Local-scale ecological information is critical as a sound basis for spatial management and conservation and as support for ongoing research in relatively unstudied areas. We conducted visual surveys of fish and benthic communities on nine reefs (3-24 km from shore) in the Thuwal area of the central Saudi Arabian Red Sea. Fish biomass increased with increasing distance from shore, but was genera...

Anaerobic ammonium oxidizing (anammox) bacteria are responsible for a significant portion of the loss of fixed nitrogen from the oceans, making them important players in the global nitrogen cycle. To date, marine anammox bacteria found in both water columns and sediments worldwide belong almost exclusively to "Candidatus Scalindua" species. Recently the genome assembly of a marine anammox enric...

The structure of population boundaries and the biological dynamics that control the edges of major biogeographic regimes are two fundamental questions in biological oceanography with profound consequences to questions ranging from local variations in the marine ecosystem to features in the optical and acoustic properties of the ocean environment. Facing these problems also provides a unique ave...

[1] Nitrification rates, as well as the relationships between rates and ammonia oxidizer abundance (both archaeal and bacterial), were investigated in the Arabian Sea. Ammonia oxidation rates were measured directly using N-NH4 + stable isotope additions in gas-impermeable, trace metal clean trilaminate bags (500 mL) at in situ temperature. Tracer incubations were performed at three stations at ...

[1] Ambient aerosol samples were collected over the Arabian Sea during the month of March 1997, aboard the German R/V Sonne, as part of the German JGOFS project (Joint Global Ocean Flux Study). This is the third study in a series of analogous measurements taken over the Arabian Sea during different seasons of the monsoon. Dichotomous high volume collector samples were analyzed for anions and ca...

Intact core tetraether membrane lipids of marine planktonic Crenarchaeota were quantified in water column-suspended particulate matter obtained from four depth intervals ( approximately 70, 500, 1,000 and 1,500 m) at seven stations in the northwestern Arabian Sea to investigate the distribution of the organisms at various depths. Maximum concentrations generally occurred at 500 m, near the top ...

Nutrient characteristics of four water masses in the light of their thermohaline properties are examined in the eastern Equatorial Indian Ocean during winter, spring and summer monsoon. The presence of low salinity water mass with "Surface enrichments" of inorganic nutrients was observed relative to 20 m in the mixed layer. Lowest oxygen levels of 19 microM at 3 degrees N in the euphotic zone i...