A small marine biosphere in the Proterozoic
| Autor: | Thomas A. Laakso, Daniel P. Schrag |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Aquatic Organisms
010504 meteorology & atmospheric sciences Earth science chemistry.chemical_element 010502 geochemistry & geophysics Photosynthesis 01 natural sciences Nutrient Water column Rivers Seawater Organic matter Ecology Evolution Behavior and Systematics 0105 earth and related environmental sciences General Environmental Science chemistry.chemical_classification Proterozoic Phosphorus Biosphere Primary production Biota Oxygen chemistry General Earth and Planetary Sciences Environmental science Estuaries |
| Zdroj: | Geobiology. 17:161-171 |
| ISSN: | 1472-4669 1472-4677 |
| Popis: | The riverine supply of the globally limiting nutrient, phosphorus, to the ocean accounts for only a few percent of nutrient supply to photosynthetic organisms in surface waters. Recycling of marine organic matter by heterotrophic organisms provides almost all of the phosphorus that drives net primary production in the modern ocean. In the low-oxygen environments of the Proterozoic, the lack of free oxygen would have limited rates of oxic respiration, slowing the recycling of nutrients and thus limiting global rates of photosynthesis. A series of steady-state mass balance calculations suggest that the rate of net primary production in the ocean was no more than 10% of its modern value during the Proterozoic eon, and possibly less than 1%. The supply of nutrients in such a world would be dominated by river input, rather than recycling within the water column, leading to a small marine biosphere found primarily within estuarine environments. |
| Databáze: | OpenAIRE |
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