Seasonal Variations in Carbon and Nitrogen Constituents in Eelgrass (Zostera marina L.) as Influenced by Increased Temperature and Water-Column Nitrate

2002 ◽  
Vol 45 (1) ◽  
Author(s):  
B. W. Touchette ◽  
J. M. Burkholder
2013 ◽  
Vol 185 (8) ◽  
pp. 6831-6846 ◽  
Author(s):  
Masumi Koriyama ◽  
Yuichi Hayami ◽  
Akane Koga ◽  
Koichi Yamamoto ◽  
Alim Isnasetyo ◽  
...  

Author(s):  
Xuan Lu ◽  
Fengxia Zhou ◽  
Fajin Chen ◽  
Qibin Lao ◽  
Qingmei Zhu ◽  
...  

Elemental (total organic carbon (TOC) and total nitrogen (TN)) and stable carbon and nitrogen isotope compositions (δ13C and δ15N, respectively) in the surface sediment of Zhanjiang Bay (ZJB) in spring and summer were measured to study the spatial and seasonal changes of organic matter (OM) and assess the human-induced and environment-induced changes in the area. The OM in the surface sediment of ZJB was a mixture of terrestrial and marine sources, and was dominated by marine OM (54.9% ± 15.2%). Compared to the central ZJB, the channel and coastal ZJB areas had higher δ13C and δ15N values, higher TOC and TN concentrations, and lower TOC/TN ratios, indicating higher primary productivity and higher percentages of marine OM in the latter two subregions. Mariculture activities, sewage inputs, and dredging were responsible for these phenomena. Clear seasonal variations in OM were observed in ZJB. The average proportions of terrestrial OM in summer increased by 10.2% in the ZJB channel and 26.0% in the coastal ZJB area compared with those in spring. Heavy rainfall brought a large amount of terrestrial OM into the channel and coastal ZJB areas, leading to the increase of the terrestrial OM fraction in these two subregions in summer. In summary, anthropogenic influences had a significant influence on the spatial and seasonal variations of sedimentary OM in ZJB.


1969 ◽  
Vol 20 (1) ◽  
pp. 55 ◽  
Author(s):  
GF Humphrey ◽  
JD Kerr

The mean concentrations for all samples analysed were 0.17 �g/l for chlorophyll a and 0.22 �g/I. for chlorophyll c; there were 27 mg/m² of a and 35 mg/m² of c in the water column to 150 m. June-August gave the highest values. The model depth at which concentrations were greatest was 75 m. Diagrams of regression surfaces fitted to the results are given. Regression analysis showed that depth, latitude, and season affected the concentration of chlorophylls; latitude and season affected the column amount of chlorophylls.


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