A crisis is emerging in the waters of the Caribbean as coral reefs begin to vanish. If no action is taken, the reefs may disappear completely within two decades. According to a report from multiple international organizations, sea urchins and colorful parrotfish may be the coral reefs’ best chance at survival.
The study analyzed the research of 90 different experts over the course of three years and reported that Caribbean reefs have declined more than 50 percent over a 50 year span. Although a lot of experts blame climate change, a decrease in the numbers of sea urchins and parrotfish is mainly responsible for the problem.
Sea urchins and parrotfish feed off of seaweed, and as they decrease in population, the algae increases and smothers the coral. Parrotfish spend 90 percent of their day eating seaweed off of reefs. They also excrete sand, maintaining the sandiness of beaches. Sea urchins also feed on algae, helping to preserve coral reefs. However, with the algae consuming the Caribbean coral, the result is a far less resilient and productive ecosystem.
Most reefs in the Caribbean have been taken over by seaweed since the 1990s. The shift in the balance of coral dominance was initiated due to a massive amount of sea urchins dying off and parrotfish being overfished. The reefs that have the healthiest ecosystem are the ones that still have a large amount of parrotfish population due to restrictions on fishing practices such as spearfishing and using fishing traps.
The vanishing coral reef problem is not only hurting the Caribbean’s ecosystem, but their economy as well. The reefs generate more than $3 billion per year from fisheries and tourism. Although the increased amount of algae is mainly being attributed to the lack of sea urchins and parrotfish, some researchers still believe that climate change is a big factor in the tropical coral decline. An adviser with the International Union for Conservation of Nature, which, along with the Global Coral Reef Monitoring Network and the United Nations Environment Program, issued the report about the Caribbean’s coral decrease, has mentioned that only 10 percent of the reef’s decline is directly related to climate change. However, a coordinator for the National Oceanic and Atmospheric Administration who helped contribute to the report believes that the study understates the influence of ocean warming due to climate change.
There have been six notable bleaching events within the last 30 years which, in conjunction with warm ocean waters, force organisms in the reef to eject more algae. As the temperatures in the water increase, the coral becomes more vulnerable to disease. Although bacteria can benefit coral that is healthy, it has a negative impact in warmer water. In 2005, 90 percent of the coral in the eastern Caribbean were affected by bleaching, which in turn caused more than half or the reef to die.
In order to protect the Caribbean’s vanishing coral reefs, parrotfish and sea urchins need help thriving by maintaining safe fishing practices in an effort to prevent overfishing. By monitoring and enforcing restrictions and regulations, working with organizations and local communities, providing education to prevent further reef damage, and listing parrotfish as a protected species, the colorful coral in the Caribbean may once again flourish now and in the years to come.
By Laura Simmons