Publication Date:
2021-05-19
Description:
This study was conducted to determine phosphorous and nitrogen species at the surface sediment in the southern
Caspian Sea (Mazandaran Coast, Kelarabad). Surface sediments samples were collected at three stations from
autumn of 2011 to winter of 2012. All samples were perpared by digesting and extracting processes and then
phosphorous and nitrogen species concentrations determined using spectroscopy instrument. Results of this
study showed that annual mean of Loosely-P, Fe-P, Al-P, Bioava.-P, Ca-P, TIP, Rese.-P and TP was obtained as
5.06±0.33, 55.11±2.52, 42.38±3.74, 102.52±5.68, 172.91±7.12, 275±9.12, 333.30±28.52 and 608±52 µg/g.dw,
respectively. The results also showed that inorganic phophotous was less than organic phophorous during
different seasons, however, mean percentage of residue-P containing organic compounds and non-degredable
compounds was more than 50 percent. Percentage of Ca-P was higher than 60, whereas Bioava.-P was less than
40 percent. In addition, Fe-P and Loosely-P attained the maximum and minimum values, respectively, among
the bioavailable phophorous. The order of different forms of phosphorous were recorded as Org-P〉Ca-P〉FeP〉Al-P〉Loosely-P.
Annual mean of NH4/N, NO2/N, NO3/N, TIN, TON and TN were observed as 4.23±0.50,
0.06±0.01, 0.74±0.12, 5.02±0.53, 2.48±0.63 and 7.53±0.51 µg/g.dw, respectively. Annual percentage of TIN
was two folds than TON and concentration of NH4/N was also four times than NO3/N. As a conclusion, the
results revealed that main causes of Bioava.-P adsorbtion and desorbtion were temperature, Eh and pH. Also, the
form of NH4+
/N was of a high percntage because of anaerobic condition in the sediments. According to the high
ratios of nitrogen/phosphorous of sediments to nitrogen and phosphorous of bottow water, it finds that released
of those from the sediments to water will be happned with high rates. Therefore, it is expected that the
establishment of fish farming cages should be carried out with more precautionary approaches which not leads to
increased algae bloom.
Description:
Iranian Fisheries Science Research Institute
Description:
Published
Keywords:
Phophorous
;
Nitrogen
;
Surface sediment
;
Determination
;
Breeding
Repository Name:
AquaDocs
Type:
Report
,
Refereed
Format:
42pp.
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