MERCURY CONTAMINATION STANDARDS 247 



responses than are salts of arsenic, lead, or selenium (Weir and Hine, 

 1970). Altered feeding behavior and appetite reduction during and 

 after exposure to mercury salts are documented for teleosts (Klaunig, 

 Koepp, and McCormick, 1975; Rodgers et al., 1951; Salzinger et al., 

 1973) and mussels (Dorn, 1976). 



Mercury-induced growth inhibition is reported for several marine 

 species. The sediment-living, ciliate protozoan Cristigera exhibited 

 reduction in growth during immersion in 2.5 to 5.0 )Ug Hg/liter 

 (Gray, 1974; Gray and Ventilla, 1973); synergistic effects of Hg— Cu 

 and Hg— Pb mixtures on Cristigera growth were also recorded (Gray 

 and Ventilla, 1971). Growth of the colonial, marine hydro id 

 Campanularia flexuosa was depressed during immersion for 11 days 

 in 1.6 to 1.7 iUg Hg/liter; however, growth stimulation occurred in 

 1.0 /ig Hg/liter between days 3 and 7 (Stebbing, 1976). Kelps and 

 other species of algae exhibited growth inhibition during immersion 

 in <5.0 to 350.0 jug Hg/liter (Berland et al., 1976; Boney, 1971; 

 Clendenning and North, 1959; Kayser, 1976; Sick and Windom, 

 1975); similar results were observed for various bacteria (Ben-Bassat 

 et al., 1972). Photosynthesis was reduced in several species of marine 

 alga during immersion in 0.06 to 10.0 jUg Hg/liter; pronounced 

 effects were consistently induced by organomercury compounds at 

 concentrations of 1.0 /ug/liter (Harriss, White, and MacFarlane, 1970; 

 Hopkins and Kain, 1971; Nuzzi, 1972). Recovery of algae to control 

 growth levels after initial mercury -induced inhibition was also 

 reported (Davies, 1974). 



Mercury disrupts various reproductive processes of aquatic 

 organisms, including fecundity, egg deposition, and hatching fre- 

 quency. Concentrations between 32 and 92 jug Hg/liter seriously 

 impair development of sea urchin embryos (Okubo and Okubo, 

 1962; Waterman, 1937); higher concentrations (1,000 /Jg/liter) were 

 necessary to produce a similar effect on marine protozoa (Persoone 

 and Uyttersprot, 1975). Flagellar contractility of sea urchin sperm 

 was inhibited during immersion in 20 to 200 jug Hg/liter (Young and 

 Nelson, 1974); however, mercury was exceeded in this effect by Cd, 

 Cu, Zn, and Fe (Morisawa and Mohri, 1974). Teleost zygotes 

 fertilized and incubated in water containing at least 0.2 /ug Hg/liter 

 exhibit a reduced hatching rate (Kihlstrom, Lundberg, and Hulth, 

 1971). The number of teleost eggs deposited decreases when the 

 concentration of organomercury compounds is 1.0 ^ig Hg/liter or 

 greater (Kihlstrom, Lundberg, and Hulth, 1971). Eggs fertilized in 

 mercury-free water and then allowed to develop under various 

 mercury regimes exhibited increased hatch at 10.0 jug Hg/liter but 

 reduced or negligible hatch at 50.0 jug Hg/liter (Kihlstrom and Hulth, 



