The applicability of the Elzone particle counter to the determination of marine bacterial biomass was investigated. The biomass of bacterial pure cultures and a mixed natural population were followed by using the particle counter, a CHN analyzer, and an ATP analyzer. The particle counter showed the precise size distribution of number and volume of submicron-size particles in seawater. For the p...

The electrochemical determination of nitric oxide in seawater with microelectrodes is reported in this paper. Two electrodes, ISO-NOPMC microsensor and modified platinum microelectrode, are evaluated for their performance in seawater. The peak current is found to be linear with the NO concentration in the range 1×10-1.2×10 mol/l for both microelectrodes. The detection limit of ISO-NOPMC microse...

At a plunging jet, air entrainment may take place downstream of the impingement perimeter. This study investigates air entrainment and bubble dispersion at vertical circular plunging jets in freshwater, salty freshwater and seawater. The results show lesser air entrainment in seawater plunging jets for identical inflow conditions. The average pseudo-chord sizes are between 4 and 6 mm for all wa...

Ocean acidification and decreasing seawater saturation state with respect to calcium carbonate (CaCO3) minerals have raised concerns about the consequences to marine organisms that build CaCO3 structures. A large proportion of benthic marine calcifiers incorporate Mg into their skeletons (Mg-calcite), which, in general, reduces mineral stability. The relative vulnerability of some marine calcif...

Short- and long-term responses to direct transfer from seawater to freshwater were examined in gill chloride cells of killifish, which developed distinct freshwater- and seawater-type chloride cells in the respective environments. In a short-term response within 24 h after transfer, seawater-type chloride cells forming a pit structure on the apical surface were transformed into freshwater-type ...

Axons freshly dissected from living specimens of the tropical squid Dorytheutis plei have a calcium content of 68 tzmol/kg of axoplasm. Fibers stimulated at 100 impuises/s in 100 mM Ca seawater increase their Ca content by 150/zmol/ kg.min; axons placed in 3 Ca (choline) seawater increase their Ca content by 12 /zmol/kg.min. Axons loaded with 0.2-1.5 mmol Ca/kg of axoplasm extruded Ca with a ha...

Reverse osmosis membrane (RO) is becoming a most popular instrument to desalinate seawater as a result of new developments in membrane technology. The critical factor governing successful long-term reverse osmosis (RO) in desalination plants is fouling caused by the turbidity of seawater, such as by suspended solids, sparingly soluble salts, or biological growth. To reduce the turbidity, the se...

Air-sea exchange of elemental mercury (Hg(0)) is a critical component of the global biogeochemical Hg cycle. To better understand variability in atmospheric and oceanic Hg(0), we collected high-resolution measurements across large gradients in seawater temperature, salinity, and productivity in the Pacific Ocean (20°N-15°S). We modeled surface ocean Hg inputs and losses using an ocean general c...

Euryhaline fishes, such as the red drum (Sciaenops ocellatus), must quickly transition between hyperosmotic and hypoosmotic physiological strategies. When freshwater individuals transition to seawater they are exposed to increased diffusive water loss and ion gain. To maintain osmoregulatory balance these animals must drink and absorb seawater through the intestine, followed by ion excretion at...