A study by the Georgia Aquarium and Mote Marine Laboratory, shows anywhere from 500 to 1,500 whale sharks feeding on plankton between Mexico's Isla Holbox and Isla Contoy during the summer months.  

They have been working with Mexico's National Commission on Protected Natural Areas since 2003 to tag the whale sharks and record their mating, eating and movement habits. One whale shark travelled 550 miles in 31 days, and another dove 4,514 feet into the ocean.

The Georgia Aquarium is the only facility outside of Asia to display whale sharks, two of which, Ralph and Norton - died unexpectedly this year.

Ralph died of peritonitis, an infection in his abdomen. Norton was euthanized in June after he settled to the bottom of the tank with signs of weakness.

Norton displayed the same symptoms as Ralph: swimming erratically and loss of appetite. However, aquarium officials are still not sure what caused his illness though researchers suspect a chemical used in 2006 to clean the sharks' aquarium.

The Chinese freshwater dolphin is now likely to be extinct

A team of scientists in China has failed to find any Yangtze river dolphins, also known as Baijis, during a six-week survey of the mammals' habitat.

The World Conservation Union's Red List of Threaten Species currently classifies the creature as critically endangered.

Dr. Sam Turvey of the Zoological Society of London, one of the paper's co-authors, described the findings as a "shocking tragedy".

The Yangtze river dolphin (Lipotes vexillifer) was the only remaining member of the Lipotidae, an ancient mammal family that is thought to have separated from other marine mammals over 20 million years ago.

The white, freshwater dolphin had a long, narrow beak, low dorsal fin, lived in groups of three or four and ate fish.