Tuesday, August 30, 2011

Invasive Species - White Spotted Jellyfish

Scientifically known as Phyllorhiza punctata, the White Spotted Jellyfish is a species of Jellyfish that is native to the tropical western Pacific Ocean, and also has wide distribution throughout Australian coastal and lagoon waters, where it feeds mostly on plankton. This species of Jellyfish has been found off the coasts of Hawaii since 1945 - although the ecological impact that these non-native jellyfish have had on Hawaii has not been studied - and then spread to the Continental United States. The White Spotted Jellyfish was first discovered in California in 1981, but, since then, has experienced a population explosion in the Gulf of Mexico. It has been theorized that these non-native Jellyfish came to the United States by attaching themselves to the hulls of ships, or in their ballast tanks, and get carried through the Panama Canal and dumped into the Gulf of Mexico. Once in the Gulf of Mexico, these jellyfish can become unusually large in size - up to 60 cm across, in comparison to the average of 45-50 cm. As an invasive species, this Jellyfish preys on native species, such as shrimp, menhaden, anchovies, and crab. Additionally, the White Spotted Jellyfish has been known to negatively affect the shrimp industry by clogging up nets and damaging fishing equipment - there is evidence to suggest that this species of Jellyfish has reduced the white shrimp harvest in Mobile Bay, Alabama and Mississippi Sound by 26.7 %.