Jellyfish Life

Jellyfish are found all throughout the waters of the world from the waters surface all the way down to the deep sea, but in more recent times there has been a dramatic rise in jellyfish numbers. Dr. Anthony Richardson who is an Australian scientist has found that there is evidence of jellyfish overpopulation being caused by both over-fishing and also an excess in the levels of nutrients in the water due to sewage and fertilizers.

In normal circumstances jellyfish are found in the ocean on a seasonal basis as a response to the availability of food which is also seasonal in the majority of regions. When the temperature and levels of sunlight rise such as in spring and summer the amount of food available increases and as does the jellyfish population in the area. In Japan, Nomura Jellyfish which have the ability to grow up 2m or more in diameter and weight up to 200 kilograms have surged in numbers and caused absolute chaos for the industrial fishermen. Jellyfish blooms have also had a dramatic incline in others parts of the world such as the black sea, the Caspian seas, The Far west coastal waters and The Mediterranean. These more recent blooms show that the jellyfish population incline is becoming more and more severe and frequent.

With such large numbers of jellyfish in the waters there will certainly be a very dramatic impact on fishing and food supplies. The more jellyfish that are in the sea, the more they will eat, the more they eat, the less food there is for the other marine creatures which share their dietary interests. Another problem is for swimmers, with so many jellyfish in the water it may very well become almost impossible to go for a swim at the beach without suffering from a nasty sting. The tourism industry would be severely impacted with increased jellyfish populations in the waters.

Such large presences of jellyfish in the waters may not just pose a threat to humans but also to other marine creatures that cross paths with the jellyfish. Because jellyfish do not intentionally sting but rather sting automatically when something comes into contact with them, there can be many other marine creatures that are stung and even killed on a regular basis which may eventually lead to possible extinction of some of our much loved sea dwelling creatures. In a healthy ecosystem the fish and the jellyfish both share the same dietary needs and make one another rather competitive for food, the less food that is available the less jellyfish there will be. With recent times the overfishing has began to destroy this dietary balance and with less competition in the waters the jellyfish move in to populate the area. A good example of this is in Namibia where excessive fishing has drastically reduced sardine stocks and as more food is available the jellyfish have moved in and replaced the sardines as the most dominant species in the water.

For more information on jellyfish and where they can be found please visit our Jellyfish Information section.

Learn more about Jellyfish, different Jellyfish Species, general Jellyfish Information, Jellyfish Pets and Jellyfish Safety

Written by Nathan Dickerson and Sudarsana Sinha.