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The natural world. Looking pretty for 3.5b years.

Ecology Lesson, 2

Ecology Lesson, 2

Author: Hugh Bollinger/Monday, August 20, 2018/Categories: natural history, space science, marine life, sustainability, environment, climate change

       Yukon River Delta, Sediment Runoff, and Phytoplankton Bloom, September 2002 (credit: NASA & USGS)

The ecology of land and sea are directly connected by rivers feeding deltas. Sediments moving down a river eventurally end up in a bay, estuary, or the ocean. The flows of the Nile, Yangtze, and Mississippi rivers have told much about history, civilization, and ecology for millennia.

Polar rivers in the Arctic are especially helpful to observe climate change in 'real time'. Landscape-wide soils, long frozen as permafrost, are now melting and the runoff deposited directly into the Arctic Ocean. A recent study measured changes to the Yukon River over more than 30 years using water chemistry data as a timeline guide. According to the report:

"the Yukon region has experienced a warming climate over the last century that has altered air temperature, precipitation, and permafrost. Using a water chemistry database from 1982-2014 for the Yukon River and its major tributary, the Tanana River significant increases of dissolved calcium (Ca), magnesium (Mg), and sodium (Na) were found in both rivers. Additionally, sulfates (SO4) and phosphorus (P) increased in the Yukon River.

The authors of the study concluded: "the thawing permafrost enables the release of more greenhouse gases to the atmosphere and also allows much more mineral-laden and nutrient-rich water to be transported to rivers, groundwater, and eventually into the Arctic Ocean.” 

Nutrients such as calcium, magnesium, and phosphorus are essential for plant growth and when abundant in oceans can allow for the the spread of phytoplankton blooms. A video on permafrost shows the consequences of melting frozen-ground has on cities, landscapes, and regional ecology.

Unlike the Nile, Yangtze, or Mississippi rivers the changes currently happening to the Arctic Ocean's ecology are just beginning to be quantified and appreciated.



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