Video of a heated confrontation on a Sooke dock is sparking questions about what is and isn't allowed when it comes to crabbing.

The video, which first surfaced on Facebook Monday, shows a man trying to educate two people after they allegedly filled a bucket with undersized crabs.

It has been viewed more than 66,000 times and shared more than 600 times on the popular social media site, with many commenters praising the man trying to teach a couple the rules.

"Do you have a measuring stick?" the man asks the couple. When they say no, he replies, "Well that's your first mistake."

He proceeds to throw crabs from the bucket back into the water, saying they're undersize.

"You're only allowed four crab per person, you're not allowed to keep females, you have a bucket full of undersize crab, you don't know what you're doing, you have no measuring device," he says.

After exchanging some more heated words with the man, the couple eventually packs up and leaves the dock at the end of the six-minute video.

A Department of Fisheries and Oceans spokeswoman asks people to avoid getting into conflict, even in the name of education.

"We don't want people engaging in potential conflicts that could compromise their safety or the safety of the public around them," said DFO officer Mandy Ludlow, adding that the DFO is aware of the video.

Ludlow clarified some of the rules around crabbing for people who aren't aware.

"The most common with recreational crab fishing that I've observed is the retention of undersized crab," she said.

Dungeness crabs must be at least 165 millimetres wide, while red rocks must measure at least 115 mm. Anything smaller means the crabs haven't had a chance to breed.

"So you're affecting the recruitment of the population," said Ludlow.

Crabbers must also flip caught crustaceans over to determine whether they're male or female. Males' abdomens are long and narrow, while females are considerably shorter and wider. Only males are permitted to be taken.

Anyone in violation of the rules can face hefty penalties.

"For the first crab that you're found in possession that's undersize, it's $150, and for every other crab after that it's $150 additionally up to $1,000," said Ludlow. "After $1,000, if you're grossly over, then you would go to a mandatory court appearance."

Anyone planning to pull up a trap must also carry a tidal waters sport-fishing licence, which stipulates a catch limit of just four crabs per day, per person.

More information on crabbing and fishing regulations can be found on the DFO's website.