The science-based management and governance of shared transboundary water systems is the focus of a wide-ranging collection of articles now published in a special edition of the Elsevier journal Environmental Development.

A collaboration of the Global Environmental Facility's IW:LEARN project and the UN University's Canadian-based Institute for Water, Environment and Health, the special open-access volume includes a treasury of articles available with open public access until the end of 2014.

The volume builds on a 2012 study of the use of science in roughly 200 GEF-supported transboundary water projects involving public investments of more than US$7 billion over 20 years. GEF partnered with UNU and the UN Environment Programme to extract lessons from that huge project portfolio. The volume is highlighted by papers detailing innovations in science-based management and scientific research authored by past or present projects from the portfolio.

"This assembly of articles underlines the overarching lesson that science must play a central role in decisions and investments involving trans-boundary water issues," says Zafar Adeel, director of UNU's Canadian-based International Network on Water, Environment and Health (UNU-INWEH).

"At the heart of this are concerns of cardinal importance: food and energy security, adaptation to climate variability and change, economic growth and human security."

Transnational water management in the Arab region
Arab regional governments need to adopt the holistic, ecosystem-based Integrated Water Resources Management (IWRM) policies, say experts Ahmed Abou Elseoud, Secretary General of the Egyptian Environmental Affairs Agency (EEAA), State Ministry of Environment, and UNDP Advisor Mary M. Matthews. They warn that:

+ The threat of water scarcity is being exacerbated by climate change and a growing population;

+ Water projects are severely underfunded, complicating efforts to implement more sustainable water management policies; and

+ Water management responsibilities are decentralized and face difficulties in coordination.

Global warming changing the North Atlantic fisheries
Scientists forecast important changes to fish stocks in North Atlantic marine ecosystems where surface temperatures are trending higher in, for example, the North Sea but lower in the Humboldt Current. These changes are a critical consideration in the development of ecosystem approaches to fisheries management.

Data show the largest temperature change underway in the North Sea, where waters were 1.38+ C warmer in 2009 compared with 1982. By comparison, waters in the Iceland Shelf are 1.02+ C warmer, the Gulf of Mexico waters are 0.27+ C warmer and the U.S. Southeast Shelf waters are 0.05+ C warmer.

There is a downward trend in fish yields in the North Sea, Celtic-Biscay Shelf and Iberian Coastal ecosystems, attributed to reduced zooplankton production, increased water column stratification, and reduced seasonal nutrient mixing in the upper water layers.

Coastal condition, Gulf of Mexico
Authors Gracia-Rios et al. offer a case study to estimate the coastal condition in the Gulf of Mexico, including habitat degradation, water quality, sediment quality, fish, and benthic fauna. Different parameters were measured for each module and categorized as being "good" (score of 5), "fair" (score of 3) or "poor" (score of 1). The Coastal Condition Index was calculated as the mean of the scores for all modules.

Governance challenges, Nile River Basin
Authors Paisley and Henshaw discuss the multiplicity of governance challenges in the transboundary Nile River Basin (extends through 11 countries) and propose enactment of a comprehensive international program of cooperation. Otherwise, the 300 million people who depend on the Nile will be confronted with even more profound challenges now and in the future.

Managing shared aquifers
Author Kettelhut outlines the lessons learned from the Guarani Aquifer, including the need to prioritize efforts especially in areas located at or near boundaries of countries. Priorities can be profound challenges because of information and knowledge gaps. The best way forward is for participating countries to address and implement actions as collaborators -- an objective much easier stated than accomplished.

"Dynamic management" of large marine ecosystems
Authors Vousden and Stapley explore the innovative Science-Based Governance approach increasingly employed in the Agulhas and Somali Current large marine ecosystem. A "Dynamic Management Strategy" incorporating "weight-of-evidence" decision-making is part of the approach designed to fast track processes, improve early warnings and make adaptive management feasible.

Research carried out outside of the GEF IW portfolio is also presented in the volume as a way to highlight ongoing and new research that can be used by those engaged in transboundary waters research and management all around the world.

Highlights among those articles:
Northward creep of "world's worst water weed" foreseen

UNEP-based authors point up a new climate change-related dread: higher temperatures are expected to extend the expensive reach of the tropical, fast-growing water hyacinth -- dubbed "the world's worst water weed" -- to water bodies at higher latitudes, posing new threats to aquatic biodiversity, national economies and human health.

Scientists call for intensified monitoring, mitigation and management measures to keep the weed in check.

Native to the Amazon basin and originally popular as a pond ornament due to its large purple flowers, water hyacinth now plagues 50 countries in Africa, Asia, North America and Europe -- ranked by the International Union for Conservation of Nature among the planet's 100 most aggressive invasive species, a weed known to as much as double in population in just two weeks.

The large floating mats choke off sub-surface species such as fish and turtles from light and oxygen and support organisms harmful to human health.

Annual economic impacts in seven African countries alone have been estimated at between US $20 million and $50 million; Africa-wide, costs are thought to reach US $100 million. In Mexico, more than 40,000 hectares of reservoirs, lakes, canals and drains are infested. In China, the annual costs of water hyacinth management are estimated at around $1.3 billion, and in the US its economic harm is estimated at $120 billion. In California, the weed has severely impacted the Sacramento-San Joaquin River Delta.

Taking off: the use of flying robot drones on environmental missions
Tracking the spread of floods and other natural disasters, chasing wildlife poachers, mapping deforestation, detecting illegal mining or logging, and sniffing out volcanic threats are among the growing uses environmental scientists are making of unmanned flying robot drones.

According to UNEP, "eco-drones" offer a relatively low-cost way to collect atmospheric data, for example, or real time, high resolution images offering information unobtainable from satellites and ground surveys.

Notable early applications:
Authorities in Sao Paulo, Brazil, have deployed 14 drones (cost: US $350 million) to monitor deforestation in the Amazon, track poachers and detect illegal mining. And in 2012 the World Wildlife Fund received US $5 million from Google to deploy drones and other technologies to track animal poachers in Africa.

The US National Aeronautics and Space Administration (NASA) flew a drone into the plume over Costa Rica's Turrialba Volcano to collect data about its temperature, ash height and gas concentration (such as sulphur dioxide) -- information that can help scientists determine the direction of a volcanic plume and alert populations downwind. Conventional aircraft are unable to collect such data because ash would clog the engines.

The use of drones to detect forest fires has been tested by several US agencies, enabling earlier public alerts and better firefighting plans. An 11-meter (33 foot) drone with a 20 meter (60 foot) wingspan and more than 180 kg (360 pounds) of sensors has been used by the United States Department of Agriculture (USDA) and NASA to gather fire-fighting information in California. Named Ikhana, it is designed for long ?ights at a typical altitude of 12 km -- high enough to stay above the fires' heat.

Rapid urbanisation and road construction in China have led to more frequency, and more intense, landslides along roads. Using high resolution cameras, drones monitor vulnerable highways, detecting telltale cracks and changes in stress to offer early landslide warnings.