious, LiveScience points out. Great whites are a little scarier.