Oceans are world's seventh largest economy worth $24tn, says WWF report

Vast economic worth of world's oceans includes fishing, tourism and shipping but is declining due to pollution, climate change and overfishing

The monetary value of the world's oceans has been estimated at US$24tn in a new report that warns that overfishing, pollution and climate change are putting an unprecedented strain upon marine ecosystems.

The report, commissioned by WWF, states the asset value of oceans is $24tn and values the annual "goods and services" it provides, such as food, at $2.5tn.

Half of the world's corals and nearly a third of its seagrasses have disappeared