Selenium, at concentrations exceeding 200 parts per million (ppm) (dry weight), has been found in white sweet clover voluntarily growing on beds of fly ash in central New York State. Guinea pigs fed such clover concentrated selenium in their tissues. The contents of the honey stomachs of bees foraging on this seleniferous clover contained negligible selenium. Mature vegetables cultured on 10 percent (by weight) fly ash-amended soil absorbed up to 1 ppm of selenium. Fly ashes from 21 states contained total selenium contents ranging from 1.2 to 16.5 ppm. Cabbage grown on soil containing 10 percent (by weight) of these fly ashes absorbed selenium (up to 3.7 ppm) in direct proportion (correlation coefficient r = .89) to the selenium concentration in the respective fly ash. Water, aquatic weeds, algae, dragonfly nymphs, polliwogs, and tissues of bullheads and muskrats from a fly ash-contaminated pond contained concentrations of selenium markedly elevated over those of controls.

Mechanical and electromechanical barriers played a significant role in the initial attempts to control sea lamprey (Petromyzon marinus) populations in the upper Great Lakes. More recently electromechanical weirs have been used to assess the relative abundance of spawning-run sea lampreys in Lake Superior. Development of an integrated control approach to sea lamprey control has stimulated an ongoing research program to define structural and/or velocity criteria that can be used to design barrier dams that block spawning runs of sea lamprey.Key words: sea lamprey, Petromyzon marinus; physical barriers, burst swimming speed, barrier dam criteria

Ryderˈs morphoedaphic index (MEI: Total dissolved solids, TDS/mean lake depth) was developed empirically as a predictor of fish yield. It generally accounts for 60 to 78% of the variation (corrected sums of squares) in fish yields observed in a set of data. However, no basis for these correlations has been proven or even generally accepted. We demonstrate that two mundane relationships may be the reasons the MEI appears to be valid. Quite simply, large bodies of water tend to produce greater fish yields than small ones, and large bodies of water tend to have greater mean depths than small ones. Mean depth acts as a surrogate for surface area in the MEI; however, surface area alone is a more powerful predictor. It accounts for 94% of the variation in fish yields observed in three combined sets of data reported in the literature. The variation accounted for by the regression only increased to 95% when TDS was added as a predictor.