The European Outdoor Conservation Association hand out money for conservation projects based on public voting. Their current list of projects is themed on reducing plastic pollution and includes a cave conservation project in the lava tubes of Mauritius. This would entail a nationwide cave clean up, monitoring of bats and swiftlets, and education and interpretation.
If you want to give the project a better chance of winning the funding, you can vote for it here: http://www.outdoorconservation.eu/project-info.cfm?pageid=19
(it's in the 'Nature' category)