MONCTON, N.B. -- Every day at airports across Atlantic Canada, five government aircraft have begun to take to the sky, hunting for endangered North American right whales in a huge swath of ocean.

Spotters are covering an area of 460,000 square kilometres, and Jean-Francois Gosselin, a biologist with the Fisheries Department, said they have to be efficient.

So far this year they have spotted 27 right whales, with the goal of keeping them alive.

"The survey has been designed to look where we most expect to see those right whales. This is based on previous sightings of right whales from previous years," he said Wednesday as officials from Fisheries and Transport Canada met reporters to discuss measures to help detect and protect the whales.

The increased measures follow the deaths of 18 North Atlantic right whales in Canadian and U.S. waters last year, mainly due to collisions with ships or entanglements in fishing gear. There are believed to be fewer than 450 of the whales remaining and, of those, there are only about 100 breeding females.

The aircraft are, as weather permits, making daily flights over the Bay of Fundy, the Scotian Shelf, the Gulf of St. Lawrence and the southern coast of Newfoundland.

Gosselin said they are using high resolution cameras but are mainly relying on the skill of trained observers who will spend hours each day, staring down at the water.

"The planes are flying between 800 feet and 1,500 feet off the water and the observers are just looking out the windows and visually detecting whales," he said.

Bubble-shaped windows allow observers to look down at the water.

Hydrophones are also being used in key locations to detect the sound of the whales under the water.

Aside from the five observation aircraft, officers on fisheries patrol flights will also report whale sightings, and a plane from the U.S. National Oceanic and Atmospheric Administration will be looking to identify whales later this summer.

Gosselin said they hope to improve management methods for this year and coming years.

"The objective of the aerial surveillance is to provide estimates of abundance and presence of right whales in the shipping lanes and the fishing areas," he said.

"Also there's a science objective to have a more global understanding of the occurrence, distribution and abundance of right whales through the season on the east coast of Canada."

Six fishing areas in the Gulf of St. Lawrence were closed to several fisheries as of May 22, including snow crab, rock crab and lobster.

The department is enforcing a static closure zone in the Gulf of St. Lawrence along New Brunswick's northern coast until June 30.

DFO is also enforcing dynamic management closures, which will shut down fishing activities for a minimum of 15 days when there is the confirmed presence of North Atlantic right whales.

Fishermen have expressed concerns over the financial impact of the closures.

However, DFO said despite the ongoing fishery closures, the current value of the snow crab fishery this year is higher than it was at the same point in 2016.

The department said landings -- or catches of snow crab -- are valued at approximately $148 million so far for 2018, compared with $112 million for the same point in 2016.

The average price for snow crab in 2016 was $8.19/kg, whereas so far this year the price is estimated at $11.02/kg.

DFO said about 61 per cent of the total allowable catch for 2018 has now been landed, as compared with 68 per cent for the same point in 2016.

The department added that the 2017 snow crab season was an exceptional year during which the total allowable catch hit the historic high of about 40,000 tonnes.

It's been reduced to roughly 22,000 tonnes this year, similar to 2016.

Gosselin said observers on the planes know the impact of their reports and how important it is to be accurate.

"That's why we want to make sure we've done the training properly and we want to make sure that we are detecting the animals," he said.

"That's why we are circling back to identify the right whale properly before we transmit the information to Transport Canada and the Fisheries managers to shut down fishing zones or reduce the speed in shipping lanes," he said.