The City of Saskatoon is battling an invasive species in its storm ponds. More than 450 kilograms, or 1,000 pounds, of invasive goldfish of various sizes were collected from three different storm ponds in the city last week. "If you're standing on the edge of the pond on a sunny day, you can often quite easily see the large numbers of goldfish," said Brodie Thompson, an engineering manager with the city. Thompson said goldfish are an "adaptable and tenacious" species, making them difficult to get rid of.