Fisheries officials are worried that a wayward humpback whale is making its way further up a river in Nova Scotia .

The six-metre, 15-tonne whale slipped through open tidal gates at the Annapolis Royal hydroelectric plant this week and into the Annapolis River.

A six-metre humpback swims in the head pond of a hydroelectric plant in Annapolis Royal, NS. (CP Photo)
A six-metre humpback swims in the head pond of a hydroelectric plant in Annapolis Royal, NS. (CP Photo)

Fisheries officials say they're considering playing audio tapes of feeding whales to try to lure the young whale back through the plant's underwater gates and into the Bay of Fundy.

The whale, nicknamed Sluice, hadn't been seen for a couple of days, raising hopes it had left the river. However, on Wednesday, bystanders reported seeing the humpback in the plant's tidal pool.

Jerry Conway, a marine-mammal adviser with the fisheries and oceans department, says, if that's true, the whale could be in trouble.

"The whale may find itself stranded on a mud flat," he says. "The prognosis then is very poor for the whale. Once they strand, or beach themselves, their body weight will collapse their lungs, and it's only a matter of hours."

Conway says he has called his colleagues in the U.S. for advice.

"It has been suggested that, if I was to generate whale vocalizations, or humpback-whale vocalizations, or feeding vocalizations, that this may attract the whale out the gates," Conway says. "We're looking at that technology, and seeing how we can acquire it."

Conway says officials with the department will stay on the river until they find the whale, or they're certain it has returned to its natural habitat.

Until then, the Nova Scotia Power generating station will remain closed.