The group – including protesters Kristin Bacon, Kim Dutton and Douglas Leith – took responsibility for obstructing police and drivers in the city.
They avoided a conviction as part of a court order, and must pay $100 each to an animal rescue sanctuary.
Another four activists who previously faced court over the same protest were also handed the same penalty.
“The actions we took are confrontational, but we also need to get some perspective. An inconvenience is nothing compared to the brutality and death so many innocents suffer,” Ms Leigh said.