Fisheries officials say they are reviewing a video showing crew on a large ship boasting about catching hundreds of Dungeness crabs while visiting Vancouver — and appearing to break numerous fishing regulations in the process.

Video circulating on social media since last week shows the Mandarin-speaking merchant sailors hauling up crab traps dangling off the side of the massive commercial vessel, their catch appearing to include illegal undersized and female crabs.

It's also illegal to pull crab traps at night, as shown in the video, while the possession limit is four per person.

"We don't need to sleep tonight. Overkill. Catching crabs until dawn. Crabs are estimated at 441 pounds," says a subtitle on the video.

After the men are shown pulling up the crabs, the scene cuts to the galley where the crabs are cooked in metal steamers and the men have a feast, washed down with cans of Tsingtao beer.

"It smells so good," says one sailor, while the man next to him adds "my mouth is watering."

Parts of Vancouver's harbour are off-limits to crabbing, and while the men say they have stopped in "Vancouver, Canada," it's not clear exactly where the vessel is anchored.

Fisheries and Oceans Canada (DFO) said it is aware of the video and taking the matter "seriously," while the Port of Vancouver said it wanted to help educate visiting sailors about local rules.

"We are currently reviewing the video for any potential indicators that may warrant further investigation," DFO said in a statement. 

Subtitles on the video say the men made some of the traps themselves, pulling them up every 10 minutes and at one stage catching more than 100 crabs in two hours, with no time for bathroom breaks.

The name of the ship isn't given or shown in the video.

The Port of Vancouver said in a statement that it was concerned about the "alleged behaviour" and would provide DFO with support to properly investigate. 

"We will also look into how we can work with Fisheries and Oceans Canada to help visiting ships and their crews understand their rights and responsibilities while in Canadian waters, such as proactively sharing relevant information regarding fishery licensing and regulations,“ read the statement.

Jason Voong, president of the B.C. Crab Fishermen’s Association, has seen the videos, and said it was bad practice for people to go crabbing without any knowledge or respect for local rules.

"The rules and regulations are there to make sure that crab fishing remains sustainable," said Voong, a second-generation crab fisherman. 

"Anyone around the world is eligible to come to B.C. and catch crabs. You just have to get a sport fishing licence. Even if you're not a Canadian resident, you can still get a crab fishing licence," said Voong.

"Our rules are, you can only get males, no females, because females lay thousands of eggs, and they have a high reproduction rate," he added.

Voong said the minimum size for retaining a Dungeness crab is 16.5 centimetres across the widest part of the shell.

Dungeness crabs in B.C. are well known for their flavourful meat, and they're harvested year-round along the coast. 

Voong said his fondest fishing memories involve crab fishing with his parents, then using a camping stove by the water to make noodles with crab. 

The crabs were "easy to catch as a beginner," said Voong. "If you have a boat, and you can drive anywhere and find a beach and set a trap, and you might find some crabs around."

Asked how sailors visiting from other countries are treated under its regulations, DFO said its officers have a range of compliance measures, including seizure of items and making arrests. 

Officers were "assessing the video and verifying the information," it said.