Deep-Sea Corals

Deep-Sea Corals

Dr. Erik E Corcles lectured on the deep-water horizon impacts of the deep sea and how coral could possibly be restored. The deep-water horizon incident occurred April 20, 2010, where 11 loves were lost, 7 people were injured, and 5 million barrels of oil entered the open water. At the time, many scientific studies were taking place in the gulf focusing on physiology, community ecology, genetics, monitoring, oceanography, and habitat preference. Scientists were finding that there were more deep-sea corals then tropical shallow water corals. There is a hypothesis that state the deep-sea corals evolved and then slowly moved closer to the surface to form shallow tropical water corals. Another hypothesis states that the opposite is it true.

In fact, there are deep-sea bubble gums corals off the coast of New Jersey. These types of corals need a slow flux and a high carbonate area to survive. In order to find more deep-sea corals like this in the Gulf of Mexico echo sounding, multi beam, and AUVs were used. Oil drillers used this data to find new sites for oil rigs that are not directly on top of the corals. However, they are not far from the coral sites, so incidents like the deep-water horizon spill could affect the corals.

At first and second glance, the corals looked fine and showed little sign that the oil spill had affected them. However when the corals were visited a third time the effects of the oil began to show physically on the corals. In one instance, a species-specific relationship was seen with a brittle star and a coral. The brittle star and coral originally looked fine, however by the third visit, the brittle star had disappeared and the coral physically looked deteriorated with few healthy polyps. A later visit showed that hydroids had begun to appear taking over the coral and giving a fuzzy appearance.

Scientists were able to link the damage to the coral to the deep water horizon spill through analysis of the back mystery substance left on the corals. When corals become stressed, mucus is released that catches particles that could be harmful. The mucus formed bubbles around the black mystery substance and samples were compared to the oil from horizon. There was a match, which gave evidence that the oil from the spill negatively affected the deep-sea corals. Other factors that played a role in the coral deterioration were the oil, dispersant toxicity, genetic responses, and microbial associations.

Compensation and restoration of the corals is another issue at hand. It is hard to assign a monetary value to the deep-sea corals however, biological economists will try to do that in an effort to have horizon compensate for the damages.

Restoration of these deep-sea coral is an unexplored issue. No one has ever tried to restore deep-sea coral before so this will be new. Four species are found at these great depths. Some of the corals that are there are 500 to 600 years old. They have a long generation time and do not easily form. Their growth rate is 0.4- 0.6cm per year, while there mortality rate is one incl every 9-10 years. However, this spill has increased the mortality rate tremendously, which can make restoration harder to accomplish. The recruitment rate of these corals is 1.2 to 1.4 incl per year. Scientists are looking into placing cement balls on the sea floor in order to increase the amount of substrate. This may help deep sea corals re-colonize and hopefully increase in numbers. However because the corals growth rate is slow the effects of the cement balls may not be seen for years. Therefore, restoration of the coral may take a long time to accomplish if it is even possible.