09d

• Board Meeting Date: 3/18/2008
• Description: CWCB Director's Report
• Board Meetings - Doc Type: Memo

This winter, additional sampling is planned at Lake Pueblo State Park to determine the degree of
infestation and exact rnussel species. State Parks and DOW are preparing a concerted effort to notify
recreational users at Pueblo Reservoir, and other state parks, about the potential impacts of zebra
mussels.
The Pueblo State Fish Hatchery, which receives its water supply from Pueblo Reservoir, will undergo
testing to determine options to prevent the spread of adult mussels and veligers.
Sampling inspections have been conducted to determine if zebra mussels or larvae are present in the
hatchery unit, but none have been detected. Pueblo Hatchery raises a variety of warm and cold water
species offish (walleye, bluegill, crappie, channel catfish, smallmouth bass, wiper, rainbow, cutthroat X
rainbow hybrid, and brown trout) and distributes these fish across the state each year.
There will be no fish stocking from the Pueblo Hatchery until April this year. Effective water treatment
options exist to eliminate zebra mussel adults and veligers prior to the fish being stocked.
All boaters and other water craft recreational users should take simple, precautionary steps every time
they go to a lake, river or stream.
Before leaving a lake or other waterway, always
CLEAN the hull of your boat.
DRAIN the water from the boat, livewell and the lower unit of the engine.
DRY the boat, fishing gear, and equipment.
INSPECT all exposed surfaces.
REMOVE all plant and animal material.
Remember, many of these aquatic hitchhikers can harm your boat as well. These invaders will attach
themselves to boats and can cause damage to boat motors if they block the flow of cooling water through
the engine.
However, zebra mussels do not pose a known threat to human health. Biologists are concerned that zebra
mussels may cause ecological shifts in the lakes they invade, with consequences to valued wildlife
resources. Because these invasive mussels attach to hard surfaces like concrete and pipes, they will
affect canals, aqueducts, water intakes and dams, resulting in increased maintenance costs for those
facilities.
The zebra mussel gets its name from the black- (or dark brown) and white-striped markings that appear
on its shell. Zebra mussels are native to the Caspian, Black, and Azov seas of Eastern Europe.
These exotic mussels were first discovered in the United States in Lake Saint Clair, Michigan, in 1988
and are believed to have been introduced in 1986 through ballast water discharge from ocean-going ships.
Since their initial discovery, zebra mussels have spread rapidly throughout the Great Lakes and
Mississippi River Basin states and other watersheds throughout the eastern and central United States.
The primary method of overland dispersal of these mussels is through human-related activities. Given
their ability to attach to hard surfaces and survive out of water, many infestations have occurred by adult
mussels hitching rides on watercraft. The microscopic larvae also can be transported in bilges, ballast
water, live wells, or any other equipment that holds water.
They are primarily algae feeders. They feed by filtering up to a liter of water per day through a siphon.
These mussels consume large portions of the microscopic plants and animals that form the base of the
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