Officers from DFO's B.C. marine mammal team cut ropes off a juvenile humpback whale that was trapped in fishing gear on June 10, 2009. ((DFO))

The Department of Fisheries and Oceans (DFO) released video Friday of its officers rescuing a juvenile humpback whale after it became tangled in at least 50 prawn traps on June 10 in Knight Inlet, off the central B.C. coast.

Fisheries officers were called in after the whale became wrapped up in 273 kilograms of fishing gear, in addition to the traps.

Humpback whales are listed as threatened under the Species at Risk Act.

Whales caught up in fishing gear can drown from exhaustion or because they are weighed down and cannot surface to breathe.

According to Paul Cottrell, a DFO marine mammal co-ordinator, said it took two hours to disentangle the whale from the gear and the traps, which had a total weight of 455 kilograms.

The whale panicked and started to swim in circles, which made the situation worse.

"It was caught right through the mouth, around through and then draped down so it was pulling down on the animal, " Cottrell said.

Cottrell and two colleagues used specialized equipment from their boat and said they were lucky the whale was not aggressive.

A similar incident of a whale becoming trapped in fishing gear also happened in Knight Inlet in May, and six such occurrences were reported to DFO last year.

DFO oversees a marine mammal response network, which includes a 24-hour hotline to encourage fishing and recreational boaters to report sick, distressed or dead marine mammals and sea turtles.

The number is 1-800-465-4336.