Throughout history, people have thought of the ocean as a diverse and limitless source of food.In addition, they started using new fishing technologies that made fishing ordet These technologies included sonar to locate fish, and dragging large nets along the ocean floor.RISE OF THE LITTLE FISH

In 2010, the Census of Marine Life estimated that 90 percent of the big ocean fish populations are gone, mainly due to overfishing.A study published in 2006 in the journal Science made a prediction: If we continue to overfish the oceans, most of the fish that we catch now-from tuna to sardines-will disappear by 2050.Another way to improve the biodiversity of the oceans is to develop aquaculture-fish farming.In particular, commercial fishing has greatly reduced the number of large fish such as cod, tuna, and salmon.Sonar technology uses sound waves to locate objects on or under the surface of the water.One major factor is overfishing.