1028 E. Biological Oceanography OLR(1986)33(12)

El40. Birds

86:7021 Abraham, D.M., 1986. Observations on the breeding

biology of Sabine's gulls (Xema sabinJ~. Can. J. Zool., 64(4):898-903. P.O. Box 4, Moosonee, Ont. P0L 1Y0, Canada.

El50. Microbiology (communities, pro- cesses; also bacteria, fungi, yeasts, viruses, etc.)

86:7022 Carlucci, A.F., D.B. Craven, K.J. Robertson and

S.M. Henrichs, 1986. Microheterotrophic utili- zation of dissolved free amino acids in depth profiles of southern California Borderland basin waters. Oceanologica Acta, 9(1):89-96.

Utilization rates were most rapid in the euphotic zone and decreased considerably in mid-depth basin waters. Euphotic zone heterotrophs were insensitive to dissolved free amino acid (DFAA) additions as high as 15 nmol/L, but mid-water populations displayed elevated respiration and incorporation rates at DFAA additions > 2 nmol/L. Microhet- erotroph DFAA utilization accounted for 2-11% of euphoric zone primary production. Inst. of Mar. Res., Univ. of Calif., La Jolla, CA 92093, USA.

86:7023 Carlucci, A.F., S.L. Shimp and D.B. Craven, 1986.

Growth characteristics of low-nutrient bacteria from the north-east and central Pacific Ocean. FEMS Microbiol. Ecol., 38(1):1-10.

All isolates were heterotrophs, with optimal doubling times of 2-5 hours, capable of growing in sterile unsupplemented seawater, UV-irradiated seawater, artificial seawater and charcoal-treated artificial seawater. Growth was negatively affected by low oxygen tensions and low temperatures, but not by inoculum size. Inst. of Mar. Resources, Univ. of Calif., La Jolla, CA 92093, USA. (gsb)

86:7024 Fuhrman, J.A., H.W. Ducklow, D.L. Kirchman,

John Hudak, G.B. McManus and Jonathan Kramer, 1986. Does adenine incorporation into nucleic acids measure total microbial production? Limnol. Oceanogr., 31(3):627-636.

Two of the method's assumptions are examined. Size fractionation, autoradiography, and metabolic in- hibition data indicate that the requirement that bacteria, algae, and protozoa have a uniform uptake

and metabolism of added dissolved adenine does not appear to hold. Second, the C:DNA ratio of 50 is too high for natural bacteria, which have a ratio closer to 5. It is concluded that the method probably pro- duced large overestimates of production and that variations may not reflect growth rates, but a combination of activities and ratios of eucaryot- ic:procaryotic biomasses. Mar. Sci. Res. Center, SUNY, Stony Brook, NY 11794, USA.

86:7025 Pel, Roel and J.C. Gottschal, 1986. Mesophilic

chitin-degrading anaerobes isolated from an estuarine environment. FEMS Microbiol. Ecol., 38(1):39-49.

Eight rod-shaped, gram-negative, spore-forming bacteria with complete substrate specificity for chitin and its oligomers were isolated. Chitinolysis was slow and incomplete, occurring in the pH range 5.0-9.0 and producing acetate, ethanol, formate, CO2, H2, and ammonia (maximally under reducing conditions). Ecological implications are explored. Dept. of Microbiol., Univ. of Groningen, Kerklaan 30, 9751 NN Haren, Netherlands. (gsb)

86:7026 Sugahara, Isao, Koichiro Hayashi and Toshio

Kimura, 1986. Distribution and generic compo- sition of denitrffying bacteria in coastal and oceanic waters. Bull. japan. Soc. scient. Fish., 52(3):497-503.

Denitrifying bacteria were enumerated by the M.P.N. method; their number in the surface water ranged from less than 2.0 × 10 t to 3.4 × 102 cells/mL. Almost all (98.1%) of the isolated denitri- fiers (264 strains) were asporogenous gram-negative rods with polar flagella; about 84.8% of the isolates required NaCI for growth. Pseudomonas was the most dominant genus of denitrifying bacteria in the water column. Fac. of Fish., Mie Univ., Tsu 514, Japan.

86:7027 Winn, C.D. and D.M. Karl, 1986. Diel nucleic acid

synthesis and particulate DNA concentrations: conflicts with division rate estimates by DNA accumulation. Limnol. Oceanogr., 31(3):637-645.

Net synthesis of RNA and DNA was observed over 24-h periods at all Pacific Ocean locations inves- tigated, but the actual rate sometimes varied with time of day. It is concluded that whenever possible, daily rates of synthesis should be determined from a series of consecutive incubations conducted over a complete 24-h period. In addition, nonreplicating DNA comprised 75-90% of the total particulate