Under the sea, breadcrumb trails are leading scientists to a new understanding of how ecotourism can affect marine ecosystems.<\/p>\n
Tourism operators around the world commonly bait snorkeling and diving sites with morsels of bread to entice fish\u2014improving tourists\u2019 experiences and the operators\u2019 bottom lines. According to a new study conducted in the Cook Islands, however, the tactic is actually changing fish behavior<\/a>.<\/p>\n At two coral reefs popular among snorkelers, researchers studied which fishes were swimming about before, during, and after they crumbled a loaf of bread over the water. After the feeding, they found that there were more fish overall, but from fewer species. Only a quarter of the fishes\u2014mostly carnivorous and omnivorous species\u2014actually ate the bread.<\/p>\n Sowing the reef, however, hurt smaller herbivorous fishes. The surge in activity caused \u201call this turmoil in their environment,\u201d says Natalie Prinz, a doctoral candidate at the University of Waikato in New Zealand and the study\u2019s lead author.<\/p>\n The bread prompted a feeding frenzy that temporarily created what ecologists call a \u201clandscape of fear.\u201d Since the fishes that were interested in the food tended to be predatory, it scared away smaller herbivorous fishes that didn\u2019t want to become targets once the bread was gone. The bread-induced landscape of fear also disrupted the natural foraging of specialized feeders, such as sturgeon, a species key to maintaining reef health, which is deterred in crowded environments.<\/p>\n The researchers think baiting could also be having other long-term effects on the reef. Giving fish food from outside their natural diet could change the composition and distribution of their excrement, which may negatively affect the growth of coral on the seafloor.<\/p>\n On coral reefs, \u201ceverything relies on everything else,\u201d says Danielle Dixson, a marine scientist at the University of Delaware who was not involved in the research. \u201cTiny changes can have huge implications.\u201d<\/p>\n