How the DWR discovers and manages water bodies affected by quagga or zebra mussels

The DWR has developed a classification system to define the Quagga and Zebra mussel status of the Utah's water bodies. Many Utah waters are suitable in size and depth for use by motorized boats, some are not. The classifications do not differentiate based on boat use; they simply addresses presence or absence of invasive mussels by describing conditions to be met as "unaffected" or "affected" water bodies.

Quagga and/or Zebra mussels breed via open water broadcast spawning. Once spawned, they quickly develop into a microscopic larval form veliger, settling onto suitable surfaces as they gain weight and can no longer float within a few days to weeks. Although an adult female may produce 30,000 eggs per breeding cycle, more than 99 percent of the progeny perish prior to attaining adulthood. The mussels typically grow 1 mm per month under suitable conditions, and can breed after growing to 6 mm in size (about the size of a sunflower seed). Adults average 20 mm in size (about the size of your thumbnail), and may live for two to three years, rarely four. So monitoring for discovery utilizes special nets to collect plankton samples to capture the microscopic veligers. Beach/shoreline and underwater searches are used to collect juvenile and adult sized specimens for identification. All monitoring occurs when the water temperature is suitable for peak spawning of Quagga or Zebra mussels (59–63° F). At unaffected waters monitoring occurs once per year. However, at affected waters monitoring occurs monthly during the boating season. And, monitoring follows guidelines the U.S. Bureau of Reclamation (BOR) developed in consultation with the 100th Meridian Initiative and the Western Regional Panel. The BOR's lab in Denver, Colorado conducted the microscopy analysis, Clean Lakes, Inc. in Boise, Idaho, conducted the FlowCam analysis, and Pisces Molecular in Boulder, Colorado conducted the molecular assessments.

Regardless for the status of invasive mussels in an unaffected or affected water body, all boaters launching in Utah, must properly fill out and display a Decontamination Certification Form in plain view within their launch vehicle. Additionally, boaters are either advised by signs or sometimes by boat inspection technicians working during high use periods of the boating season to always decontaminate their wetted equipment upon departure, since it may take several years to recognize that the water body has become affected by invasive mussels. The purpose is to contain invasive mussels, if present, to the water body, disallowing their inadvertent spread to other water bodies.

Water bodies with an "inconclusive" status evidence at least one larval form veliger collected via a plankton tow net sample, which was believed to have been observed via microscopy. However, two independent molecular assessments of a tissue sample using a polymerase chain reaction (PCR) to assess the Cytochrome Oxidase (COX) 1 gene for mitochondrial deoxyribonucleic acid (DNA) and the intervening transcribed sequence (ITS) of region 1 for ribosomal DNA were unable to confirm the observation. Boaters using an inconclusive water body are either advised by signs or by boat inspection technicians working at least 40 hours/week during high use periods of the boating season that the water body may be affected by invasive mussels, encouraging the boaters to decontaminate their wetted equipment upon departure.

Water bodies with a "detected" status evidence at least one larval form veliger collected via plankton tow net sample and observed via microscopy. Plus, two independent molecular assessments of a tissue sample using a polymerase chain reaction (PCR) to assess the Cytochrome Oxidase (COX) 1 gene for mitochondrial DNA and the ITS of region 1 for ribosomal DNA confirmed the observation. Boaters using a detected water body are regulated under authority of a water specific control plan (Rule R657-60). Boaters are advised by signs and by boat inspection technicians working approximately 16 hours/day, 7 days/week during high use periods of the boating season that the water body is affected by invasive mussels, demanding the boaters to decontaminate their wetted equipment upon departure.

Water bodies with an "infested" status evidence a juvenile or adult sized mussel having been or is present. They were identified by at least two recognized experts observing the specimen or a suitable photo. Additionally, verification for a tissue sample has occurred as per the aforementioned molecular discussion for "detected" waters. Larval form veligers may be present, but are not necessary for this classification. Boaters using an infested water body are regulated under authority of a water specific control plan (Rule R657-60). Boaters are advised by signs and by boat inspection technicians working approximately 16 hours/day, 7 days/week during high use periods of the boating season that the water body is affected by invasive mussels, demanding the boaters to decontaminate their wetted equipment upon departure.

Water bodies with a control plan each require the following:

1. Arriving boaters are inspected and those used within the prior 30 days on a Quagga or Zebra mussel affected water are compelled to be decontaminated when needed.
   Note: Boat launch may be hastened by making sure the boat is cleaned, drained and completely dry before arrival at any water body in Utah.
2. All departing boaters are required to decontaminate.
   Note: Preferably, boaters will clean and drain their boats and other wetted equipment as they remove it from the water body. Then, they can dry their boat and equipment at home before another launch. However, professional decontamination services using scalding hot water are available without cost at or nearby to the water body.
3. Boaters previously using water bodies with a "detected" status as the last water visited and returning to that same water body only, can do so without drying out their equipment, but boats must be clean and drained of all raw water.
   Note: Expect to be closely inspected if your boat and equipment are wet.