Ponds no longer will be used for endangered fish

Dan Kulin

Monday, Feb. 16, 2004 | 11:23 a.m.

Water will return to four man-made ponds at a Boulder City park during the next four weeks, but the endangered fish that had filled those ponds for almost 10 years won't.

The decision to stop using the ponds to raise the endangered razorback suckers and bonytail chubs is at least in part due to area residents dumping goldfish into the ponds, officials said. The goldfish competed for food with the endangered Colorado River fish and contributed to the difficulties the endangered fish faced in recent years in the ponds.

Since 1995 the Bureau of Reclamation used the ponds at the city's Veterans Memorial Park to raise the endangered fish from larvae until they were 10 to 12 inches long. When they had grown to that size they were put into Lake Mohave.

For years the fish farm at the ponds was considered a success. But the number of fish large enough to move into the lake has dropped dramatically in recent years, Bureau of Reclamation spokesman Bob Walsh said.

For example, in 1998 the bureau pulled 3,500 razorback suckers from the ponds. In 2002, the number dropped to 500, and last year the bureau took only 200 razorback suckers from the ponds, Walsh said.

"The reasons for the decline include the cattails, gold fish, and other unknown reasons," Walsh said. "It's hard to point to just one reason, but the other fish and the vegetation were certainly contributing factors."

The bonytail chubs are an extremely rare species to find, even in the ponds, he said. Walsh said he did not know how many bonytail chubs were taken from the Boulder City ponds over the years.

Walsh said the decision to leave the Boulder City ponds was essentially a business decision.

The bureau is budgeted to spend $400,000 to raise the fish this year, with the fish raising concentrated in about seven ponds, including two fish hatcheries on the Arizona side of the Colorado River and four or five ponds along the shores of Lake Mohave.

"We can get 10,000 fish now for what we (previously) could get 2,000 for," he said.

The goal is to restore the Lake Mohave razorback sucker population to 50,000 fish, and since the early 1990s the bureau has put 80,000 razorback suckers into the lake, he said. However, only about 25 percent of the fish survive the relocation.

The state, the Bureau of Reclamation and the city got together to create a wetlands that is made up of the five ponds, four of which were used to raise the fish, and a stream. In addition to raising the endangered species, the man-made wetlands cleaned treated waste water from the city sewer plant, which is used to irrigate the adjacent veterans cemetery.

The ponds are not fenced off, but signs warn people not to put any other fish or animals into the ponds because of the endangered species in there.

The four ponds used to raise the fish recently were drained so the city could attack reeds that had overgrown the ponds and to fix a pond lining.