762 E. Biological Oceanography OLR (1985) 32 (9)

northern fur seal (Callorhinus ursinus). Zoo- logicheskii Zh., 63(12): 1883-1890. (In Russian, English abstract.) All-Union Res. Inst. of Mar. Fish. and Oceanogr., Moscow, USSR.

ELI0. Bottom communities

85:5203 Decho, A.W., W.D. Hummon and J.W. Fleeger,

1985. Melofaana-sediment interactions around subtropical seagrass sediments using factor anal- ysis. J. mar. Res., 43(1):237-255.

Sediments were coarser in a barren sand area than in an adjacent seagrass bed (Thalassia testudinum) in the Florida Keys. Harpacticoids, nematodes, gastro- trichs and turbellarians were more abundant in the barren area, whereas polychaetes were more abun- dant in the seagrass bed. Effects of fine-scale differences in sediment on species abundances could be determined using factor analysis. Dept. of Zool. and Physiol., Louisiana State Univ., Baton Rouge, LA 70803, USA. (mjj)

85:5204 Elmgren, Ragnar et al., 1984. Benthic macro- and

meiofanna in the Gulf of Bothnia (northern Baltic). Finn. mar. Res., 250:3-18.

Results confirm the extreme poverty of macrofauna in the Bothnian Bay as compared to the Bothnian Sea, and especially the well oxygenated parts of the Baltic proper. The meiofauna is not as strongly reduced in the Bothnian Bay, but still less abundant than in the Bothnian Sea. Several meiofauna groups of great importance in the rest of the Baltic seem to have their limit of distribution in the southernmost Bothnian Bay. Dept. of Zool., Univ. of Stockholm, S-106 91 Stockholm, Sweden.

85:5205 Jenness, M.I. and G.C.A. Duineveld, 1985. Effects of

tidal currents on chlorophyll a content of sandy sediments in the southern North Sea. Mar. Ecol.-Prog. Ser., 21(3):283-287.

Transient deposition of suspended organic matter during periods of slack current might provide a food source for benthic animals. Over a 24 h period, changes in chlorophyll levels in the water, on the sediment surface, and in 3 sediment layers were measured. Results not only confirmed this but also revealed that with each tidal cycle, high levels of chlorophyll were alternately being buried in the sediment (to a depth of 5 cm) and then resuspended. Laboratory experiments suggest that this mechanism is related to the formation of sand ripples on the

sediment surface. Davis and Elkins Coll., Elkins, WV, USA.

85:5206 Palmer, M.A. and G. Gust, 1985. Dispersal of

meiofauna in a turbulent tidal creek. J. mar. Res., 43(1): 179-210.

The magnitude of the friction velocity (u) was the primary factor determining benthic meiofaunal abundance in the water column of a South Carolina estuary. Meiofaunal transport resulted from sus- pension of sediment by current scour, followed by mixing and passive transport. Interstitial, epibenthic and burrowing species were identified, with cope- pods, foraminiferans and juvenile bivalves showing the greatest relative abundance. Dept. of Biol., Wabash Coll., Crawfordsville, IN 47933, USA. (mjj)

85:5207 Pichon, Michel and Janice Morrissey, 1985. First

measurements of metabolic parameters on the barrier reef ecosystem at Tulear (Madagascar). C. r. Acad. Sci., Paris, (S~r. III)300(3):99-101. (In French, English abstract.)

A positive but low daily calcification rate (5.3 g C/m 2) and high net production (8.3 g C/m 2) characterize the reef ecosystem. The latter value is attributed to the high cover of fleshy macroalgae. Dept. of Mar. Biol., James Cook Univ., Townsville, 4811 Australia. (msg)

El20. Estuarine, marsh and mangrove communities

85:5208 Boto, K., P. Saffigna and B. Clough, 1985. Role of

nitrate in nitrogen nutrition of the mangrove Avicennia marina. Mar. Ecol.-Prog. Ser., 21(3): 259-265.

Seedlings grown in NHa+-enriched anaerobic soil exhibited markedly reduced (by 50%) N uptake when a nitrification inhibitor was added to the soil. Seedlings grown in aerobic solution showed poor growth, complete lack of fine root development and low N uptake when supplied with ammonium as the sole N source; increased ammonium did not signif- icantly enhance growth in any of the plant com- ponents (leaves, stems, roots). Seedlings supplied with nitrate (only) showed extensive fine root development and good aboveground growth (sig- nificantly enhanced by increased nitrate). Australian Inst. of Mar. Sci., P.M.B. No. 3, Townsville M.C.. Qld. 4810, Australia,