New Study Shows Herbivorous Fish are Cereal Eaters

Reefs throughout the world are quickly becoming endangered with threats such as the crown of thorns, and in this case, algae that can proliferate too quickly suffocating other inhabitants such as coral. The threat of algae proliferation is becoming more and more of a factor as fishing all around the world has increased dramatically over the past 20 years and the removal of herbivorous fish that can naturally regulate algae growth is allowing some species of algae to grow out of control. Using underwater filming techniques researchers from Georgia Tech have discovered some herbivorous fish can be quite particular eaters, spelling yet another danger for recovering reefs. “Of the nearly 30 species of bigger herbivores on the reef, there were four that were doing almost all of the feeding on the seven species of seaweeds that we studied,” said Mark Hay a professor in the School of Biology at the Georgia Institute of Technology. “We did not see much overlap in the types of seaweed that each herbivore ate. Therefore, if any one of these four species was removed, that would potentially allow some macroalgae to proliferate.”  “The patterns [of consumption] were remarkably consistent among the reefs in terms of which fish were responsible for removing the seaweed,” said Rasher. “Because different seaweeds use different defense strategies to deter herbivores from eating them, a particular mix of fish – each adapted to a particular type of seaweed – is needed to keep seaweeds off the reef.” Using a technique that is quite interesting the scientist were able to induce the particularity of consumption across species lines by removing a chemical indicator from one type of seaweed fish were attracted to, and then applying that signature to a different type of seaweed. This technique implies algae may emit a chemical signal warding off predators. Hoping to discuss their findings with local tribes fishermen, the team would like to limit fishing of the most important herbivorous fish. “Not fishing is really not an option for people in these communities,” Rasher said. “Giving the village leadership an idea of which species are essential to reef health and what they can do to manage fisheries effectively is something we can do to help them maintain a sustainable reef food system.” Read more here!