At a meeting in Paris last month, the General Assembly of UNESCO’s Intergovernmental Oceanographic Commission (IOC) agreed to introduce a new thermodynamic description of seawater. The new description will be based on a new salinity variable called Absolute Salinity.

“Scientists will now have an accurate measure of the heat content of seawater for inclusion in ocean models and climate projections,” said Hobart-based CSIRO Wealth from Oceans Flagship scientist Dr Trevor McDougall. “Variations in salinity and heat influence ocean currents and measuring those variations are central to quantifying the ocean’s role in climate change. The new values for salinity, density and heat content should be in widespread use within 18 months.”

Salinity is measured using the conductivity of seawater, a technique which assumes that the composition of salt in seawater is the same all over the world – which it isn’t. Salinity varies throughout the world’s oceans and for over one and a half century, scientists have been searching for the ‘magic formula’ for measuring salinity.

“The new approach, involving Absolute Salinity, takes into account the changes in the composition of seasalt between different ocean basins which, while small, are a factor of about 10 larger than the accuracy with which scientists can measure salinity at sea,” Dr McDougall explained.

In an effort to end the country’s reliance on imported uranium, Dr Masao Tanada of the Japan Atomic Energy Agency has developed a fabric capable of absorbing uranium directly from seawater.

“At the moment, Japan has to rely on imports of uranium from Canada and Australia, but this technology could be commercially deployed in as little as five years,” says Tanada.

In Canada and Australia, the uranium is extracted in conventional mining operations which are expensive and damaging to the environment.

Dr Tanada is now hoping to secure funding to set up a 400 square mile underwater “uranium farm” consisting of anchored sponges made from the new material; a fabric composed primarily of irradiated polyethylene.

The world’s oceans contain an estimated 4.5 billion tons of uranium; roughly 3.3 parts per billion. Japan uses 8,000 tons of uranium per annum; an amount that Dr Tanada says could be harvested from the Kuroshio Current that flows along Japan’s eastern seaboard. His proposed 400 square mile farm would on its own supply Japan with roughly one-sixth of what it needs to run its nuclear power stations.