02-24-2007, 12:14 AM
[size 1]PHOENIX - In the light of two more discoveries of invasive species in Arizona lakes - gizzard shad in Roosevelt Lake and bighead carp in Kennedy - Arizona Game and Fish Department biologists are pleading for the public to help prevent such invasions from continuing.
"These latest discoveries of invasive species in our lakes should serve as loud warning bells to water recreationists, especially anglers and boaters, to take simple, but necessary precautions to help prevent the spread of aquatic hitchhikers," says Larry Riley, fisheries chief for the Arizona Game and Fish Department.
Gizzard shad were discovered in Roosevelt Lake during a recent fish survey of the lake. A bighead carp in Kennedy Lake in Tucson was caught by an angler. These two discoveries come on the heels of finding invasive quagga mussels in the Colorado River system of lakes from Mead to Havasu. These mussels can clog water pipelines; affect hydroelectric power operations; damage machinery, such as boat engines; harm fishery resources; and ultimately, cause millions of dollars in damages.
"We are looking at multiple invaders right now and the potential for others. One possible pathway for such invaders is live bait buckets. We are pleading with anglers not to dump their bait buckets in lakes. Those bait buckets can carry unwelcome guests none of us want in our waters," Riley warns.
Gizzard shad, which are also called hickory shad, herring and skipjack, are native to eastern North America, especially in the Mississippi River drainage. They typically grow to 9 to 14 inches in length, but some have been reported to exceed 20 inches. The concern is that these shad will compete with threadfin shad, which are currently eaten by the larger fish in the lake. The threadfin shad population would then decrease, and the gizzard shad would probably grow too large for bass and crappie to eat. This would cause fishing conditions at the lake to suffer.
Gizzard shad were discovered in Lake Powell in 2003 and now are documented throughout the lake. Because gizzard shad can grow quickly and reach sizes too large for even large predators such as striped bass to get their mouths around.
The bighead carp is a member of a family of Asian carp that have been introduced into the United States from their native range in China. While bighead carp are of concern, other Asian carp, such as the silver carp, are of even greater concern. Silver carp have caused considerable worries in the Mississippi River basin.
"Game and Fish Department biologists are evaluating the potential impact and assessing the risks that these unwelcome invaders pose to our lakes," Riley says. "Of immediate concern is investigating the potential pathways to our lakes, so that we can take steps, where possible, to close down such pathways before other invaders are introduced."
Please take these simple precautions:
Drain and dry your livewell and bilge on land. Drain all the water you can from your engine.
Inspect your vessel and trailer, removing any hitchhiking vegetation or critters.<br />
Do not reuse bait once it has been in the water. Remember: Don't dump your bait bucket in the lake.<br />
Wash your boat, trailer and other equipment once you get home. High-pressure washers, such as those found at do-it-yourself car washes, can be effective at washing boat hulls and trailers. [/size]
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"These latest discoveries of invasive species in our lakes should serve as loud warning bells to water recreationists, especially anglers and boaters, to take simple, but necessary precautions to help prevent the spread of aquatic hitchhikers," says Larry Riley, fisheries chief for the Arizona Game and Fish Department.
Gizzard shad were discovered in Roosevelt Lake during a recent fish survey of the lake. A bighead carp in Kennedy Lake in Tucson was caught by an angler. These two discoveries come on the heels of finding invasive quagga mussels in the Colorado River system of lakes from Mead to Havasu. These mussels can clog water pipelines; affect hydroelectric power operations; damage machinery, such as boat engines; harm fishery resources; and ultimately, cause millions of dollars in damages.
"We are looking at multiple invaders right now and the potential for others. One possible pathway for such invaders is live bait buckets. We are pleading with anglers not to dump their bait buckets in lakes. Those bait buckets can carry unwelcome guests none of us want in our waters," Riley warns.
Gizzard shad, which are also called hickory shad, herring and skipjack, are native to eastern North America, especially in the Mississippi River drainage. They typically grow to 9 to 14 inches in length, but some have been reported to exceed 20 inches. The concern is that these shad will compete with threadfin shad, which are currently eaten by the larger fish in the lake. The threadfin shad population would then decrease, and the gizzard shad would probably grow too large for bass and crappie to eat. This would cause fishing conditions at the lake to suffer.
Gizzard shad were discovered in Lake Powell in 2003 and now are documented throughout the lake. Because gizzard shad can grow quickly and reach sizes too large for even large predators such as striped bass to get their mouths around.
The bighead carp is a member of a family of Asian carp that have been introduced into the United States from their native range in China. While bighead carp are of concern, other Asian carp, such as the silver carp, are of even greater concern. Silver carp have caused considerable worries in the Mississippi River basin.
"Game and Fish Department biologists are evaluating the potential impact and assessing the risks that these unwelcome invaders pose to our lakes," Riley says. "Of immediate concern is investigating the potential pathways to our lakes, so that we can take steps, where possible, to close down such pathways before other invaders are introduced."
Please take these simple precautions:
Drain and dry your livewell and bilge on land. Drain all the water you can from your engine.
Inspect your vessel and trailer, removing any hitchhiking vegetation or critters.<br />
Do not reuse bait once it has been in the water. Remember: Don't dump your bait bucket in the lake.<br />
Wash your boat, trailer and other equipment once you get home. High-pressure washers, such as those found at do-it-yourself car washes, can be effective at washing boat hulls and trailers. [/size]
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