Invasive baitfish present good and bad news for Colorado River anglers
There is a new species of baitfish that is now well established in all of the lakes on the Colorado River, and some anglers believe it is one of those rare cases where an accidental stocking has actually benefited other species of fish in the lakes.
They are called gizzard shad (Dorosoma Cepedianum), and this fast-growing, plankton-eating, non-native baitfish has caused quite a stir among fishery biologists and anglers alike.
It is believed that the first gizzard shad were introduced to the Colorado River system in 2000 after some of the shad were unintentionally stocked at Morgan Lake in northwestern New Mexico.
The shad escaped that lake and made their way downstream into the Colorado River system.
Gizzard shad first appeared in Lake Mead in 2007, according to C. Douglas Nielsen, a writer for the Las Vegas Review-Journal.
Since then, gizzard shad "have displaced threadfin shad as both the primary forage fish of the lake and the live bait of choice for many anglers," said Nielsen, who is also a biologist with the Nevada Department of Wildlife.
This baitfish, a member of the herring family, grows so rapidly that it creates a good news/bad news scenario for anglers.
The good news is that predatory fish - striped bass, catfish, and largemouth and smallmouth bass - predate on the young gizzards.
The bad news is they grow so rapidly that they become too large for the average predatory fish to eat after a couple of years.
Essentially they grow themselves out of the food chain, except for huge striped bass that can eat them even when they reach 1 or 2 pounds.
The gizzards have become a staple for these large stripers. Anglers in the Nevada Striper Club have figured out that when using large gizzard shad for bait, either trolling or drift fishing with them will snag big fish.
The NSC holds a tournament each month on the lake.
Their tournament starts at 5 p.m. Friday and ends on noon Sunday. Anglers can weigh in just four fish.
In February, the winning weight for four fish was more than 43 pounds, and in March, the winners brought in more than 47 pounds of striper with just four fish.
And the winning team didn't have the largest striper taken in the tournament. Nope, that honor went to another team that had a 22-pound fish!
So how does one get this "magic" bait?
Not in stores.
The only way to get this baitfish is to go out and use a casting net no larger than 4 feet in diameter, and catch them in a few areas of the lake.
And once again, some of the NSC's anglers have mastered that art of catching them and keeping them alive.
They use specially designed bait tanks in their boats - giant live wells, if you will - that keep the fish alive with constant aeration from pumps that move oxygenated water from the lake into the small barrels that hold the fish.
Both Nevada and Arizona have laws prohibiting these fish from being transported live on land. But if they are transported in a boat on Lake Mead in one of those huge live wells, there are no restrictions on transporting them around the lake.
The only way for local anglers to legally possess live gizzard shad in the upper end of Lake Mead (South Cove) is to catch them there or transport them by boat. And a boat trip from Government Wash is a long way to South Cove.
There are currently no rules that prohibit the transportation of dead gizzard shad from Nevada to Arizona. They can be used as bait in both states.
While many anglers see the gizzard shad as a boon to fishing in the Colorado River lakes, Arizona fisheries personnel are not so happy with them.
"This species looks like a threadfin shad on steroids," said Kirk Young, fisheries chief for the Arizona Game and Fish Department. "These wide-bodied invaders are shaped like footballs and can readily grow past the size where they are available to most sport fish as forage."
Gizzard shad grow to about four inches in length during the first year, and grow rapidly to 9-14 inches in two years, and can ultimately grow in excess of 20 inches.
Anglers in the NSC have caught gizzard shad that weighed up to 4 pounds and were longer than 22 inches.
Besides using them as live bait, anglers have found that these slimy, smelly fish are excellent as cut bait, and many anglers use one-inch pieces of gizzard shad instead of anchovies as a bait of choice for stripers.
The skin is tough and the flesh stays on hooks a lot longer than anchovies do.
One angler told me that it is not unusual to catch five to 10 stripers on one piece of gizzard shad. With anchovies, even if they are frozen, it is usually one and done.
Gregg Cummins, a sport fish biologist for the Arizona Game and Fish Department's Region III, agreed that the gizzard shad are in the lake to stay and that gill net studies are showing that these shad have increased at an alarming rate. Plus, these invasive species are getting quite large in the plankton-filled lake.
"The largest gizzard that has been caught in our nets weighed 8.9 pounds," Cummins said. "We are catching them in nets all over the lake, but we have found a large number of them in Hualapai Bay."
Cummins suggested that area if anglers want to net live bait. They should also get a copy of the Arizona fishing regulations and read them before going on the lake.
The gizzard shad are here to stay, and anglers who use them will find that they are an excellent bait for striped bass and catfish on Lake Mead.