Yellow Perch Production and Harvest Strategies for Semi-Permanent Wetlands in Eastern South Dakota

Natural production and harvest of yellow perch Perca flavescens within small semi-permanent wetlands in eastern South Dakota is highly variable. Many factors have been attributed to variable natural production including lack of suitable spawning habitat, food availability and competition for resources. Studies were conducted in 2002 and 2003 to determine the influence of introduced substrate, food availability, and competition on the potential production capabilities of small, semi-permanent wetlands. A study was also conducted to investigate methods to improve harvest efficiency in these smaller wetlands. Spawning substrate primarily functions in determining hatching success of yellow perch. In systems lacking adequate, natural spawning substrates, the addition of introduced structures may enhance yellow perch survival. I quantified the effects of introduced conifer tree reef location, age, and type on yellow perch egg deposition. In two wetlands, yellow perch preferred to spawn on trees in inshore locations compared to trees in offshore locations. Spawning occurred on both short needle (spruce Picea sp.) and long needle (fir Abies sp. / pine Pinus sp.) conifer trees in both wetlands; however, more egg masses were found on the short-needle spruce trees. Newly introduced and trees from the previous year received similar use in inshore locations, indicating that tree reefs will continue to receive use for a few years following introduction. Based on these findings, introduced tree reefs should be placed throughout the inshore areas of wetlands to increase use. Short-needle (spruce) trees should be used rather than long needle (fir/pine) trees. Tree reefs were effective for the two years of this study; however, reef longevity beyond two years should be examined. Food availability and size are important factors driving survival and growth rates of yellow perch. I measured the effect of nitrogen (urea) fertilizer application on primary production, prey availability, and yellow perch growth in experimental and control ponds. Fertilization increased nitrogen levels and stimulated primary production in experimental ponds. However, effects of fertilizer application on zooplankton and benthic invertebrate abundances were minimal. Yellow perch growth was highest in ponds with increased abundance of Daphnia spp. and Ceriodaphnia spp. and least in ponds with low zooplankton abundance and primarily smaller zooplankton. Fertilization stimulated primary production, which should have increased prey availability and improve yellow perch growth. However, results from this study are inconclusive and further research is necessary to fully understand the effects of fertilizer application on yellow perch growth in eastern South Dakota hill ponds. Competition for limited food resources can be an important factor influencing survival and growth of age-0 yellow perch. Age-0 yellow perch and black bullhead Ameiurus melas have similar food habits and potentially compete for similar resources. Potential interspecific competition between age-0 yellow perch and black bullheads was assessed in an enclosure experiment by examining growth responses. Growth rates of yellow perch and black bullheads were not decreased by the presence of the other species, indicating that interspecific competition was not occurring at the stocking densities used in my study. Instead growth rates were similar or greater for each species when the two species were combined, indicating that intraspecific competition may be a more important density-related factor influencing yellow perch and black bullhead growth. Prey selection by yellow perch and black bullheads did not shift in the presence of the other species further dismissing interspecific competition. Under conditions of limited prey resources these species may possibly compete; however, it is more likely that intraspecific competition exerts more influence on yellow perch and black bullhead growth. Success and efficiency of trap and transfer operations are influenced by the ability to quickly collect target fish and transport them to a recipient water body. Improving efficiency of fish collection methods should be directed toward reducing stress and mortality of transferred fish, and reducing trap and transfer costs. I compared the efficiencies of gear types (modified fyke nets and cloverleaf traps with and without light attractants) used for harvesting small yellow perch (age \u3c 2) and minimizing the bycatch of black bullheads and large yellow perch (age \u3e 2). Due to the small openings, cloverleaf traps captured significantly fewer black bullheads than fyke nets and captured no large yellow perch. Fyke nets were more efficient at capturing all available sizes of yellow perch, but also captured substantial numbers of black bullheads. Light attractants increased catch rates of yellow perch in cloverleaf traps set at night. Incandescent lights increased catch rates in fyke nets, but cyalume glowsticks were not effective. Cloverleaf traps and light attractants can help to improve efficiency of yellow perch collection methods, reducing effort associated with sorting out by catch and reducing stress and mortality to transferred fish. Cloverleaf traps can also be placed in offshore locations unlike fyke nets, increasing the amount of area being fished and increasing daily harvest