Fish relocated at Ghost

May 19, 2015

Lowering water levels means relocating the fish

Teams work diligently to capture fish and release them downstream

As part of our agreement with the Government of Alberta to modify operations at the Ghost reservoir for flood mitigation purposes, we are lowering the water by approximately six meters from our typical operating elevation of approximately 1191 meters.

Lowering water levels can leave fish isolated in shallow pools where temperatures are too high and oxygen levels are too low for them to survive for extended periods of time. Teams have been working diligently for the last two weeks to capture fish and relocate them to other areas of the reservoir where they’re not at risk of being stranded. Species relocated to other areas of Ghost Lake include brown trout, mountain whitefish, burbot, longnose and white suckers and various types of minnows.

LEARN MORE: Lowering Ghost Reservoir FAQ

“The varying topography of the of the reservoir bed means that fish can’t swim easily to areas where the larger pools of water remain when water levels are reduced,” says Glenn Isaac, manager, Environment, Health & Safety for hydro.

“We have lowered the levels very slowly over the past two weeks to make sure the fish aren’t left in the pools too long to the point where they’re at risk. Our teams have been working every day to get every fish in every pool.”

Environment is top of mind

Fish relocations are something TransAlta does as part of ensuring we minimize our impact to the environment. Successful large scale fish relocations occurred at our Spray plant in 2011 — a result of flows being bypassed to an infrequently used spillway during an outage — and at Cascade plant after the 2013 flood following the historic activation of the spillway. On top of that, TransAlta conducts routine, smaller-scale fish relocations at the Bighorn facility as a component of the annual dam safety program.

“Every year in about late May, we do a fish relocation in Bighorn due to flow reduction events associated with dam safety inspections,” says Lora Brenan, director, hydro.

“Last year, we moved about 200 fish and we expect to do the same this year. Fish relocation is a part of our operations and we plan for it so we can mitigate any impacts to the natural environment.”

How does it work?

Teams of biologists use electrofishers, seine nets, hand nets and minnow traps to collect the fish in an area and place them in holding pens where they can recover and be inventoried (size and type) prior to being taken downstream and released. In certain areas of shallower water, fish can be scooped up with small nets, or by hand in some cases, to capture them and relocate them.

“By using a variety fishing techniques, we’re able to capture the various types and sizes of fish present, and the work is being done in a manner that minimizes stress to the fish while maximizing the survival rate of those present in the area. The workers conducting the salvage are trained professionals with many years of experience on operations similar to this,” explains Isaac.


May 19, 2015