Dredging from oceans rings alarm bells

The United Nations Environment Programme (UNEP), in its report on dredging from oceans and seas, said that six billion tonnes of sediment are extracted annually, and this is causing huge harm to marine biodiversity, including the micro-organisms. “The scale of environmental impacts of shallow sea mining activities and dredging is alarming,” said Pascal Peduzzi, who heads the UNEP’s analytic centre GRID-Geneva. The enormous dredging activity causes turbidity of water, and noise effects on marine animals.

The UNEP had launched a global data platform on sediment extraction in marine environments, Marine Sand Watch, and uses artificial intelligence to track dredging of sand, clay, silt, gravel and rock from the seas. The hot spots of excessive dredging are the North Sea, South-east Asia and the East Coast of the United States.

There are no laws in most countries to regulate dredging activity. Indonesia, Thailand, Malaysia, Vietnam and Cambodia have banned marine sand export in the last 20 years. According to sand industry expert at GRID-Geneva, Arnaud Vander Velpen, China is the leader with the largest dredging fleet, followed by the Netherlands, the US and Belgium. It is estimated that the world construction used 50 billion tonnes of sand. Of this, four to eight billion tonnes come from the seas. The seas and oceans receive 10 to 16 billion tonnes of sediment. It is feared that the extraction rate will soon outpace the replenishment rate. Peduzzi pointed out that sand protects coastal communities from rising sea levels.

It is these small and apparently inconspicuous activities like dredging that carry a huge environmental price because the scale on which it is carried is stupendous. And the impacts match the scale of dredging. There is a compelling need to monitor all human activities and quantify them as has been done by GRID-Geneva for countries and people to realise the costs in terms of the environment. This should make people, especially the governments and the construction experts, find alternative ways of raising buildings. It may be necessary to go back to the traditional modes of homes made from local materials instead of the reinforced concrete structures that have come into vogue since the industrial revolution of the late 18th and early 19th century Europe, and the trend has spread to the rest of the world. There has been the growing danger of sand mining from the river beds and in places like India what has come to be known as the sand mafias cause havoc. There is as yet no study of the harm done to the river systems because of the sand mining. It looks like the ecological vigil is the need in all the countries and in all matters. It has been the case that the big issues like deforestation, pollution levels have caught the attention of the environmentalists and the smaller activities like sand mining or dredging in rivers, seas and oceans have escaped notice.

The concept of environment has now to be expanded to include the many big and small things because each human activity dents the environment, and given the large global population of eight billion people, each activity gets multiplied by so many times. And perhaps this cannot always be done at the global level through agencies like UNEP and the organisations working within it like GRID-Geneva.

The ecological monitoring has to be done at the local level and by many groups than are existent now. Like the local bird-watchers society, there has to be a local ecological society with many branches looking at the smaller activities that societies carry through unthinkingly, but which have serious environmental consequences. Environment has to become part of our daily lives and daily activities.