Fish elevator opened on Shoalhaven River

Where do fish look when they are locked in an elevator together?It is a question that will remain a mystery for a little longer, says the Sydney Catchment Authority's senior environmental manager, Tony Paull.Even so, elevator etiquette was a crucial consideration for the state's first ''fish lift'' officially opened yesterday by the state's Water Minister, Phil Costa."This new fish lift is the largest of its kind in Australia and a direct investment into improving the health of this vital river system," Mr Costa said.The fish lift is being touted as a solution to one of the biggest ecological problems facing one of NSW's most beautiful but troubled rivers - the Shoalhaven.Tallowa Dam, which forms a crucial back-up to Sydney's water supply, has been a Berlin Wall for fish and other aquatic organisms. Only eels and gudgeons have the climbing skills to haul themselves up and over the 43-metre-high wall.The existence of the dam wall is thought to have led to the local extinction of up to 10 native fish species, which have to migrate upstream to complete their life cycle.As part of its program to improve environmental flows on the Shoalhaven, the Government committed itself to somehow getting fish from one side of the wall to the other.A standard fish passage was ruled out as it would have had to have been a kilometre long to be at a gradient that fish could actually use, Mr Paull said.Instead the NSW Government decided to build a fish lift. The idea is simple but bizarre. When fish hit the dam wall they are now met by an enticing flow of water from upstream. When they follow this "attraction flow" they end up being guided into a 2500-litre hopper. The doors are closed 18 times a day and the whole contraption, with fish, water and anything else that ends up in the lift, is carried over the wall and released.The Sydney Catchment Authority has banned angling near where the fish are released and has also established refuge habitats for smaller fish to hide as soon as they are released upstream.Scientists considered installing a camera inside the lift so they could study the fish but in the end decided to settle for making sure there were safe places for prey to hide during the ferry ride over the wall."They can hide and be separate from each other if they don't like the look of their travelling companions," Mr Paull said.Altogether $26 million has been spent on the project - about a third of which has gone on the fish lift component."Once the water warms up in spring we think we are going to see a lot more fish starting to move," Mr Paull said.