Essay on Acanthaster planci on the Great Barrier Reef

Acanthaster planci on the Great Barrier Reef The organism Acanthaster planci, commonly known as the crown of thorns starfish, has a drastic effect on the health of coral reefs all over the world, including the Great Barrier Reef of Australia. This poisonous echinoderm feeds upon the coral, and although this should be a healthy and natural part of the ecosystem, the population explosions of the starfish have caused devastation in many portions of the Great Barrier Reef. Reef sections take anywhere from ten to fifteen years to recover, and some never recover completely with the same species distribution. The starfish outbreaks seem to travel southward down the reef with the two primary outbreaks reported in the last 40 years both†¦show more content†¦Population explosions, or outbreaks, of the starfish occurring over the past 30 to 35 years have caused concern because of A. planci predation of the coral. An outbreak of the starfish can devastate a reef. The scientific community has so far been unable to pinpoint a specif ic cause for these outbreaks. Some suggest that the population explosions are natural phenomena that have occurred for thousands of years. However, others believe that the outbreaks are a recent occurrence caused by human interference in the reefs, mainly human elimination of starfish predators. Currently, methods of starfish control, possible causes of outbreaks, and general starfish biology are being vigorously researched in hopes that a solution to the problem will come to light. Physical Biology Acanthaster planci is an echinoderm of the class Asteroidea. An adult organism may grow anywhere from 25 to 35 cm in diameter with the largest recorded individual being 80 cm. The organism’s size is dependent on what it eats, availability of food, and the number of other starfish in the population. The arms of a starfish make up the bulk of its diameter. Most A. planci have between 14 and 18 arms. Its arms may be lost to predators or shed when the organism is stressed but can be regrown within 5 to 6 months (Moran, 1997). The arms are supported by a complex skeleton of ossicles which have projections forming protective spines (Head et al. 1989). EachShow MoreRelatedClimate Change and Global Warming1074 Words   |  5 Pagesevidence to support this hypothesis. The dilemma becomes whether we can limit the damage and adapt to a new status quo or not. Rising sea levels and the damage caused by this phenomenon has irreversible impacts on coastlines worldwide. Damage to sensitive r eef systems cannot be fixed. This also has permanent impacts of the ecology not just of those immediate areas but also the ocean as a whole. Any discussion of the irreversibility of Climate Change needs to be briefly pre-empted by an explanation of theRead MoreThe crown-of-thorns starfish (Acanthaster planci) is named for the brightly colored spikes that1300 Words   |  6 Pagescrown-of-thorns starfish (Acanthaster planci) is named for the brightly colored spikes that coat the legs. A. planci can grow up to 16 inches across and can have between 12 and 19 legs. The spikes coating A. planci hold poison that can cause temporary paralysis at the sting site and can also cause nausea in humans. A. planci can also regrow arms. At the end of each of the arms is an eyespot that can detect light and darkness, but can not detect color and shape (Fisher 2011). A. planci preys on coral andRead MoreEssay on Palau Coral Reef1613 Words   |  7 PagesPalau Coral Reef Coral reefs are one of the most complex and colorful tropical ecosystems, rivaling rain forests in their richness of life. 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