Coral reef bleaching isn't what you might think it is. I used to believe it was an act done by humans, for whatever reason, where we literally were using bleach to dye the corals into a duller color or even to white. It is true that majority of the causes of the bleaching are manmade, and its true that it caused loss of color for the corals. The bleaching is caused by the loss of the algae that lives on and supplies the coral with its food. Once the algae is gone the bright colors of the coral are dulled, but then if conditions are bad enough then the may even turn all white, and the coral is more susceptible to diseases. Bleaching of coral reefs are caused by the warming of oceans waters, over exposure to sunlight, low tides, nutrient runoff and other runoff pollutions.
Pollution such as excess nutrients, pathogens, toxins, and sediment from the human population and development expansion are causing diseases and even mortality within the corals. They disrupt ecological functions, feeding behaviors and prevents the growth and reproduction of both marine life and the corals. The pollutions can be emitted by failed septic systems, coastal development, the construction of roads, infrastructure and impervious surfaces, storm-water runoff, deforestation, chemical and oil spills, and daily agriculture.
The Great Barrier Reef's overall coverage has decreased by 50%, part of this can be caused by the outbreak of the starfish with numbers within the thousands. The crown of thorn starfish eat the fastest growing starfish, but these corals take 10 to 15 years to bounce back.
The venomous starfish are found primarily in the Indo-Pacific region and in the warmer months every 17 years their population explodes with the birth of up to 65 million eggs at a time from a single parent. The coral reefs from the year 1985 to 2012 have overall declined 50%, half of the damage being done by the crown of thorns starfish. Although they are heavy predators of the coral, they only really eat the faster growing ones. This allows slow growing colonies to form, creating a more diverse ocean bed.
Methods for solving the starfish problem vary, but they have gotten more efficient. At first, the divers would either completely remove them from the reef, or they would be chopped in half or into smaller pieces. This wasn't the best method due to the fact they have the ability to regenerate limbs, and can even generate the other half of the body back, thus increasing the population. The only other outside source besides human culling and natural predators that are helping to protect the corals, the guard crab lives in cauliflower corals and other branching corals and if the starfish is too close to these colonies it will pinch at its tube feet or its stomach lining to get it away.
The study, which is scheduled to come to a conclusion next year, will inform us on what species eat both the small and large crown of thorns. All including the large pufferfish, these species could be more protected from both environmental and human factors by laws & regulations to help cap populations.
Volunteer divers cull a record number of almost 47,000 crown of thorns starfish in one week. Diving teams have been culling thousands of these every trip, in an 8 day period teams have successfully injected 2700 starfish in the Arlington Reef and 9000 at Batt Reef, and 14000 at Spitfire Reef near Cooktown.
Queensland researchers have developed a faster way of killing these COTS, by means of a robot. The COTSBot was launched for testing in September of 2015, its programmed with hundreds of different photos of the species so that they only inject them. This robot will help both us and the reef by reducing the amount of divers and their essential equipment required, and by killing the starfish and only the starfish.
These starfish usually outbreak in huge numbers due to the fact that each year they lay 50 million eggs, of coarse not all of the eggs hatch but the numbers have gotten bigger than normal. It is shown that nutrient runoff from the shores after both floods and natural watersheds help the phytoplankton survive, which the larvae feed on. Humans have stepped up and acted in culling because these predators that eat the starfish don't eat enough of them, especially when they can break out at hundreds at a time per acre. For example, the triton only eats about one a week and their population isn't that big.
The Australian government has put into affect the crown of thorns starfish control program which is responsible for culling these venomous stars all year round. Teams of up to 10-12 divers go to the shores between Lizard Island and Cairns for 10 days straight then get a 4 day off period. Since the programs launch in 2011, 300,000 starfish have been removed from 80 different patrolled reefs. To cull a starfish the diver would have to remove it from its location then inject it with toxins about 20 times, but now a more effective toxin was created by James Cook University that allows the divers to inject the starfish where it is, the toxins create an allergic reaction within which breaks apart its body within 24 hours.
University of Queensland's School of Biological Science's Professor Bernie Degnan says that the starfish produce these proteins during the warm spawning seasons that attract other starfish to the area; which is why they outbreak in such large numbers. In a way its a communication system, but in plume form. They believe if they can get into their internal communication systems, they could develop a tool that could trick them to behave in a way they want them to behave. Self titled bio-control will be used to attract the starfish in smarter and more spread out locations so the damage wont be that big.
The Coral Reefs of the world have been significantly dropping in color and in size for years now. Currently there is only 30% of the reefs that are still healthy and its estimated it may only get worse, where it takes up to 15 years to bounce back from such conditions.The Crown of Thorns Starfish are responsible for almost 50% of that damage! The reason why the starfish are such a big problem is cause of the population outbreaks. A parent lays about 65 million eggs at a time, and what makes it worse is that they release these plumes that actually attract other starfish which results in hundreds of thousands of larvae in one small area; even to the point that they're piled up on one another. The starfish eat the colorful algae that grows on the surface of the fastest growing corals, which is why it is part of the bleaching problem. Most bleaching comes from human's land based sources whether it be nutrient runoff, natural phenomenon such ass overexposure to sunlight and low tide or simple toxins/pollutants and further expansion and development within cities. Humans have woken up to the fact that the coral reef needs to be protected, that at this rate if we didn't do anything about it we could possibly loose the beautiful scenery and marine life found along the ocean bed. As a step of realizing this we must take action, yes? The predators of the starfish don't do enough of the job, since their populations are much smaller and they don't need as much food.Since 1962 there have been about 6 outbreaks of theses poisonous stars and started in 2011, divers and now even robots are culling them in populations of the hundreds at a time. Technologies and methods for controlling them have developed greatly, from actually making the population grow buy cutting them apart, to swift lethal injection that triggers an allergic reaction to even taking a look inside of the genome of their DNA to see what helps communication and migration patterns in means of plumes that they release so then it can be manipulated into locating and spawning in smaller numbers and areas.