Oil company TransCanada suspended construction of a terminal on a major pipeline along the St. Lawrence River Monday after Canadian authorities classified a nearby population of beluga whales as "endangered."

The arctic white whale, with its distinctive spherical forehead and smiling mouth, is present in and around Cacouna, Quebec where the terminal is planned.

The belugas in the area were labeled "threatened" in the last formal study done ten years ago.

The population was estimated to number less than 1,000 whales, compared to more than 10,000 in 2004, the Committee on the Status of Endangered Wildlife in Canada said in a report.

That puts the whales at "considerably greater risk of extinction" than before, the report said, citing pollution, noise disturbance and industrial development as reasons for the northern whales' decline.

The committee is composed of scientists whose conclusions are submitted to Canada's environment ministry.

As a result of the endangered label, TransCanada halted the terminal construction in Cacouna, the company said in a statement.

The Cacouna terminal was intended to be operational by 2018 as part of the $10.5 billion Energy East pipeline that's planned to connect Canada's east and west coasts.

The decision to delay the construction was made to give the company time to analyze the beluga recommendation and review options for the future, TransCanada spokesman Tim Duboyce said.