WATCH: Angry vegans confront fishermen and 'save a fish life'

Angry animal activists have saved "a fish life" after two fishermen left it flapping on the pavement, sparking a heated argument.

The father and son caught a Tilapia at Cresent Lake Park in St Petersberg, Florida, and left it alive on the ground while throwing their fishing lines back in.

Vegan activists then filmed the moment they approached the anglers to ask if they were "going to let this fish die like this".

A heated discussion ensued with the protesters asking how the father and son would feel if the fish were a dog with a hook through its cheek being thrown into the water.

"We don't eat dogs," one of the men responded.

The activist then explained to the fisherman why he chooses not to eat animal products.

"We don't eat any animals because all animals have the same ability to feel love and pain just like we do, would you guys agree with that?" he asks.

"Do you guys think that this is okay to let this fish die right here? What if this was a human child? [Animals] have the same ability and the same emotions as a human child."

The men both disagree and the protester then picks up the fish from the pavement and throws it back into the lake.

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The shocked fishermen tell him he was "stealing" and accuse him of "harassment."

"Call the police! I just saved a fish life, how about that?" the activist yells.

The fishermen did call local police after the fish was thrown back and the St. Petersburg Police Department said the protesters were already leaving when they arrived, NBC reported.

“The primary concern for the officer was to restore the peace and the officer didn’t witness any disorderly conduct or criminal activity," a statement said.

"The officer documented the call as well as the names, addresses, and auto tag numbers of the principal protesters.

"Whether one agrees with the message or not, any group has a right to free speech in a public park."