"The very biggest change is in smallmouth bass. They used to be small, numerous, hungry and extremely catchable," Gustaveson said. "You could catch hundreds a day, the size was not great, but you could always catch fish. Now, with the increased forage fish, the biggest change is that it is not easy anymore. You have to work to catch fish. So when you fix a reservoir so that it is more in the favor of the fish, anglers suffer. When fish are hungry anglers are in charge."

But, when anglers do catch fish they are likely to be larger and healthier.

"Absolutely," said Gustaveson. "The quality has gone up and the quantity is still really good."

The biggest smallmouth handled during the netting effort tipped the scales at just over 2 pounds. The smallmouth composed nearly one-fourth of the total number of fish sampled in the two-day collection.

The benefits of a second, unscheduled forage fish have added many advantages to Lake Powell. With the gizzard shad there is now more food to go around. The cornerstone forage of the lake is still the threadfin shad. However, at maturity this fish may reach only 5 to 6 inches in length, well within the diet of even of the largest striped bass predator.

The gizzard shad, on the other hand, are only in the forage game for the first two years of their lives. They will reach 5 inches by their second year, and by age 5 — as seen from those collected during the sampling effort — they can reach 17 inches and more at maturity. That puts them well beyond the reach of any predator in the lake.

The upside to their larger size is that they will likely increase the size of the largest striped bass because they can forage on a greater number of larger gizzard shad for a longer period of time. Instead of seeking out large carp that may be in shallow water and be too difficult for larger stripers to enter, the larger gizzard shad will stay in the same general area as the stripers. It is not unlikely that new state records for stripers, smallmouth, largemouth bass and other sport fish could be set at Lake Powell.

Compared to threadfin shad, gizzard shad like onshore areas. The bigger fish are more likely to be caught in the gill nets and so their numbers are overestimated. In the overall scheme the threadfin shad are estimated at 75 percent vs. 25 percent for the gizzard shad. Because the large adult gizzard shad, like the 17-inch ones collected on this trip, have no predators they showed up in disproportionate numbers in the fall surveys.

Even though biologists were encouraged with what they collected in the gill nets throughout the lake, there were other indicators that the lake will shift again.

With so many large striped bass, Gustaveson feels the fishery is at its peak again and a decline is coming.

"The threadfin are going to have a periodic collapse in their population. At that point these large gizzard shad that we are finding will still be there and still provide good forage and hold the other game fish over until the threadfin can come back," Gustaveson said.

"The boom-and-bust period with the stripers may be over. Right now though they are producing on a tremendous rate, and hopefully there will be enough shad to reduce any impact."

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Deseret Morning News outdoors editor Ray Grass contributed to this report.