Handout image released by the Mexican Presidency's press office showing Mexican President Enrique Pena Nieto (L) and US actor Leonardo Di Caprio (R) shaking hands in front of Mexican tycoon Carlos Slim during a meeting about the danger of extinction of the vaquita porpoise (Phocoena sinus) in Mexico City on June 7, 2017. Pic/AFP

The Mexican government, tycoon Carlos Slim and U.S. actor Leonardo DiCaprio on Wednesday unveiled a joint plan to protect a tiny porpoise in the Gulf of California that has become a potent symbol of critically endangered animal species.