MEXICO CITY (AP) — Mexico's environmental department says the plan to capture and enclose the few remaining vaquita porpoises won't begin until autumn because waters in the Gulf of California will be calmer then.

The population of the reclusive porpoises has dropped to about 30, in part because they get caught in nets set for the totoaba fish. Chinese traders pay thousands of dollars for dried totoaba swim bladders.

The department said Tuesday the Mexican government will spend up to $3 million on the capture program in the gulf, also known as the Sea of Cortez.

Experts acknowledge the catch-and-enclose plan is risky because the few remaining females could die during capture.

The department said calmer autumn waters will make it easier to locate the last examples of the vaquita, the world's smallest porpoise.