8. The Continental Shelf

In the next two chapters, we will take a tour aboard an imaginary hover car to visit the world’s continental shelves and the deep ocean. The continental shelf (as the name suggests) is the submerged part of the continents, and the features we see underwater are comparable to those we see today along the coast. The continental shelf is where rivers disgorge their loads of sediment and where glaciers built moraines during the ice age, providing the material needed to make sandbanks. Sand is in fact the second most used commodity on Earth after freshwater. It is a key ingredient of concrete and is also used to replenish beaches that are eroding because of rising sea level. In this chapter we will observe the impacts of bottom trawl fishing on seabed habitats and consider the need for marine parks. We will explore hidden coral reefs in the Gulf of Carpentaria and see how bleaching of corals is happening more and more often. Has a tipping point been passed? Will we be able to save the coral reefs? To avoid burning fossil fuels, we should look at harnessing the ocean’s tide power as a renewable power source. Human impacts on land often reach the ocean. The Ok Tedi gold mine disaster in the Fly River, Papua New Guinea, is an example of this.