A [study published](http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0065051) in the Public Library of Science (PLOS) ONE journal has quantified the revenue that is accrued from tourism related activities associated with manta rays. In the 23 countries in which manta ray watching operations met the study's criteria, direct revenue to dive operators from manta ray dives and snorkels is estimated at over US$73 million annually and direct economic impact, including associated tourism expenditures, at US$140 million annually. Read more »