'Tens of thousands' of fish likely killed as result of rubber duck race, DFO says

Tens of thousands of adult gaspereau likely died in a fish kill last May at a generating station in Kings County, the Department of Fisheries and Oceans said Thursday.

Determining exact number of fish killed is not possible as many were washed downstream, department says

Gaspereau fish, which are also known as alewives, are shown in this file photo. (CBC)

Tens of thousands of adult gaspereau likely died in a fish kill last May at a generating station in Kings County, the Department of Fisheries and Oceans said Thursday.

The department released the estimate one day after announcing Nova Scotia Power has agreed to pay $50,000 into a federal environmental damages fund for causing the fish kill.

The deaths of the gaspereau — a species of herring also known as alewives — was the result of the utility opening the gate at its White Rock generating station to increase the flow of water for an annual charity rubber duck race.

"The fish were drawn into the generating station when water flow was suddenly increased and then were killed by either strikes from the turbine blades or the sudden change in pressure," Mark McLean, manager of DFO's fisheries protection program, said in a statement to CBC News.

An exact determination of the number of fish killed is not possible, McLean said, as many washed downstream soon after the event occurred.

"Based on the number seen at the site and reports from other witnesses, there were likely tens of thousands of fish killed as a result of the event," he said.

McLean said he did not expect a significant impact on the overall gaspereau population going forward, given the high numbers of fish — more than 1 million — that return to the river each year.

In addition to its $50,000 atonement payment, Nova Scotia Power will no longer participate in the rubber duck race because opening its gate poses a risk to fish.

The charity event has been a part of the Annapolis Valley Apple Blossom Festival for 22 years.

The utility has also agreed to improve its monitoring of migrating fish through the hydro system.