This study characterizes the seasonal reproductive cycle of female round stingrays (Urobatis halleri) in an open coastal site at Seal Beach, CA and a protected estuary at the Seal Beach National Wildlife Refuge (SBNWR). Female round stingrays were sampled from August 2004 to July 2006, and assessed for reproductive parameters (GSI, maximum ova diameter, pregnancy status) and sex steroid (estrad...

BACKGROUND External nutrient discharges have caused eutrophication in many estuaries and coastal seas such as the Baltic Sea. The sedimented nutrients can affect bacterial communities which, in turn, are widely believed to contribute to release of nutrients such as phosphorus from the sediment. METHODS We investigated relationships between bacterial communities and chemical forms of phosphoru...

the mandovi estuary is highly influenced by mining and tourism related activities in the centralwest coast of india. vertical fluxes and accumulation of petroleum hydrocarbons (phcs) in three sedimentcores (d1, c1 and og) from the mandovi estuary were assessed using ultra-violet fluorescence (uvf)spectroscopy. the range of phcs values in estuarine sediments varied from 5.4 to 12.34 μg/g enrichm...

a r t i c l e i n f o The impact of dredging and dumping on the morphologic stability of the tidal channels is investigated using morphologic field observations for the Westerschelde estuary dating back to 1955. The results are used to verify the theoretical concept presented by Wang and Winterwerp (2001). This concept states that a critical threshold for the amount of sediment dumping exists a...

Coastal environments are nitrogen (N) removal hot spots, which regulate the amount of land-derived N reaching open sea. However, mixing between freshwater and seawater creates gradients inorganic bioavailable organic matter, affect cycling. In this study, we compare nitrate reduction processes estuary offshore archipelago in coastal Baltic Sea. Denitrification rates were similar both environmen...

Sequential extraction of Hg was performed in a core collected from intertidal area in Ulhas Estuary in order to characterize the downward distribution and diagenetic behavior of Hg in a polluted estuary. Concentration of total Hg ranged between 0.46 and 6.40 microg g(-1) with significant decrease in surficial sediment as a result of closing of two Hg-cell based chlor-alkali plants. Results of s...

Concentrations of Hg, total organic carbon (TOC), Al, Fe and Mn were determined in sediment of the Amba Estuary between the mouth and the head over a distance of 24 km in December and May during 1997-2002. Temporal and spatial changes in metal concentrations appear to be due to sediment movement associated with tidal movements. The Hg concentration varies in 0.05 -2.66 μg g range and the profil...