Typically, it takes three to four years for smallmouths to grow to legal creel size, so we can expect this great 2005 year-class to become part of the fishery in 2008 or soon after.

What are the prospects for smallmouths in our river systems in 2006?

"More smaller fish than bigger fish would be my prediction," Lorantas said. "Of course, that is looking at the big picture. Anglers shouldn't take that to mean the fishing will be terrible."

Lorantas pointed out that there are still plenty of bigger smallmouths out there. There may be fewer larger smallmouths for the next few years because of weaker recruitment from 2002 through 2004, but anglers will find good fishing in places if they learn where the bigger bass are lurking.

The big news last year was a bacterial infection that resulted in widespread mortality of smallmouths in the Susquehanna and Juniata rivers. The outbreak was observed primarily in the Susquehanna River from Sunbury to below Harrisburg and in the Juniata River downstream of Lewistown. Lesser problems were reported from the West Branch Susquehanna River, the North Branch Susquehanna River, Loyalsock Creek and Penns Creek.

There were no reports of the problem from other river systems.

The Pennsylvania Fish and Boat Commission worked with the Pennsylvania Department of Environmental Protection, the U.S. Fish and Wildlife Service, the U.S. Geological Survey and the Susquehanna River Basin Commission to compile and analyze data that could help explain why random pockets of young smallmouths contracted columnaris in early summer.

Flavobacterium columnare is a common bacterium in soil and water. It is harmless to humans but can infect all species of freshwater fish. Columnaris is a secondary infection brought on by environmental or nutritional factors that stress fish. In this case, high water temperatures and low dissolved-oxygen levels were probably the stress factors. The same warm water and lower flows that led to the good year-class were probably the major factors in allowing the columnaris outbreak.

Columnaris mortalities are known to occur when water temperatures exceed 65 degrees. At the Susquehanna River, temperatures exceeded 80 degrees during the YOY sampling. While sampling was done in the morning, dissolved-oxygen levels were found to be near the crucial point and were probably lower at night. Of course, young smallmouths inhabit shallow water near shore where these conditions are most extreme.

Some sort of pollution might have been a factor, but this is unlikely because only young smallmouths were seriously impacted. Pollution would probably have affected, all species. Also, the widespread incidences of the outbreak within the Susquehanna Basin appear to rule out pollution.

Even with this problem, the 2005 year-class was the strongest in several years. But with nearly half of the YOY smallmouths in one of the Juniata River samples displaying columnaris infection, biologists are concerned.

"Although we were above average, it's unknown whether that above-average value will continue to maintain itself," Lorantas said. "Whether the mortality associated with that disease will have a lasting effect remains to be seen."