Ocean ‘deserts’ are expanding

The least biologically productive areas of the oceans are expanding much faster than predicted, according to a new study by US researchers.

This change in ocean biology, linked to the warming of sea surface waters, may negatively affect the populations of many fish species trying to survive in these desert-like environments.

Between 1998 and 2007, these expanses of saltwater with low surface plant life in the Pacific and Atlantic Oceans grew by 15 per cent or 6.6 million square kilometers, according to researchers at the US National Oceanic and Atmospheric Administration (NOAA) and the University of Hawaii, writing in the in Geophysical Research Letters.

The expansion is occurring at the same time that sea surface temperatures are warming about one per cent or .02 to .04 degrees Celsius a year. The warming increases stratification of the ocean waters, preventing deep ocean nutrients from rising to the surface and creating plantlife.

These barren areas are found in roughly 20 per cent of the world