The Southern Hemisphere's only population of the mysterious sockeye salmon has started its spawning run in the MacKenzie Country's alpine rivers, providing the region with a new tourist attraction.
In the Twizel River, the sockeye are passing under the State Highway 8 Bridge near Twizel township, and the sight of hundreds of fish moving up the river, and spawning right below the bridge, has become popular with tourists and locals.
The chance to see these fish migrate leads to dozens of people crowding the bridge to look at them.
The sockeye are highly visible, often bursting out of the water in a shower of spray as they scramble across the riffles in their search for the ideal spot in the riverbed to lay their eggs.
Released in 1901 as an attempt to create a sea-run salmon canning industry, the attempt failed when the sockeye never ran to the sea, leaving the Chinook salmon to become the basis for the South Island's successful salmon fishery.