Picture a coral reef. What do you see? Schools of brightly colored fish, long branches of corals and sponges swaying in the tide, maybe a diver, and endless expanses of the most beautiful blue. Now picture all of that gone. The only thing you see is rock, large bushes of overgrown macroalgae, and lionfish.
Lionfish, a species of fish native to the Indo-Pacific reefs, are now firmly established in the Atlantic and Caribbean. They have invaded this part of the world in the last 25 years. It is thought that they were first introduced in Florida form an aquarium destroyed in a hurricane. In the Cayman Islands specifically is being very negatively impacted by the invasion. The lionfish threaten the two major industries: fishing and SCUBA tourism. You see, lionfish are predatory fish. They can eat up to 4% of their body weight in juvenile fish and crustaceans daily. Without any natural predators, the lionfish’s eating habits have become a threat to the local biodiversity. They eat mostly grazer fish young, which would grow up to play a vial part in the health of the reef. The grazers eat the macroalgae that can stop the corals from getting enough sunlight they need to grow. (Corals are animals, but they live in a delicate symbiotic relationship with microscopic algae that live inside of them. If the algae don’t get enough sunlight, the coral and algae both die.) Coral is a basis of many fish on the reef; lose the coral, you lose the fish. Lose the fish, lose the coral. Lose the coral, lose the beauty of the reef. Without the beauty of the coral and fish, the Cayman Islands lose the appeal for divers (Diving in the Caribbean is a US$2.1 billion per year industry.) Also, lose the grazers and you lose the large predatory fish that are caught and eaten by the people of the Caribbean. (Projections based the current rate of decline in reef fish life due to lionfish predict fishery yields to decrease by 30-45% by 2015.)
Frazer et al. were interested in looking at how a mass removal project would effect the reef and lionfish populations. They organized a team of volunteers to dive in three locations around Little Cayman and kill the lionfish. They measured the amount of time spent under the surface with the number of lionfish eradicated, and found that targeted removals were effective and time efficient. With the lionfish that were killed and brought to the surface Frazer and his team of physiologists were able to get information on the types of food the lionfish ate at different developmental stages, which can help scientists better understand the exact their impact on the reefs and reef life. When Frazer and his team returned 6 months later, they also found that the lionfish were not returning to the vacated habitats. Frazer deemed the removal project a success.
I believe that the lionfish invasion can be controlled by spreading the word. In 5 years, it is said that there will only be lionfish on the reefs of the Caymans. Small removals are constantly happening with the local dive masters. Lionfish is also finding its way onto menus all over the Caribbean. By creating an understanding of the importance of the removal of the fish and creating a demand for the consumption of it, the reefs can be saved.
For the full article: http://www.tandfonline.com/doi/full/10.1080/10641262.2012.700655#.UjdxRHDPXao
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