Lionfish Invasion: Super Predator Threatens Caribbean Coral Reefs

By: Mark Hixon, Mark Albins, and Tori Redinger

Indo-Pacific lionfish are rapidly invading the waters of the Caribbean and tropical Atlantic. Due to their population explosion and aggressive behavior, lionfish have the potential to become the most disastrous marine invasion in history by drastically reducing the abundance of coral reef fishes and leaving behind a devastated ecosystem. Dr. Mark Hixon and his team from Oregon State University with support from NOAA’s Undersea Research Program (NURP) have embarked on the first studies to measure the severity of the crisis posed by this invasive predator.

Lionfish found near Lee Stocking Island. Photo credit: Mark Albins, University of Oregon State

A Photograph from above of a lionfish.
Photo credit: Mark Albins, University of Oregon State

The lionfish, native to the Indo-Pacific region, have infiltrated their way into the Caribbean. Their introduction is believed to be a result of hurricanes and tank releases during the early 1990’s. They have been spotted along the eastern seaboard spanning as far north as Rhode Island to as far south as Columbia. Protected by venomous spines, lionfish are voracious and effective predators. When hunting, they herd and corner their prey using their pectoral fins, then quickly strike and swallow their prey whole. With few known natural predators, the lionfish poses a major threat to coral reef ecosystems in the Caribbean region by decreasing survival of a wide range of native reef animals via both predation and competition. While native grouper may prey on lionfish, they have been overfished and therefore unlikely to significantly reduce the effects of invasive lionfish on coral reef communities.

In the last several years, members of Dr. Mark Hixon’s lab working at the NURP Caribbean Marine Research Center at Lee Stocking Island (LSI), a field station at the southwestern end of Exuma Sound, Bahamas, have documented increasingly frequent sightings of lionfish. These findings have provided an unprecedented opportunity to study the ecological interactions of lionfish with Caribbean coral reef fish communities from the very beginning of the invasion. In the summer of 2005, they found their first lionfish near LSI. Between the fall of 2006 and summer of 2007, the lionfish population in the Bahamas increased substantially. During the summer of 2007, over 100 lionfish were spotted around LSI signifying a rapid expansion within the Bahamas.

Researcher Mark Albins documenting a lionfish in the Bahamas. Photo credit: Mark Albins, University of Oregon State

Diver observing a lionfish among corals.
Photo credit: Mark Albins, University of Oregon State

PhD student Mark Albins of Hixon’s team devised a controlled experiment testing the effects of lionfish on native fish communities by documenting the recruitment of newly settled reef fishes on 20 patch reefs near LSI: 10 reefs with a lionfish and 10 reefs without. Fish censuses were conducted at one week intervals for five weeks. Recruitment was significantly lower on lionfish reefs than on control reefs at the end of the experiment. On one occasion, a lionfish was observed consuming 20 small wrasses during a 30 minute period.

It was not unusual to observe lionfish consuming prey up to 2/3 of its own length. Results of the experiment show that lionfish significantly reduce the net recruitment of coral reef fishes by an estimated 80%. The huge reduction in recruitment is due to predation and may eventually result in substantial, negative ecosystem-wide consequences. It is also important to note that lionfish have the potential to act synergistically with other existing stressors, such as climate change, overfishing, and pollution, making this invasion of particular concern for the future of Atlantic coral reefs.

Lee Stocking Island facilities Exuma, Bahamas. This island is surrounded by extensive patch reefs, seagrass meadows, and mangrove forest.
Photo credit: Perry Institute for Marine Science

While complete eradication does not seem realistic, affected nations are encouraged to initiate targeted lionfish control efforts as soon as possible, including targeted fisheries (lionfish flesh is tasty and cooking denatures the spine venom). Efforts to reduce densities of lionfish at key locations may help to lessen their ecological impacts. Recovering and maintaining healthy populations of potential native predators of lionfish, such as large grouper and sharks, may also help reduce the deleterious effects of these voracious invasive predators.

Hixon’s team will return to the Bahamas this summer and thereafter to conduct further field experiments, field observations, and laboratory experiments to answer important questions regarding the invasion and how lionfish interact both directly and indirectly with native Bahamian reef fish and invertebrate communities. They will also work in the Pacific Ocean to understand what naturally controls lionfish abundance in their native range.

NOAA’s Undersea Research Program (NURP) provides scientists with the tools and expertise they need to investigate the undersea environment, including submersibles, remotely operated vehicles, autonomous underwater vehicles, mixed gas diving gear, underwater laboratories and observatories, and other cutting edge technologies. NURP provides extramural grants to both the federal and non-federal research community through its six regional centers and the National Institute of Undersea Science and Technology.

03/08/09

Home About Research Technology Centers News Funding Library

NOAA's Undersea Research Program
1315 East-West Highway, R/NURP - Silver Spring, MD 20910
Phone: (301) 734-1000 Fax: (301) 713-1967
Email

Contact Info

Disclaimer

Site Index

Updated: March 9, 2009