Eastern Part Of Bay Research Articles

Simulation of Seasonal Hydrodynamic Regime in the Sevastopol Bay and of Assessment of the Self-Purification Capacity of its Ecosystem

The numerical experiments were carried out to assess the hydrodynamic regime of the eastern part of the Sevastopol Bay, subject to the Chernaya River runoff (high- and low-water periods) and the Yuzhnaya Bay, subject to the technogenic load using the hydrothermodynamic block of the numerical three-dimensional unsteady model MECCA (Model for Estuarine and Coastal Circulation Assessment).The simulated hydrodynamic parameters of the selected parts of the Sevastopol Bay were used to analyze the self-purification capacity of their water bodies by calculating the assimilation capacity for inorganic phosphorus. Phosphates suggested as a priority pollutant in municipal and storm runoffs in the water area of the bay and a determining factor of its in the bay eutrophication. At the same time, to neutralize the differences in the water volumes of the studied water areas when calculating the self-purification ability, estimates of the specific assimilation capacity of their ecosystems were obtained.According to the simulations for the eastern apex part of the bay during high-water period, the water circulation in the surface layer contributes to the spread of pollutants throughout the entire water area of the bay. During the low-water period in the eastern part of the bay, currents prevail, directed towards the Chernaya River mouth in the surface and in the bottom water layer both in the northwestern and western wind directions. It contributes to pollutant accumulation in this part of the bay, thus reducing ability to self-purification.Possible reasons for the low self-purification capacity of the ecosystem of the eastern part of the Sevastopol Bay with respect to inorganic phosphorus are analyzed, which are associated both with the volumes of incoming Chernaya River waters during winter high- and summer low-water periods, as well as with the features of the morphometric structure of the water area bottom.For the Yuzhnaya Bay water area, the hydrodynamic regime is defined by a difficult water exchange with the main water area. Ventilation of the waters of the Yuzhnaya Bay is mainly determined by the wind regime, as a result of which the waters are either trapped in the bay or carried out of it, which undoubtedly affects the self-purification capacity of its ecosystem.

New Geographical Record of the Rainbow Runner, Elagatis bipinnulata (Quoy & Gaimard, 1825) (Perciformes: Carangidae) from the Bay of Bengal, Bangladesh

This paper describes the first record of the rainbow runner Elagatis bipinnulata (Perciformes: Carangidae) from Cox’s Bazar, the North eastern part of Bay of Bengal, Bangladesh. Two specimens of E. bipinnulata ware collected on 23 June 2018 from the Bangladesh Fisheries Development Corporation Fish Landing Center of Cox’s Bazar. Morphometric and molecular approaches were applied for identification. Dorsal and anal fins with terminal two rayed finlet, absence of scute, upper jaw ending distinctly before vertical at front margin of eye are the key characteristics to this species. Six spines in first dorsal fin and (24 + 2) fin rays in second dorsal fin; (17 + 2) anal fin rays with one spine present. The morphometric, meristic and molecular analyses thus confirmed the presence of E. bipinnulata in Bangladesh. This report updates the geographical distribution for this species confirming its presence in the coastal region of Bangladesh, and extends the number of marine fish known from the area.

Numerical Simulation of the Exchange Process within a Shallow Bar-Built Estuary

Great South Bay is the largest of a series of interconnected bar-built estuaries on the south shore of Long Island, New York. The depth-averaged barotropic motions in the bay were simulated by using a finite element two-dimensional numerical model. The barotropic motions were driven with astronomical tides, subtidal coastal sea level fluctuations induced by longshore wind stress over the adjacent continental shelf, and local wind stress over the surface of the bay. There was vigorous exchange at tidal frequencies between the western part of Great South Bay and the surrounding waters, but the tidal exchange was heavily damped in the eastern part of the bay. At subtidal frequencies the volume exchange did not exhibit significant attenuation in the interior of the bay. In the eastern part of Great South Bay, the magnitude of the subtidal volume exchange could exceed that of the tidal exchange. The principal mode of subtidal volume exchange was found to be associated with subtidal sea level fluctuations along the coast, which characteristically caused a filling or emptying of the system from all open boundaries of Great South Bay.

Distribution of larvae ofPinnixa rathbuni Sakai (Decapoda: pinnotheridae) in Ise Bay and its neighbouring coastal waters, central Japan part 3. Aggregation of the benthic adult population with reference to the spatial distribution of the planktonic larvae

According to studies made to date, the planktonic larvae ofPinnixa rathbuni, especially the early zoeal stages, have been found mainly in the eastern part of Ise Bay (Pacific coast of central Japan), while the benthic adult population is restricted to the southwestern part of the bay. The present study was made to obtain a better understanding of the origin of the dense population of early zoea found along the coast of the Chita Peninsula in the eastern part of the bay. Field surveys made with a Smith-McIntyre grab from May to November 1981 (every two months) ruled out the possibility that the benthic adult crabs in the southwestern part of the bay migrated to the eastern part of the bay to release their larvae, or that a substantial population of the crabs occurred in the eastern part of the bay. Thus, the larvae may be derived wholly from the benthic adult populations localized in the southwestern part of the bay. The spatial distribution of the early larvae can be explained by assuming that the larvae, released by the benthic adult population in the southwestern part of the bay, are rapidly transported toward the Chita Peninsula and form a dense larval population along the coast in the eastern part of the bay.