Net drift in an atypical estuary, Long Island Sound
Long Island Sound is an estuary with two-layered flow at the eastern opening to the ocean and a salinity gradient of about 5 parts per thousand between the eastern and western extremes. Tidal currents, wind-driven circulation, and river inflow and fresh water influx are investigated as factors affecting the net drift. Current measurements in eastern Long Island Sound indicate that the tidal circulation features that predominate there do not normally affect the net drift at the New Haven dump site. Drifter returns and a numerical model indicate that seasonal prevailing winds seem to be the primary cause of the net drift in central Long Island Sound.
The tides of the East River, New York
The East River, New York, is a cooscillating tidal strait connecting New York Harbor to western Long Island Sound. Linear wave theory is applied to the river in an attempt to interpret the tidal characteristics. The theory accurately describes the observed longitudinal variation in amplitude of the tidal current, but the simple model used does not adequately predict the amplitudes of the tidal heights or the overtides. The frictional resistance to flow through the river is characterized by an effective value of De Chezy's coefficient of ∼26 m½ s−1. Tidal current records gathered over a 5-day period from a linear array placed across the Upper East River have been analyzed to investigate the harmonic content of the tidal transport. The semidiurnal frequency and its third harmonic (M6) are dominant.
Sustainable production of toxin free marine microalgae biomass as fish feed in large scale open system in the Qatari desert.
Mass cultivation of microalgae biomass for feed should be cost effective and toxin free. Evaporation loss in Qatar can be as high as 2 cm/d. Hence, production of marine microalgae biomass in Qatar would also require mitigating water loss as there was only very limited groundwater reserve. To address these issues, a combination of four growth conditions were applied to a 25,000 L raceway pond: locally isolated microalgae strain was selected which could grow in elevated salinity; strain that did not require silica and vitamins; volume of the culture would increase over time keeping denser inoculum in the beginning, and evaporation water loss would be balanced by adding seawater only. A local saline tolerant Nannochloropsis sp. was selected which did not require silica and vitamins. When the above conditions were combined in the pond, average areal biomass productivities reached 20.37 g/m(2)/d, and the culture was not contaminated by any toxic microalgae.