Diverse nature of the seasonally coastal eutrophication dominated by oceanic nutrients: An eco-system based analysis characterized by salmon migration and aquaculture.

Previously, studies of coastal eutrophication have usually focused on the nutrients input from adjacent land sectors, such as rivers, submarine-ground discharges, and atmospheric depositions. Here we report two examples of well-managed seasonal eutrophication phenomena in coastal marine environments, where nutrients come predominantly from offshore: one by humans and the other by nature (higher trophic animals). In the Sanggou Bay of North China, the total amount of incoming nutrients from the open Yellow Sea is taken up by seaweeds.

[Distribution, seasonal variation and influence factors of dissolved inorganic arsenic in the Sanggou Bay].

The biogeochemical behavior of arsenic in the aquatic environment has already captured the attentions of scientists due to its complex forms and toxicity. Four cruises were carried out in April, August, October 2011 and January 2012 in the Sanggou Bay. The concentrations of total dissolved inorganic arsenic (TDIAs, TDIAs = [ As(5+] + [As(3+)]) and arsenite (As(3+)) were measured by Hydride Generation-Atomic Fluorescence Spectrometry (HG-AFS).

[Phosphate adsorption characteristics onto surface sediments from aquaculture area in Sungo bay].

Phosphate adsorption characteristics onto surface sediments from aquaculture area in Sungo bay were studied in laboratory simulating condition, and phosphate adsorption-desorption equilibrium mass concentration was also analyzed. The results showed that the process of phosphate adsorption onto sediments mainly occurred within 0.5 h, and attended to dynamic equilibrium after 6 h.

[Forms and bioavailability of phosphorus in surface sediments from Sungo Bay].

Unlabelled: Forms and bioavailability of phosphorus in the sediments of eight sampling sites from Sungo Bay were analyzed by means of sequential extraction method (SEDEX).

Results: showed that: (1) The main form of total phosphorus (TP) in sediments was inorganic phosphorus (IP), which accounted for 73.33% and organic phosphorus (OP) was only the minor part.

[Diffusive fluxes of dissolved inorganic nitrogen across sediment-water interface in net-cage culture area of Tangdao Bay].

Abstract: On basis of field data measured during 4 cruises from August 2004 to May 2005, concentrations of NH4+ -N, NO3- -N, NO2- -N in overlying and interstitial waters of sediments in net-cage culture areas of Tangdao Bay were analyzed. Moreover, diffusive fluxes of dissolved inorganic nitrogen from sediments were estimated by Fick's first law. Results showed that the main form of inorganic nitrogen in overlying and interstitial waters of sediments was NO3- -N, accounting for 73.