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Hybrid Striped Bass Fishing

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Published on: Jun. 2, 2000

Last revision: Nov. 5, 2010

is the best way to keep fish from getting off.

THE SHAD CONNECTION: Bigger is not always better

In most Missouri reservoirs, gizzard shad are the most important prey for sport fish, including black bass, crappie, walleye, catfish and white bass. Gizzard shad usually reach maximum sizes of about 9 to 15 inches and can live up to 10 to 12 years. Young gizzard shad grow quickly, so they are most valuable as food for sport fish during their first year of life, when they're less than 5 inches long.

Threadfin shad, a smaller cousin of the gizzard shad, are important prey in reservoirs on the Arkansas border but cannot survive in the colder waters of northern reservoirs.

A recent study by the Conservation Department revealed how important the gizzard shad growth rate can be to sport fish. Gizzard shad can grow so rapidly that they become too large for most sport fish to eat. In Missouri's large reservoirs, gizzard shad usually reach 2 to 6 inches long by the end of their first year.

Crappies can consume shad up to about one-third of their length. For example, a 9-inch-long crappie could eat shad up to 3 inches long. So when shad grow more than 3 inches long their first year, 9-inch crappies are forced to eat other foods because the shad are too large to eat.

Because of their bigger body and mouth size, largemouth bass and white bass can feed on larger shad than crappies. Largemouth bass can eat shad up to about one-half the length of their bodies. Similar to crappies, white bass can consume shad up to about one-third of their length, but they usually grow larger than crappies and thus are able to eat larger shad.

Sport fish usually do not grow as fast when they are forced to eat foods other than shad, especially when their diets consist mainly of invertebrates. For instance, crappies may only reach 7 inches long at 3 years of age in waters with fast-growing shad, compared to 10 inches long where shad grow more slowly. Even largemouth bass and white bass grow slowly in reservoirs where young shad grow fast and get too large for them to eat.

Perhaps the most effective way to reduce growth of young shad for the long term will be to reduce the amount of nutrients and sediments coming into reservoirs. Research shows that young shad quickly grow large in shallow, nutrient-rich reservoirs.

Excessive nutrients and sediments can come from a variety of sources including crop land, confined animal feeding operations, industries and municipal sewage facilities. Runoff containing excessive nutrients and sediments promotes excessive algal growth and sedimentation. That results in rapidly-growing young shad, murky water and shortened reservoir life. - Paul Michaletz

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