Overfishing In The Great Barrier Reef

The most critical effect of overfishing, however, is resulting in species imbalance in the ecosystem. It is a common sense that there is such connection called food chain, which is a series of events where one creature eats another and then is eaten by another creature, exists in an ecosystem, and each of every living organisms has a place on this chain. If, all of a sudden, one specific type of species decreases immensely in amount, this phenomenon will undoubtedly affect other living creatures that is also on the food chain as an inevitable outcome of the operation of food chain. The Great Barrier Reef is not an exception. The reduction in the number of desired fish resulting from overfishing will influence other species in the ecosystem …show more content…
Tiger shark, one of the most commonly seen species in the area, can serve as an example since they are not only defined as creatures on the top of the food chain but also on the front places of the fishermen’s hunting lists. The tiger shark has the widest food range of all sharks, consuming a large variety of prey: seals, birds, turtles, and even other small reef sharks. In the journal Patterns and ecosystem consequences of shark declines in the ocean, it includes that “recent studies in the Great Barrier Reef, where tiger shark populations have declined but green turtles have begun to recover and sea grass has started to decrease, suggest indirect effects of sharks on sea grass” (Ferretti, Worm, Britten, Michael, Lotze 1067). The connections among the three marine species mentioned above are clear: tiger sharks prey upon green turtles while green turtles consume green grass. When the size of tiger sharks shrinks, green turtles, labeled to be endangered species as indicated in the previous paragraphs, are in lower predation pressure so that the likeliness for them to give up foraging opportunities for safety enhancement is less, creating a better condition for green turtles to recover. As the number of green turtles expands, more green grass is eaten up as a result, leading to reduction in green grass. This example shows that overfishing top-ranked species can in the end influence the autotrophs that lie in the base of the food chain. What’s more, the cascading effects of changes in the ecosystem can be better illustrated in the case of the cownose ray. According to a scientific journal called Cascading Effects of the Loss of Apex Predatory Sharks from a Coastal Ocean, “from 1970-2005...shark population in the Great Barrier Reef may have declined by more than 97 percent” (Myers, Baum, Shepherd, Powers, and Peterson 1848). That