Navigation Links
Don't judge a brook by its color -- brown waters are more natural

Over the last 20 years lakes and streams in remote parts of the UK, southern Scandinavia and eastern North America have been increasingly stained brown by dissolved organic matter. In this weeks Nature journal (22 November) an international team, led by researchers from UCL (University College London) and the US Environmental Protection Agency (EPA), demonstrates that the colour change is indicative of a return to a more natural, pre-industrial state following a decline in the level of acid rain.

Don Monteith, Senior Research Fellow at the UCL Environmental Change Research Centre, says: A huge amount of carbon is stored in the form of organic deposits in soils, and particularly in the peatlands that surround many of our remote surface waters. In the past two decades an increasing amount of this carbon has been dissolving into our rivers and lakes, turning the water brown.

There have been numerous attempts to explain whats happening, with everything from global warming to changing land-use cited as the cause. Some studies have suggested that were seeing an unprecedented phenomenon as soils destabilise with unpredictable consequences for the global carbon cycle.

John Stoddard of the EPA says: By analysing water chemistry records from over 500 sites across the northern hemisphere weve found that the dominant factor in the whole process is not global warming. The most important driver has actually been the major reduction in acid rain since the 1970s. As acidity and pollutant concentrations in the soil fall, carbon becomes more soluble, which means more of it moves into our lakes and rivers and more can be exported to the oceans.

In some ways were seeing waters returning to their natural, pre-industrial state. However, more research is needed into the implications for freshwaters. The environmental pathways of heavy metals like aluminium and mercury, for example, are closely tied to dissolved organic carbon, and its too early to know how increasing organic matter will affect these toxic compounds.

Chris Evans, from the UK Centre for Ecology and Hydrology, adds: The suggestion that waters are returning to more natural conditions may be of little consolation to water supply companies as they are faced with the increasingly difficult - and expensive task of removing the colour from drinking water using treatment facilities that were designed to deal with the lower concentrations experienced in previous years.

Data for this study was drawn from nationally funded monitoring programs in the UK, USA, Canada, Norway, Sweden and Finland. Trends in dissolved organic carbon, air temperatures and a suite of other chemical variables were assessed using data from 1990-2004. The study is the largest of its kind and the data represents the main source of high quality, long-term information about the condition of our headwater systems. Ironically many of the study sites, including those in the UK, are under threat of imminent closure or scaling back due to cuts in government funding. This comes despite increasing recognition of the urgent need to monitor the response of natural environments to climate change and other man-made pressures, and the obvious value of these records for increasing our understanding of environmental processes.


Contact: Dave Weston
University College London

Related biology news :

1. Interaction of just 2 genes governs coloration patterns in mice
2. Scientists discover important beauty secret for balanced skin color and tone
3. Color contrast is seen by the brain early doors
4. A search for biomarkers for early detection of colorectal cancer
5. Interleukin-8, key marker for colorectal cancer treatment
6. Colorful view for first land animals
7. Curry-derived molecules might be too spicy for colorectal cancers
8. Good earth: Brown chemists show origin of soil-scented geosmin
9. Brown scientists take the petri dish to new dimensions
10. Innovative civil engineering application promises cleaner waters
11. Low oxygen in coastal waters impairs fish reproduction
Post Your Comments:
(Date:11/16/2015)... Calif. , Nov 16, 2015  Synaptics ... of human interface solutions, today announced expansion of ... TouchView ™ touch controller and display driver ... revolution of smartphones. These new TDDI products add ... TD4100 (HD resolution), TD4302 (WQHD resolution), and TD4322 ...
(Date:11/12/2015)... , Nov. 11, 2015   Growing ... reliable analytical tools has been paving the way ... qualitative determination of discrete analytes in clinical, agricultural, ... are being predominantly used in medical applications, however, ... environmental sectors due to continuous emphasis on improving ...
(Date:11/10/2015)... 2015 About signature verification ... to identify and verify the identity of an ... the secure and accurate method of authentication and ... individual because each individual,s signature is highly unique. ... dynamic signature of an individual is compared and ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... Nov. 24, 2015  Asia-Pacific (APAC) holds the ... (CRO) market. The trend of outsourcing to low-cost ... but higher volume share for the region in ... however, margins in the CRO industry will improve. ... ( ), finds that the market ...
(Date:11/24/2015)... Nov. 24, 2015 Halozyme Therapeutics, Inc. (NASDAQ: HALO ... New York on Wednesday, December 2 at ... , president and CEO, will provide a corporate overview. ... at 1:00 p.m. ET/10:00 a.m. PT . ... will provide a corporate overview. --> th Annual ...
(Date:11/24/2015)... ... November 24, 2015 , ... International Society ... one of the premier annual events for pharmaceutical manufacturing: 2015 Annual Meeting. The ... where ISPE hosted the largest number of attendees in more than a decade. ...
(Date:11/24/2015)... , November 24, 2015 ... market research report "Oligonucleotide Synthesis Market by Product & ... Gene Synthesis, Diagnostic, DNA, RNAi), End-User (Research, Pharmaceutical & ... by MarketsandMarkets, the market is expected to reach USD ... 2015, at a CAGR of 10.1% during the forecast ...
Breaking Biology Technology: