Seaweed-threatened corals send chemical SOS to fish

Link:
http://www.sciencenews.org/view/generic/id/346344/description/Seaweed-threatened_corals_send_chemical_SOS_to_fish

This article is about the signal certain corals give off when they come in contact with poisonous seaweeds. If nothing is done to stop it the seaweed can over run and destroy an entire coral reef. The coral and seaweed both compete for sunlight that they both need in order to survive so this relationship between the Goby and coral is very beneficial. When seaweed starts over taking the coral, it makes the coral smoother which speeds up the process of the destruction of coral. When this happens, fish start leaving to find other hiding places. When there are fewer fish to eat the algae it is free to expand even faster.One of the few defenses the coral has is its ability to quickly summon Goby fish to trim back the seaweed by producing a certain compound that attracts the Goby fish. Researches found this phenomenon while doing an expiriment in which coral and toxic seaweed were placed together and then different fish were introduced into the environment to see their different reactions to the coral and seaweed being together. Most of the fish left the area within a couple days, but the Gobies stayed and chewed back the seaweed until it and the coral were no longer in contact. After further testing, it was concluded that coral with the Gobies as defenders seffered one fourth of the damage than coral without Gobies. It also found that this relationship was beneficial for the Gobies too because it increased the toxin levels in their skin which helps them to fend off potential predators.



NOS Themes

• Science is based on evidence
• Role of chance
• Role of motivation and curiosity