The total maximum daily load ~TMDL! concept provides the basis for regulating pollution load from riverine sources to impaired water bodies. However, load is comprised of two components: flow and concentration. These two components may have confounding, or even conflicting, effects on waterbody attributes of concern. This is particularly the case for dynamic, advective systems, such as estuarie...

Heavy metal contamination of soil and sediment in estuaries warrants study because a healthy estuarine environment, including healthy soil, is important in order to achieve ecological balance and good aquaculture production. The Ba Lat estuary of the Red River is the largest estuary in northern Vietnam and is employed in various land uses. However, the heavy metal contamination of its soil has ...

For a better understanding of the phosphorus dynamics and bioavailability in temperate climates, sequential chemical extraction techniques were used to study sediment P-pools distribution and relative importance in a eutrophicated estuary. Results indicate a shift in importance from the iron-bound P fraction to the CaCO3-bound P fraction with increasing salinity, which suggests a decrease in bi...

kol river drains into the persian gulf and its watershed encompasses  areas  in  hormozgan, kerman and fars provinces. identification of fish species of the river was conducted seasonally from summer to winter 2005. we selected 8 sampling stations based on the height of  sea  level  from branches of kol river near estuary. totally, 160 specimens were caught with gillnet, cast net and hook. we i...

The current study documents the fate of current-use pesticides in an agriculturally-dominated central California coastal estuary by focusing on the occurrence in water, sediment and tissue of resident aquatic organisms. Three fungicides (azoxystrobin, boscalid, and pyraclostrobin), one herbicide (propyzamide) and two organophosphate insecticides (chlorpyrifos and diazinon) were detected frequen...

The reduction of nutrient over-enrichment (eutrophication) is the most important undertaking in the restoration of the Chesapeake Bay ecosystem. Efforts toward this end are guided and evaluated though extensive use of linked simulation models of the airshed, watershed and estuary. These models track the inputs of nutrients through the watershed and into the bay and predict the consequences to w...

Population distribution of amphioxus (Branchiostoma belcheri tsingtauense) was investigated in the Luan River Estuary from 1999 to 2011, to describe its trends and discover the factors that influence its decline. Amphioxus are distributed on the seabed at 5-10 m depth, between the Xinkai Estuary and the Dapu River Estuary, where the primary sand components of the sediment are medium and fine, w...

Concentrations, spatial distribution and sources of 17 polycyclic aromatic hydrocarbons (PAHs) and methylnaphthalene were investigated in surface sediments of rivers and an estuary in Shanghai, China. Total PAH concentrations, excluding perylene, ranged from 107 to 1707 ng/g-dw. Sedimentary PAH concentrations of the Huangpu River were higher than those of the Yangtze Estuary. The concentration ...

The concentrations of seven trace metals (Fe, Mn, Cu, Cr, Co, Pb and Zn) in three sediment cores were analysed to assess the depositional trends of metals and their contamination level in the Mandovi estuary, west coast of India. All sediment cores showed enrichment of trace metals in the upper part of core sediments and decrease in concentration with depth, suggesting excess of anthropogenic l...

Monthly samples of sediment were collected from the Souss estuary, to determine the changes which have occurred in the concentrations of ten metals between 2001 when the low estuary was receiving the wastewaters from Agadir city and 2003 after stopping the sewage dumping. The annual contents of Cu, Fe, Zn (in 2001) and those of Cr, Cu, Fe, Mn, Ni, Pb, and Zn (in 2003) showed significant correla...