How the clear blue Med is washed up and dead

Dec 05, 2004

As millions of holidaymakers will testify, the Mediterranean is uniquely clear – and blue – unlike the cloudy grey of many coastal waters. But how many of its grateful bathers realise that the Med is so crystal clear because it’s the ocean equivalent of the Sahara desert?
A Leeds-led team of international scientists studying the fragile marine ecosystem of the Eastern Mediterranean has found that the reason the waters are so transparent is an acute shortage of phosphates – vital elements at the bottom of the marine food chain.

Currents through the Straits of Sicily are ‘washing’ nutrient-rich waters out of the Mediterranean, and bringing in fresh surface water which has no nutrients. Without these fertilisers, plankton cannot grow, depriving bacteria of the food they need to process the extra nitrates in the water, and release them into the atmosphere as nitrogen. Thus the seas of the Mediterranean have a build-up of nitrates – around twice as much, proportionately, as the other oceans of the world – but few plants and nutrients to cloud the water.

Leeds earth and biosphere institute director Professor Michael Krom said: “Many of the great ancient civilisations have developed on the shores of the Eastern Mediterranean, and more recently it has become home to millions of people and the holiday destination for millions more.”

“But despite all these people, the waters have remained clear deep blue, rather than the murky grey associated with highly populated areas whose waste products normally increase nutrient levels in the seas into which they flow.”

Professor Krom’s team, drawn from seven countries, has finally provided the link between the ‘blueness’ of the Mediterranean, and its high imbalance of phosphates and nitrates. “The oceans are the life support system of the planet, and so understanding the elements controlling plant growth in the oceans is a big deal,” said Professor Krom.

The research results will be fed into the Mediterranean forecasting system, which is developing the world’s first ‘weather forecast’ for ocean waters.

Source: University of Leeds

Explore further: NASA-NOAA Suomi NPP Satellite team ward off recent space debris threat

add to favorites email to friend print save as pdf

Related Stories

Comet Siding Spring whizzes past Mars

8 hours ago

A comet the size of a small mountain whizzed past Mars on Sunday, dazzling space enthusiasts with the once-in-a-million-years encounter.

Major breakthrough could help detoxify pollutants

13 hours ago

Scientists at The University of Manchester hope a major breakthrough could lead to more effective methods for detoxifying dangerous pollutants like PCBs and dioxins. The result is a culmination of 15 years of research and ...

Recommended for you

'Twisted rope' clue to dangerous solar storms

10 hours ago

A "twisted rope" of magnetically-charged energy precedes solar storms that have the potential to damage satellites and electricity grids, French scientists said on Wednesday.

User comments : 0