Also known as the “rainforest of the sea”, coral reefs support about one-third of marine life. These amazing underwater structures take many years to build. Unfortunately, due to natural and man -made threats, their number today is vanishing at a very alarming rate. Have a look at some of the most alarming ways we are losing our coral reefs.
For years, the coral reefs in the Belizean lagoon are under the observation of Richard Aronson and his team from the Florida Institute of Technology. They estimated that the reefs were about 8,000 to 9,000 years old.
However, in May 2009, a 7.3 magnitude earthquake rocked the western Caribbean wherein half of the coral reefs were ravaged. Before the disaster, the reefs were still recuperating from earlier damages due to diseases and coral bleaching. Worse, the corals were not firmly attached to the lagoon walls, so a large part of the reef had been easily destroyed by the avalanche.
While the coral reefs can make a comeback, Aronson and his team estimated that it may take about 2000 to 4000 years before they can fully recover.
9. Cold Snap
Due to the warming of the seawater, corals are forced to expel the symbiotic algae that live in their tissues. This makes their color turn white, a reaction better known as coral bleaching. While coral bleaching usually occurs due to high temperature, extreme low temperature can also trigger this phenomenon.
Florida is the home of one of the largest coral reefs in the US. But in January 2010, the state had suffered from the meanest cold weather in history since 1940. It caused serious damage to crops, but more so in the coral reefs underwater. It was noted that the water temperature in some areas dropped to a dangerous 51° Fahrenheit.
When ecologist Diego Lirman and his team examined the Florida Reef Tract after the devastation, they were shocked to find high death toll in corals. The reefs suffered from a large-scale coral bleaching that killed many species, including thecentury-old Montastraea.
8. Oil Spill
The explosion of the BP operated oil rig near the Gulf of Mexico shocked the world in April 2010. The incident injured many workers and caused one of the worst oil spills in the history.
After the disaster, scientists are immediately concerned about the effect of oil plumes in the coral reefs lying underneath. These plumes are hazy globules formed by the mixture of oil, natural gas and a dispersant called Corexit. They do not float in the surface; rather, they settle on the sea floor.
Due to lack of funding, there are no prior studies that thoroughly explain the danger of oil and dispersants to marine life living in deep water. But experts are quick to evaluate the possible damages they can cause. They believe that oil plumes can inflict harm by suppressing oxygen supply, thus, suffocating the corals. They also believe that toxic plumes can also destroy the coral’s ability to reproduce.
7. Killer Seaweeds
Seaweeds may look harmless, but they can actually be deadly to corals. Many species of killer seaweeds can be found in the Pacific Ocean and Caribbean including Chlorodesmis fastigiata. They possess certain chemicals that when released can cause bleaching to the corals nearby.
The purpose of the natural chemical is uncertain, but experts have hypotheses. They think that the seaweeds release them to protect themselves from microbial infection. Another is that they use it as a weapon against other seaweeds. It is evident however, that corals react negatively when exposed to these chemicals.
As we are losing our coral reefs due to major issues like climate change and overfishing, the added threat from this natural enemy may even hinder their recovery.
6. Micro Plastic Pollution
A piece of plastic thrown into the sea can pose serious problems to aquatic animals including corals. Micro-plastics are particles small enough to be ingested by plankton-eating animals. These tiny fragments are dangerous when consumed, as they are indigestible.