Environmental change in Jiaozhou Bay recorded by nutrient components in sediments
2010
Liu, Su Mei(Ocean Univ China, Coll Chem & Chem Engn, Minist Educ, Key Lab Marine Chem Theory & Technol, Qingdao 266100, Peoples R China) | Zhu, Bing De(Ocean Univ China, Coll Chem & Chem Engn, Minist Educ, Key Lab Marine Chem Theory & Technol, Qingdao 266100, Peoples R China) | Zhang, Jing(E China Normal Univ, State Key Lab Estuarine & Coastal Res, Shanghai 200062, Peoples R China) | Wu, Ying(E China Normal Univ, State Key Lab Estuarine & Coastal Res, Shanghai 200062, Peoples R China) | Liu, Guang Shan | 刘广山 | Deng, Bing(E China Normal Univ, State Key Lab Estuarine & Coastal Res, Shanghai 200062, Peoples R China) | Zhao, Mei-Xun(Ocean Univ China, Coll Chem & Chem Engn, Minist Educ, Key Lab Marine Chem Theory & Technol, Qingdao 266100, Peoples R China) | Liu, Guan Qun(Ocean Univ China, Coll Environm Sci & Engn, Qingdao 266100, Peoples R China) | Du, Jin Zhou(E China Normal Univ, State Key Lab Estuarine & Coastal Res, Shanghai 200062, Peoples R China) | Ren, Jing Ling(Ocean Univ China, Coll Chem & Chem Engn, Minist Educ, Key Lab Marine Chem Theory & Technol, Qingdao 266100, Peoples R China) | Zhang, Gui Ling(Ocean Univ China, Coll Chem & Chem Engn, Minist Educ, Key Lab Marine Chem Theory & Technol, Qingdao 266100, Peoples R China)
Inorganic or bulk organic chemical indicators, including organic carbon (OC), total nitrogen, organic nitrogen (ON), fixed ammonium (N-fix), exchangeable ammonium, exchangeable nitrate, organic phosphorus (OP), inorganic phosphorus (IP), and biogenic silica (BSi), were examined in a 3-m core collected in Jiaozhou Bay (JZB) to decipher how the environment has changed during the preceding two centuries of increasing anthropogenic influence in this region. Concentrations of BSi, OC, and OP reveal overall increases to ca.30 cm (similar to 1984), then decreased toward the surface, probably reflecting a decrease in the productivity of overlying waters since 1984. Aquaculture might play an important role in the decrease of nutrient elements in the upper layers recorded in sediments. The decreased molar BSi/OC ratios upcore may be due to a change in dominance from large- to small-sized diatoms, as shown in other research. However, the shift may also be related to changes from heavily-silicified to lightly-silicified diatoms or to non-siliceous forms such as dinoflagellates. ON concentrations increased towards the surface sediment, which is most likely consistent with the increase in fertilizer application and wastewater discharge. Concentrations of IP, total P. and Nfix all decreased conspicuously upcore at 41 cm depth (similar to 1977), and were largely consistent with the decrease in rainfall and freshwater discharge to JZB. Our data suggest that the environment has significantly changed since the 1980s. Anthropogenic activities in the watersheds may exert a substantial influence on carbon cycling processes in estuaries and potentially the coastal ocean. (C) 2010 Elsevier Ltd. All rights reserved.
Mostrar más [+] Menos [-]Palabras clave de AGROVOC
Información bibliográfica
Este registro bibliográfico ha sido proporcionado por AVANO