KING 5 flew with the U.S. Coast Guard and Oregon State Police to monitor for illegal Dungeness crab fishery, which is one of the most popular and dangerous fisheries in the Pacific Northwest.

There are boundaries over the Pacific Ocean that the naked eye can't see, but they mark where crabbing is not allowed. Radar shows the Coast Guard pilots and fishermen where crabbing is not allowed.

"What we're looking for isn't necessarily boat fishing. We're looking for the gear they set and then leave," said Trooper Dave Herman. "If we were to see a violation, what we'll see is a string of crab buoys set inside the of the boundary lines."

Colored buoys signal Dungeness crab traps, set to catch one of the country's most valuable crabs.

"A lot of the Dungeness crab is harvested at the beginning of the season,” said U.S. Coast Guard Living Marine Resources Officer Lt. James Bruce. “Because crabs don't migrate, they don't move around. Once you fish a certain area, those crabs don't necessarily come back.”

That's why the fishery is so closely monitored. In 2016, Oregon cited 164 fishermen for breaking the rules. Washington cited 51. The coastal total was 21. Puget Sound's fishery saw 30.

"Anytime that a fishery has significant amount of pressure like the Dungeness crab commercial fishery has, the potential for impact on the resource is greater obviously than a fishery that doesn't have as much pressure on it," Herman said.

Thousands of pounds of crab are harvested illegally each year.

In January 2016, Oregon State Police cited a vessel captain who offloaded approximately 39,000 pounds of Dungeness crab. Of the total, 1,543 pounds of undersized crab were seized. The vessel captain was later convicted of Unlawful Take/Possession of Undersized Dungeness Crab, and forced to pay $2,435 in fines and restitution.