Effect of Danube River dam on Black Sea biogeochemistry and ecosystem structure

Article Abstract:

The damming of the Danube River contributed to the observed changes in Black Sea surface waters. This was gleaned from long-term data sets of water and nutrient discharge from the Danube to the Black Sea, which show a reduction in the river's dissolved silicate load by about two-thirds since dam constructions in the early 1970s. A consequent decline by over 60% in wintertime dissolved silicate concentrations was noted in central surface waters of the Black Sea. The ensuing changes in silicon to nitrogen ratio of the water's nutrient load seem to be greater than those triggered by eutrophication alone. These changes also appear to be behind the drastic shifts in phytoplankton species composition from siliceous to non-siliceous.

Environmental aspects, Danube River, Biotic communities, Biogeochemistry, Black Sea

---

Evolution of the nitrogen cycle and its influence on the biological sequestration of CO2 in the ocean

Article Abstract:

The evolution of biogeochemical cycles are examined to determine the factors that influence total oceanic primary productivity. For the past two million years, the rise in the transportation of organic carbon from surface waters into marine sediments were linked to the decline in atmospheric carbon dioxide concentrations. This indicates that fixed nitrogen is a variable that controls primary productivity on geological timescales.

Analysis, Oceanographic research, Nitrogen cycle

---

Similar abstracts:

• Abstracts: Effects of fire on golden eagle territory occupancy and reproductive success. Responses of American crow populations to campgrounds in remote native forest landscapes
• Abstracts: From angiogenesis to neuropathology. Accessing a transporter structure. Cell survival guide
• Abstracts: Therapeutic silencing of an endogenous gene by systemic administration of modified siRNAs. A cholesterol connection in RNAi
• Abstracts: Fresh angle on the polar seesaw. Grape ripening as a past climate indicator. The Atlantic heat conveyor slows
• Abstracts: First evidence of a venon delivery apparatus in extinct mammals. Pleistocene to Holocene extinction dynamics in giant deer and woolly mammoth

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.