Grenier, star of the show "Entourage," recently joined with NGO Oceana in raising awareness for the plight of the overfished bluefin by swimming with some of the fish, globalshift.org reported.

Oceana’s Bluefin Tuna Campaign seeks to bring protection to the Mediterranean Sea, the second known spawning ground of bluefin tuna.

The organization has called upon the International Commission for the Conservation of Atlantic Tunas (ICCAT) to authorize immediate fishery closures until the bluefin tuna population recovers, protect spawning bluefin, and reduce fishing capacity and the number of tuna ranching operations in the Mediterranean.