The Campobello Whale Rescue Team has successfully removed some of the fishing gear from one of three entangled North Atlantic right whales.

Efforts continued Friday to free three entangled right whales in the Gulf of St. Lawrence, after some limited success freeing one of the endangered marine mammals on Thursday.

The Department of Fisheries and Oceans said in a news release late Thursday that disentanglement operations successfully removed gear that was keeping one of whales from using its tail when diving.

It said that for the first time in several days, the weather conditions were favourable for searching.

The department said the whale known as number 4423 was seen during a surveillance flight by the U.S. National Oceanic and Atmospheric Administration around 10 a.m., and the Campobello Whale Rescue Team then began disentanglement operations.

Those efforts had to be halted when it got dark.

Contacted late Friday afternoon, DFO officials were not able to provide any update.

Number 4423 was first seen entangled on July 4 east of Miscou Island, N.B., and is believed to have been snarled before entering Canadian waters, with initial reports indicating it could be a whale first sighted in April entangled in U.S. waters.

This whale was spotted by the Canadian Coast Guard with a rope around its tail and thought to be dragging something heavy.

Surveillance flights continued to search for the two other entangled right whales that were recently observed in the Gulf of St. Lawrence.

Whale number 4440 has been spotted several times since it was initially seen entangled on June 29, but a disentanglement operation has not been possible, while the third entangled whale first spotted on July 4 by a Transport Canada surveillance flight east of Quebec's Gaspe Peninsula has not yet been identified.

A search and rescue attempt for these entangled whales was hampered Wednesday because of bad weather.

The search and rescue operations involve several organizations and people including on-water support from fishery officers, as well as a research vessel from the New England Aquarium.

Joe Gaydos with the SeaDoc Society out of the University of California, Davis, said these search and rescue efforts are another example where extreme measures to help individual animals in such a small population can benefit not only those individuals but also the long survival of this endangered population.

The department said locating these three right whales is a challenging task because they spend a significant amount of time under water, making it difficult to observe them from the air.

Martin Haulena, head veterinarian at the Vancouver Aquarium Marine Science Centre, said earlier disentanglement techniques can be successful if they can get to the whales although the process is dangerous, complicated and weather-dependent.

In the last few weeks, six whales have died in Canadian waters and necropsies showed that three of the deaths were due to vessel strikes.

A federal study said the measures taken to prevent the animals from being hit by ships and getting caught in fishing gear may not be enough to keep them from being hurt or killed in Atlantic waters.

Several measures have been implemented by Transport Canada and Fisheries and Oceans Canada to protect these animals, including increasing surveillance, expanding slowdown zones and changing the rules that trigger fishing shutdowns.

The whales number only about 400.

Gaydos however said the department's "multi-pronged approach" is spot on.

"Long term solutions to reduce entanglement like the static zone and changes in fishing gear confirmation are essential," Gaydos said.

"Short term heroic efforts like disentanglement are essential to give the new management efforts time to work."