Keeping quagga mussels in, not out of, Lake Powell at Glen Canyon National Recreation Area is the new strategy after years of trying to prevent the non-native species' spread into the reservoir have been declared a failure.

Though Park Service officials thought they had been winning the battle against the mussels through mandatory boat checks, back in February they said dropping water levels in Lake Powell revealed a much greater infestation than they had thought existed.

"Thousands of adult quagga mussels have been found in various locations, such as canyon walls, Glen Canyon Dam, boats, and other underwater structures," NRA spokeswoman Denise Shultz said in February. "The majority of mussels found are isolated adults, with additional groupings of small clusters. One adult mussel was found on the south canyon wall of Bullfrog Bay."

Last week the NRA officials said the infestation had grown too large to combat, and that now the strategy would be to prevent boats leaving Lake Powell with mussels onboard.

“Now that the quagga mussels are in Lake Powell, we need to focus our efforts on containing them,” said Superintendent Todd Brindle. “We all put up a good fight for 14 years to keep Lake Powell mussel free, but now we need to work just as hard to protect other lakes and rivers.”

To do that, boat ramp hours will no longer be restricted and green mussel free certificates no longer required. NPS staff instead will focus on checking for evidence of attached mussels on boats entering and leaving the lake. Rangers on the ramps, at the marinas, and along beaches will educate visitors on how to stop the spread of mussels with Clean, Drain, and Dry techniques.

Utah and Arizona state laws require that boat owners decontaminate their vessels and conveyances to avoid the transport of quagga mussels to uninfested waters. Specific information on state laws for Utah can be found at www.wildlife.utah.gov/mussels or for Arizona at www.azgfd.gov/ais.