Jellyfish aren't what they seem!

As the oceans get warmer, jellyfish are on prowl to attack. They have been shutting down power plants from Sweden to the U.S. while killing thousands of farmed fish. GPS devices, normally used for house cats, were attached to jellyfish off the coast of northern France. One reason that more congregating in blooms may be from climate change. From this, researchers are seeking to develop a system to help forecast their movement and stop fish deaths. According to Graeme Hays, the leader of the group from Deakin University in Australia and Swansea University in the U.K., "jellyfish blooms may be increasing as a result of climate change and overfishing. They have a lot of negative impacts - clogging power station intakes, stinging people and killing fish in farms."The climate change has brought warmer waters, about 85 degrees Celsius more since 1900, which is a dream come true for the jellyfish. According to Lisa-Ann Gershwim, a marine scientist who researched jellyfish for about 25 years, the warmer water "amps up their metabolism so they grow faster, eat more, breed more and live longer."One bloom of jellyfish that is known to cause a problem is the Moon Jelly. In 2013, the creatures shut down Sweden's biggest nuclear reactor for two days because they blocked the cooling water inlet. In the U.S., Japan, and Scotland, similar occurrences also happened. To prevent these creatures from shutting down any more power plants, the Diablo Canyon was created. It is a nuclear station on the California coast that has automated screens to get rid of the animals at the intake and can deploy an air bubble curtain system to scatter and divert the blooms. With the advantage of the warmer waters, jellyfish have been causing a problem for the fish farms. Once they have come in contact with the net of a fish farm, it becomes a big problem. Depending on the size, jellyfish can either clog or sting the gills of a fish or restrict the flow of water, depriving the fish oxygen. Jellyfish are still a big problem for the ocean today. I found this article very interesting and informative. When you think of jellyfish, the things that come to mind are the ones you see on the beach, which are like jello. In fact, no one realizes how much of a destroyer they are to the oceans. I liked how this article gave you another side to the fun and jello-like creatures.  

Sea Nettles in the Barnegat Bay

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http://mrwriteon.files.wordpress.com/2009/07/sea-nettle.jpg ( Photo Link)

Sea nettles have always been a part of the Barnegat Bay’s ecosystem; their apparent increase in abundance is a relatively recent phenomenon. A number of potential causes for this increase have been suggested by scientists. Increased development around the bay, including bulkheads, pilings, and floating docks, may be providing more places for the scyphistoma to attach. Changes in the bay’s salinity may also have an effect. Sea nettles prefer a lower salinity zone, so large-scale natural changes in salinity, such as dry years, may affect their abundance and distribution in the bay.

Scientific evidence is beginning to link increasing sea nettle populations with eutrophication. Eutrophication decreases the amount of dissolved oxygen in the system. When oxygen levels are low, predator fish that would normally prey on Jellyfish swim to waters with more oxygen. Also, the fish would under normal circumstances compete for food with the sea nettles. Since there is less competition for food the sea nettles eat more and the population increases. Sea nettles are a very tolerant species, meaning that they can survive despite some changes to their environment. As long as the water remains warm enough, these jellies can “out compete” many species if dissolved oxygen in the water becomes too low. As their populations grow the ecosystems can be severely damaged.

If this continues on the bay may become so filled with these sea nettles that it may be too dangerous to swim in. There is a way to raise awareness of the dangers of dumping toxins in to the bay and hopefully prevent further growth of Sea Nettles. “The Barnegat Bay Partnership is one of 28 congressionally designated National Estuary Programs throughout the United States working to improve the health of nationally significant estuaries. The program is sponsored by the United States Environmental Protection Agency, the Ocean County Board of Chosen Freeholders, and Ocean County College.”

Box Jellyfish Have Eyes, Allowing it to See the World Above

According to an article published on April 28, 2011 in Current Biology, box jellyfish may be more complex than what meets the eye. Though it is well known that the jellyfish is a much simpler organism in comparison to a human, box jellyfish have no fewer than 24 eyes of four different kinds. Four of these eyes, called the upper lens eyes, always peer up out of the water, regardless of how the rest of the organism is oriented. Since box jellies live in mangrove swamps, it was hypothesized that the upper lens eyes help navigate the jellyfish around their environment. Anders Garm of the University of Copenhagen said, "It is a surprise that a jellyfish - an animal normally considered to be lacking both brain and advanced behavior - is able to perform visually guided navigation, which is not a trivial behavioral task. This shows that the behavioral abilities of simple animals, like jellyfish, may be underestimated." Scientists have known that box jellies have a unique array of eyes, which help the animal respond to light, avoid obstacles, and control their rate of swimming. When studied, the researchers noticed that the jellyfish used their upper lens eyes to navigate their way by means of looking at the canopy of mangrove trees. When the canopy was obscured from their vision, the box jellies could no longer get around and did not move. Garm says, "Instead of having a single pair of general-purpose eyes like most other animals, box jellyfish have several different types of eyes used for special purposes. This means that each individual eye type is dedicated to support only a limited number of behaviors. The eyes can then be built to collect precisely the information needed, minimizing the need for further processing in a big brain. The automatic orientation of the upper lens eyes to constantly look through the water surface is a clear example of this."

I thought this article was really interesting because I, like I'm sure most people do, assumed that jellyfish were stupid creatures that cannot do anything complex because of their simplicity. Also, I thought it was REALLY cool that they have so many different types of eyes, each with its own special purpose. It makes sense why each type of eye has only a certain number of functions, though, as Garm said. It cuts down on the jellyfish's necessity to process that information through the brain. So that explains why jellyfish have such a small brain and can still perform complex behavioral tasks, like navigating through a mangrove swamp. I'm pretty sure I wouldn't be able to navigate myself through a mangrove swamp, and I'm much more complex than a jellyfish! Props to the box jellies. =]