Thousands of hunters are expected to flock to northern Victoria, with the official start of the duck hunting season kicking off today. But they can count on seeing plenty of anti-hunting activists.

Victoria’s 12-week duck hunting session officially started today and thousands of ducks have already been shot from the sky.

Veteran activist Laurie Levy turned out to protest the season’s launch and was later arrested after holding onto the kayak of a compliance officer who was trying to reach other protesters who had waded out into the wetlands.

He was issued with a fine for more than $800 for his part in the protest.

Greens MP Sue Pennicuik has also attacked the practice.

"If you haven't been there, it's difficult to understand just how distressing it is when you've got shotguns going off everywhere and birds falling out of the sky," Ms Pennicuik said.

Hunters were allowed to take 10 birds today and five birds a day for the rest of the season, which ends on June 8.

Drought and declining water bird numbers has forced the state government to reduce the permitted number of birds hunters may take.