Posted on behalf of Michele Catanzaro.

China's Yangtze River has taken on a russet hue.{credit}ChinaFotoPress via Getty Images{/credit}

A stretch of China’s mighty Yangtze River, near the city of Chongqing, has turned an alarming shade of red (International Business Times).

The cause of the colouring is still unclear. “One possible cause of the colouration may be suspended sediments, following heavy rains upstream”, says Hans Paerl, a marine and environmental scientist at the University of North Carolina in Chapel Hill. “This is common in large river systems such as the Yangtze, and southern China has had large rainfall events this summer,” he says.

Indeed, on 7 September the Chongqing Environmental Protection Agency noted on its website that a water-quality monitoring centre on the Yangtze had detected very high concentrations of silt in the river. The agency says that torrential rain in the upper Sichuan province caused huge amounts of silt to wash into the Yangtze. It also says that the water does not contain hazardous or noxious substances.

Scientists interviewed by Nature say that it is unlikely, although not impossible, that the colouring is a result of an algal bloom. Sudden growths of algae, fed by fertilizer run-off (a process known as eutrophication), can sometimes produce blooms of brownish diatom algae in rivers, says Sergi Sabater, a limnologist at the Catalan Institute of Water Research in Spain, who carries out research in river ecology. Such ‘red tides’ of algae are sometimes observed in warm, shallow and nutrient-rich seas. But in this case, “if it is a eutrophication event, then it is enormous”, says John Dearing, a physical geographer at the University of Southampton, UK, who has done research into the eutrophication of lakes on the lower Yangtze.

Dearing also notes that in December 2011, the Jian River in northern China turned red after dye pollution leaked into the river from a factory. “Cases of dye pollution are very, very common in China,” he says.

The 1.8-million-square-kilometre Yangtze basin constitutes 18.8% of China’s land area and accounts for 36.5% of China’s available fresh water, according to the ChangJiang Water Resources Commission (CWRC), the river basin authority.

According to a 2007 WWF report, it is among the world’s top ten rivers at risk of serious pollution. In May 2011, China’s state council admitted that the river ecosystem could potentially be harmed by the Three Gorges Dam, located in the Hubei province, downstream of Chongqing (New York Times).

This post was corrected on 12 September. The original version erroneously identified John Dearing as a limnologist.

Posted on behalf of Brendan Borrell in Jeju, South Korea

Community-based conservation in Papua, Indonesia.{credit}Brendan Borrell{/credit}

Community-based conservation is poised to take a starring role in the effort to meet global biodiversity targets. That’s one of the take-home messages of the first-ever Protected Planet Report, released on Friday 7 September by the United Nations Environment Programme World Conservation Monitoring Center (UNEP-WCMC).

The semi-annual report will track progress towards the 2020 Aichi Biodiversity Targets to protect 17% of the area in each of 823 terrestrial ecoregions, and 10% of the area in 232 marine ecoregions (see ‘World gets 2020 vision for conservation’ ). Although the new analysis concludes that the overall size of the protected area network has been approaching that scale, species living there are still not getting enough protection: only one-third of terrestrial ecoregions, and 13% of marine regions, pass muster, the report says.

But the report, unveiled at the IUCN World Conservation Congress, held from 6-15 September in Jeju, South Korea, also reveals a profound shift in the way protected areas are being managed around the world. In 1990, just 14% of protected areas allowed hunting and other sustainable uses of natural resources, but today that number has risen to 32%. At the same time, the amount of area managed exclusively by governments has declined from 96% to 77%, a trend reflecting the rise of community-based conservation and co-management schemes with indigenous peoples. “The protected area network is rapidly changing not only in its area, but in the different approaches to management,” says the report’s lead author, geographer Bastian Bertzky.

In fact, Bertzky says that indigenous reserves and sacred natural sites may be the key that enables countries to meet Aichi targets on such a short timeline. Only a fraction of such sites meet the requirements of the World Database on Protected Areas, which was used to compile the report, but they would still qualify under the terms of the Convention on Biological Diversity. His colleagues at UNEP-WCMC recently launched the Indigenous and Community Conserved Areas database, and these areas could double estimates of the amount of the land under some form of protection. “We still need to figure out how to include these areas in our global analysis,” he says.

Posted on behalf of K. S. Jayaraman.

Indian meteorologists are under fire for having predicted a normal monsoon when the country is heading for a drought (see the Hindu).

The rains during the 4-month-long monsoon season (June to September) — accounting for more than 80% of India’s annual rainfall — are crucial for the agricultural economy. In April, the Indian Meteorological Department (IMD) predicted that the monsoon season would see normal or above-average rainfall. On 2 August, however, it confessed that more than half of India has received “deficient or scanty” rains, and that the monsoon rainfall for the entire country is likely to be 19.7% lower than normal.

“I admit this year we are going to go wrong!” Bhupendra Nath Goswami, director of Pune-based Indian Institute of Tropical Meteorology (IITM), whose seasonal prediction system was used by the IMD to make the forecast, tells Nature. “But blaming the meteorologists is not going to solve the problem,” he says. “You have to understand that regional climate like the monsoon has a potential limit on predictability due to the chaotic nature of the weather and climate system. Right now our models have skills significantly below this limit.”

Jayaraman Srinivasan, chairman of Divecha Centre of Climate Change at the Indian Institute of Science in Bangalore, agrees. “No forecasting centre in the world (American, European, Japanese or Indian) has been able to forecast monsoon rainfall accurately this year or in the past,” he says. “Hence the question to ask is, ‘what should scientists around the world do to improve the seasonal forecast of the monsoon rainfall?’” A similar question was posed in 2002, when the rainfall in July was 50% below normal (see ‘Climate model under fire as rains fail India’).

Srinivasan says that the accuracy of the forecast is hampered by uncertainties in conditions such as wind velocity, cloudiness and humidity. Gathering more data, using radars, for example, could reduce the errors, “but this will only improve the short-term forecast of less than one week”, he says. “The seasonal forecast will improve only if there is a dramatic improvement in our understanding of how clouds are born, grow and decay.”

New information about cloud processes provided by NASA’s TRMM (Tropical Rainfall Measuring Mission) and CLOUDSAT satellites has not yet “translated to tangible benefits for seasonal forecasting”, he says.

India’s Ministry of Earth Sciences recently launched a ‘Monsoon Mission’ to improve the prediction of Indian summer monsoon rainfall, says Goswami. The 5-year, US$75-million project aims to bring together researchers from “all relevant organizations and research institutes” and give them the best computational facilities to improve their meteorological models.

“Accurate prediction of monsoon rainfall may be as tough as finding the Higgs boson,” says Srinivasan, “and hence it will demand a large financial and human resource.”