The St. Lawrence River is now officially considered an historic site.

Premier Philippe Couillard designated the waterway as historic Thursday as he admired the view from aboard the Louis-Jolliet during a morning cruise.

“It's unique in the world. What you see behind is probably one of the most beautiful views in Quebec. This waterway is one of the most important in the world,” he said.

The designation is welcome news for biologist and filmmaker Jean Lemire, who's been all over the world in leading a mission on the Sedna IV, a 51-metre schooner.

He calls the St. Lawrence River one of the greatest rivers he's ever seen.

“Absolutely, because the water is very cold and there's a mix of salt water and fresh water, so the biodiversity is exceptional in the St. Lawrence, so we have to protect that,” he said.

The special designation doesn't, however, give the river any special protection.

Still, Couillard said it sends a message that people should be mindful of how they treat the waterway.

“We're not stopping the economic development around the St. Lawrence, no. We're just reminding everyone that it's our responsibility to do it in a sustainable way,” he said.

The special designation for the St. Lawrence River is a first under the province's Cultural Heritage Act, which was adopted in 2012.