Alea DelleCave
Toxic Algae Destroys Shark Brains
Being Floridians most of us know the factors of Red Tide, we see lots of dead fish on the shorelines, the strong scent fills our lungs with its sickening toxins, and every year thousands of dollars are used to help fix the problem. Is there a possibility that humans can be put to blame as a contributing factor? Agricultural run-off effects the formation and bloom of the algae by increasing the amount of it. The increasing amount of deadly blooms have the ability to alter sharks brains, making them hyper-excited, which eventually leads to the shark killing itself. With the advancing amounts of Red Tide blooms could the threat of losing high numbers of sharks come along with it?
II. Discovery
The toxins produced in Red Tide effect the brains of sharks, so far studies show that the lemon shark is the most sensitive to its toxins. The sharks are exposed through consumption of brevetoxin-contaminated water and food. The toxins are easily crossed through the sharks blood-brain barrier that protects the sharks brain. Brevetoxins are brain changing conpounds synthesided by the harmful algae blooms. Once entered into the brain, the brevetoxins bind very strongly to a protein that controls the sodium flow. If the sodium flow is interrupted the nerve cells in the brain will over-fire and cause hyperexcitability.
Off the cost of central Florida scientists collected 30 lemon sharks and had kept tabs on them for three years. The sharks were collected during red tide seasons, as well as non-red tide seasons. One of the sharks collected had died as a result of too much exposure to the toxic algal bloom. Dong-ha Nam, lead investigator, annalyzed the levels of brevetoxins within the sharks tissues, the neurochemical enzyme activity, and the neurochemical receptor binding. They found high levels of the brevetoxins in he liver, gills, and brain of the sharks who had been exposed to the red tide. Once infected within its brain, the shark cannot heal itself and will die.
Niladri Basu is an aquatic toxicologist interested in the risk assessment of aquatic pollutants,development of neurchemical biomarkers, and the use of fish and wildlife as sentinels of human and enviormental health hazards. He is currently working at the University of Michigan.
"Sharks are exposed via consumption of brevetoxin-contaminated water and food, such as shellfood", explained Niladri Basu to Discovery News.
4.Impact on Humanity
The blooming of toxic algae in the oceans and lakes are familiar health risks and cause problems every summer, which leads to the increased costs for water cleaning, water consumption and the tourist industry. Scientists still are not sure why algal blooms arise, or what it is that causes certain species of micro algae to multiply and form dense blooms. Scientists within the research platform MARICE (Marine Chemical Ecology) at the Faculty of Science, and the University of Gothenburg present a new possible explanation of why algal blooms arise in a study published in the international journal proceedings of the National Academys of Sciences. Currently the theory is that the algae produces toxin not only in order to inhibit the growth of the other competing species, but also to protect themselves from its predators. The research gathered shows that the only side-effect of the more aggressive behavioral of algae is that it will go to any means necessary in order to gain access to the nutrients within others cells. "The behavior of the algae can v e compared to that of a blood sucking insect", said Per Jonsson of the Department of Marine Ecology. The "warrior" tactics used on its fellow opponents makes sense for its aggressive behavior towards the sharks as well. It infects the sharks in order to sustain its own lifestyle. Could algae now be considered a parasite? Ofcoarce these are only ideas and hypothesis.
"The area we studied represents a recetnly disovered nursery habitat for lemon sharks., and it may serve as one of the most valuble lemon shark nurseries in the U.S. waters.", sais Douglas Adams of the Flordia Fish and Wildlife Conervation COmmission told Discovery News. The Well known "Florida Red Tide" found int the waters of the Gulf of Mexico is a harmful aglae bloom (HAB) caused by the karenia brevis, a dinoflagellate which are both producers of brevetoxin. The sharks who are survivors of the massive outbreaks, the long term impact of the aquatic populations remains unkowns. Since the precence of brevetoxins in shark embryos raises questions about the effects these toxinsmay have on the reproductive success of sharks. In the near future there may be provabilities of lemon shark defects as well as other marine life.
5. Journal Article Review
Legacy of Poison
By Chris Perham
The toxins are biological substances, non synthetic or natural materials. Red tide is made up of tiny little organisms that manage to wipe out things ten times their size. The massive growth and expansion of the red tide is growing in increasing amounts. It was been around for centuries though; according to some the "Red Sea" was actually red tide. Red tide completly switches up the idea of a food chain by infecting the worlds waters and killing massive amounts of fish, and even people if a contaminated seafood is consumed. A strong leading reason why this toxic algae is blooming is because of the human race. As we keep polluting our oceans not only are our sea life in danger but it can also put our own personal health in jeopardy.
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"Google Image Result for Http://www.miamipoison.org/Images/RedTide.jpg." Google. Web. 12 Dec. 2010. <http://www.google.com/imgres?imgurl=http://www.miamipoison.org/Images/RedTide.jpg&imgrefurl=http://www.miamipoison.org/x59.xml&usg=__8F8bKlG0pr6L8es0kBc6upw1zKI=&h=267&w=400&sz=20&hl=en&start=17&zoom=1&tbnid=NN7NHtnA3g__DM:&tbnh=154&tbnw=222&prev=/images?q=red+tide&um=1&hl=en&biw=1280&bih=666&tbs=isch:10,786&um=1&itbs=1&iact=hc&vpx=142&vpy=239&dur=78&hovh=183&hovw=275&tx=222&ty=84&ei=vHsFTcyxGMH38AaJ8dTmAg&oei=NHsFTe2UF4T7lweBv7m3Dw&esq=2&page=2&ndsp=16&ved=1t:429,r:11,s:17&biw=1280&bih=666>.
Viegas, By Jennifer. "Toxic Algae Destroys Shark Brains : Discovery News." Discovery News: Earth, Space, Tech, Animals, Dinosaurs, History. Web. 12 Dec. 2010. <http://news.discovery.com/earth/shark-brains-algae-blooms.html>.
