O I R 11981) 28 ( 12~ 1~. Biological Oceanograph3 895

[Wadden Sea]. Neth. J. Sea Res., 14(3/4):288- 304.

Investigated was the effect of organic wastewater discharge on gradients of bacteria and macro- and meiobenthic fauna; gradients were associated with changes in sediment organic matter and mud contents and could not be quantified in terms of the wastewater discharge, although a strong local de- crease in 02 saturation was noted. Biol. Centre, Kerklaan 30, 9751 NN Haren, Netherlands. (m~)

81:6765 Wrench, J.J. and R.F. Addison, 1981. Reduction,

methylation, and incorporation of arsenic into lipids by the marine phytoplankton Dunaliella tertiolecta. Can. J. Fish. aquat. Sci., 38(5):518- 523.

During the first 45 rain following exposure to 74As, three previously unreported polar As metabolites (arsenite, monomethylarsonic acid, dimethylarsinic acid) and three arsenolipids were synthesized. Dimethylarsinic acid and the arsenolipids attained equilibrium levels within the 45 min period, indi- cating rapid turnover. Chemical properties of the arsenolipids are described. Bedford Inst. of Ocean- ography, Dartmouth, NS B2Y, 4A2, Canada. (mjj)

E330. Laboratory culture (rearing exper- iments, etc.)

81:6766 Vanhaecke, Paul, Annie Cooreman and Patrick

Sorgeloos, 1981. International study on Artemia. XV. Effect of light intensity on hatching rate of Anemia cysts from different geographical origin. Mar. Ecol.-Prog. Ser., 5(1): 111-114.

Hatching rates increased with increasing light inten- sities; maximal hatching rate attained varied from strain to strain. The hypothesis is discussed that light might act as a diapause inhibitor in marine and freshwater branchiopods. Artemia Ref. Center, State Univ. of Ghent, J. Plateaustraat 22, B-9000 Ghent, Belgium.

E340. Aquaculture (commercial)

81:6767 Bower, C.E. and D.T. Turner, 1981. Accelerated

nitrification in new seawater culture systems: effectiveness of commercial additives and seed media from established systems. Aquaculture, 2411/2): 1-9.

Two ways of reducing the time required to condition a new aquarium in a closed system were compared. Seeding with a 5 or 10% wet filtrant from an established system brought the new filter bed to full nitrifying capacity most rapidly. Commercial bac- terial additives or freshwater culture filtrant were not effective. Sea Res. Found., P.O. Box 7-495, West Hartford, Conn. 06107, USA. (mwf)

81:6768 Dinamani, P. and R.W. Hickman (compilers),

1979/80. Proceedings of the aquaculture con- ference. Held in Wellington, New Zealand, September 1979. Occ. Publ., Fish. Res. Div., Minist. Agric. Fish., N.Z., 27: 104pp; 22 papers.

Conference contributions center on developing prospective species other than rock oysters and mussels (now farmed commercially in New Zea- land). Topics include (but by no means are limited to): various aspects of mussel and oyster culture; aquaculture development potentials and constraints; shellfish exports; ocean ranching and the salmon fishery; silver and grass carp culture; water quality and public health problems. (smf)

81:6769 Lagardere, J.P. and Maurice Sperandio, 1981.

Effects of changes in the level of ambient noise on growth of the shrimp Crangon crangon (Linn6, 1758). Preliminary results, Aquaculture, 24(1/2): 77-90. (In French, English abstract.)

Shrimp grew faster and became less aggressive under conditions of decreased sound pressure. Station Mar. d'Endoume, CREO, Allee des Tamaris, 17000 La Rochelle, France. (izs)

81:6770 Mann, Roger and R.E. Taylor Jr., 1981. Growth of

the bay scallop, Argopecten irradians, in a waste recycling aquaculture system. Aquaculture, 24(1/2):45-52.

A. irradians showed 'specific growth rates compa- rable to or higher' than other bivalves cultured in similar situations, but the high mortality rate must be overcome before such aquaculture is practical. WHOI, Woods Hole, Mass. 02543, USA. (ahm)

E370. Theoretical biology and ecology

81:6771 Bardi, Martino, 1981. Predator-prey models in

periodically fluctuating environments. J. mathl