Watching 
Google Earth over time could show the effects of predator removal, such as through fishing, nearly anywhere on Earth, according to a study published this week in Scientific Reports.
A Google Earth image survey of the lagoon habitat at Heron Island within Australia’s Great Barrier Reef revealed distinct halo patterns within algal beds surrounding patch reefs. Underwater surveys confirmed that, as predicted, algal canopy height increases with distance from reef edges. This was due to herbivore grazing. In conjunction with behaviour studies, this shows that the actions the herbivores collectively took to avoid predators could be seen from space. Watching this over time provides and amazingly low cost way of monitoring the effects of predators. And indeed of the herbivores. Read the full article