Invasion of Jellyfish essay

The ENVIRONEWS wants to inform us about the cause and effect of the sudden increase in the population of jellyfish that startled different parts of the globe. The situation in the Gulf of Mexico off Louisiana and in the Bering Sea is a vindication of this phenomenon. Likewise, the condition in the coast of Florida, New Zealand, Hawaii and even Australia is as worse.

The ENVIRONEWS vaguely hinted the cause and effect of this phenomenon but experts claim that this rapid growth in jellyfish population can be blamed to human intervention but some retaliate that it is also caused by other natural phenomena like for example the climate change and natural ocean currents. Although the report didn’t mention it, these jellyfish incidents are being talked about worldwide and whichever caused this augmentation, we cannot deny the fact that people living near those jellyfish sights are affected by the mere presence of this particular specie.

In the field of science and research, jellyfish became popular in 1980’s because of its sudden bloom in the Black Sea. The Black Sea, by then, is an ecology already troubled by overfishing (Pohl, 2002). Experts say that the jellyfish took a free ride on the bottom of a ship from somewhere in the world and multiplied in the Black Sea, eating anchovy eggs to survive. That means jellyfish can ride all they want and propagate its specie to the entire world. Another possible cause of the rapid growth of population of the jellyfish in different parts of the globe is the so called ‘stressed system’ (cited in Pohl, 2002).

Humans are usually responsible for a stressed system. The increase in water temperature, the rise in nutrients in the water, the depleted stocks of other fish and the proliferation of oil and gas platforms and artificial reefs are some of the common traits of a stressed system. The higher the nutrient levels in water, the higher the possibility of the survival of jellyfish. The end product is the surplus of fertilizer and sewage. Also, because of overfishing, there’s an imbalance state where the competition over food supply will be in favor of the jellyfish (Pohl, 2002).

Jellyfish loose their main competitor for food without any effort from its part. The population of jellyfish will continually bloom. In Hawaii alone, overfishing of ahi and mahi-mahi leads to the bloom of jellyfish there (cited in Pohl, 2002). The decrease in number of sea turtle, a jellyfish’s predator, also caused the bloom. This bloom in density can also be the unusual consequence of global warming. Global warming partly caused the increase in water temperature. Scientists believe that global warming results from the greenhouse effect which is the consequence of burning of fossil fuel.

Because almost ninety-five percent of a jellyfish’s body is consists of water, it enables them to feel the increase of water temperature. Jellyfish preferred a warmer ocean temperature and as the temperature increases over the century, this specie will continue to grow, worsening the problem on fish supplies caused by overfishing (Sample, 2007). These stresses may also be the cause of the arrival of non-native species of jellyfish from Florida to Louisiana (Crowder, 2005). An example of this non-native species is the Australian spotted jellyfish, Phyllorhiza punctata, which was first seen in 2000.

This jellyfish is believed to come from the Caribbean Ocean. Phyllorhiza is harmless in terms of its sting but as its number rise so as its threat on commercial fishing. In their native place, Phyllorhiza can be as big as a fist but experts observed that in Mexico, they can be as big as a saucer plate. This invasive creature had been found in small numbers seven years ago but as the year progress its number tends to grow exponentially. It also threatens the population of fish, crabs and shrimps by eating their main source of food supply. The Phyllorhiza is not the only non-native specie that came from the Caribbean Ocean.

There is also the Giant Caribbean jellyfish, Drymonema dalmatina, another invasive jellyfish that dwells the Gulf of Mexico. Many experts are worried about this sudden proliferation since it may give the coastal ecosystem a not-so-good effect. Commercial fisheries are directly affected. Jellyfish block and leave slimy gelatin in nets and because of this, some of the equipments of local fishermen were damaged too. Also, jellyfish tend to eat plankton and tiny crustaceans, a fish larvae’s staple diet, or just directly feed the fish larvae itself. They eat the young age-class fish.

They compete with fish for zooplankton prey. This is not good for the local as well as international fishery economy. In the Gulf of Mexico alone, this boom of jellyfish had taken so much loss. In Louisiana and Mississippi, local reinforcements chose to fund urgent research scheme to examine the danger imposed by these invaders; that’s why millions of dollars in losses are being filled in monetary ledgers (Crowder, 2005). On the other hand, climate change and a release from competition by planktiborous forage fishes in Bering Sea can be seen as the cause of this increase (Livingstone, 2004).

The number of predatory zooplankton came with the so called El Nino in 2000; thus, the gelatinous zooplankton (jellyfish) dramatically increased over the summer of 2000. In the ENVIRONEWS, problems regarding the direct contact of the jellyfish with humans were not discussed. Although economic supplies and international trades are very important, individual and health care must also be put into account. This problem was observed in Miami, Florida. Here, over 100,000 people were stung by jellyfish in just a single week of 2002.

In a single touch, jellyfish can discharge millions of tiny harpoons, sending microscopic needles filled with venom into the skin (Pohl, 2002). Even though the toxin has worn off, these minuscule harpoons tend to give its victim a month-long painful effect. Recently, two deaths caused by the venomous jellyfish shocked Australia. The harmful effect of jellyfish to human lives was being ignored not until someone died. On the contrary, although almost all the negative effects of these invasive jellyfish were presented, some experts still see this as an opportunity to increase the variety of food supply.

There is an edible jellyfish that dwells in the Australian waters. It is the Catostylus mosaicus. Also, the box jellyfish is also edible if you cut its tentacles. Because of this, concerns and research regarding the reduction of those invasive jellyfish and the production of the edible ones are being pressed upon to the scientific community (Pohl, 2002). All in all, the invasive jellyfish that dwells the Gulf of Mexico and some different part of the globe can cause commercial and health problems. But we also know that jellyfish is not the sole villain.

Human intrusion, as always, partly creates the ruckus and, as always, we are the only one that can fix this problem.


Pohl, Otto. (2002, May 21). New Jellyfish Problem Means Jellyfish Are Not the only Problem. Retrieved November 4, 2007, from http://query. nytimes. com/gst/fullpage. html? res=9F0CE2DA1538F932A15756C0A9649C8B63 Crowder, Matt. (2005, October 13). Jellyfish Population Causes concern on Capri. Retrieved November 4, 2007, from http://www. zwire. com/site/news. cfm? BRD=2256&dept_id=529872&newsid=15378910&PAG=461&rfi=9