Navigation Links
Lionfish decimating tropical fish populations, threaten coral reefs
Date:7/17/2008

CORVALLIS, Ore. The invasion of predatory lionfish in the Caribbean region poses yet another major threat there to coral reef ecosystems a new study has found that within a short period after the entry of lionfish into an area, the survival of other reef fishes is slashed by about 80 percent.

Aside from the rapid and immediate mortality of marine life, the loss of herbivorous fish also sets the stage for seaweeds to potentially overwhelm the coral reefs and disrupt the delicate ecological balance in which they exist, according to scientists from Oregon State University.

Following on the heels of overfishing, sediment depositions, nitrate pollution in some areas, coral bleaching caused by global warming, and increasing ocean acidity caused by carbon emissions, the lionfish invasion is a serious concern, said Mark Hixon, an OSU professor of zoology and expert on coral reef ecology.

The study is the first to quantify the severity of the crisis posed by this invasive species, which is native to the tropical Pacific and Indian Ocean and has few natural enemies to help control it in the Atlantic Ocean. It is believed that the first lionfish a beautiful fish with dramatic coloring and large, spiny fins were introduced into marine waters off Florida in the early 1990s from local aquariums or fish hobbyists. They have since spread across much of the Caribbean Sea and north along the United States coast as far as Rhode Island.

"This is a new and voracious predator on these coral reefs and it's undergoing a population explosion," Hixon said. "The threats to coral reefs all over the world were already extreme, and they now have to deal with this alien predator in the Atlantic. These fish eat many other species and they seem to eat constantly."

Findings of the new research will be published soon in Marine Ecology Progress Series. The lead author is Mark Albins, a doctoral student working with Hixon.

In studies on controlled plots, the OSU scientists determined that lionfish reduced young juvenile fish populations by 79 percent in only a five-week period. Many species were affected, including cardinalfish, parrotfish, damselfish and others. One large lionfish was observed consuming 20 small fish in a 30-minute period.

Lionfish are carnivores that can eat other fish up to two-thirds their own length, while they are protected from other predators by long, poisonous spines. In the Pacific Ocean, Hixon said, other fish have learned to avoid them and they also have more natural predators, particularly large groupers. In the Atlantic Ocean, native fish have never seen them before and have no recognition of danger. There, about the only thing that will eat lionfish is another lionfish they are not only aggressive carnivores, but also cannibals.

"In the Caribbean, few local predators eat lionfish, so there appears to be no natural controls on them," Hixon said. "And we've observed that they feed in a way that no Atlantic Ocean fish has ever encountered. Native fish literally don't know what hit them."

When attacking another fish, Hixon said, the lionfish will use its large, fan-like fins to herd smaller fish into a corner and then swallow them in a rapid strike. Because of their natural defense mechanisms they are afraid of almost no other marine life. And the poison released by their sharp spines can cause extremely painful stings to humans even leading to fatalities for some people with heart problems or allergic reactions.

"These are pretty scary fish, and they aren't timid," Hixon said. "They will swim right up to a diver in their feeding posture, looking like they're ready to eat. That can be a little spooky."

Their rapid reproduction potential, Hixon said, must now be understood in context with their ability to seriously depopulate coral reef ecosystems of other fish. Parrotfishes and other herbivores prevent seaweeds from smothering corals. A major, invasive predator such as lionfish could disrupt the entire system.

Options to manage the lionfish threat are limited, Hixon said. They can be collected individually, which may be of localized value, but that approach offers no broad solution. Recovery or introduction of effective predators might help. Groupers, a fish that has been known to eat lionfish in the Pacific Ocean, have been heavily over-fished in the tropical Atlantic Ocean, Hixon said.

"We have to figure out something to do about this invasion before it causes a major crisis," Hixon said. "We basically had to abandon some studies we had under way in the Atlantic on population dynamics of coral reef fish, because the lionfish had moved in and were eating everything."


'/>"/>

Contact: Mark Hixon
hixonm@science.oregonstate.edu
541-737-5018
Oregon State University
Source:Eurekalert

Related biology news :

1. Tropical insects go the distance to inform rainforest conservation
2. New study warns limited carbon market puts 20 percent of tropical forest at risk
3. Tropical crab invades Georgia oyster reefs -- but the long-term impact cant be predicted
4. Spatial patterns in tropical forests can help to understand their high biodiversity
5. Researchers discover forests of endangered tropical kelp
6. If corn is biofuels king, tropical maize may be emperor
7. Why do so many species live in tropical forests and coral reefs?
8. Time-sharing tropical birds key to evolutionary mystery
9. Springer launches Tropical Plant Biology
10. No convincing evidence for decline in tropical forests
11. Tropical soils impede landmine detection
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/16/2016)... The global Biometric ... USD 1.83 billion by 2024, according to a ... proliferation and increasing demand in commercial buildings, consumer ... the market growth.      (Logo: ... of advanced multimodal techniques for biometric authentication and ...
(Date:6/9/2016)... 2016  Perkotek an innovation leader in attendance control systems is proud to announce ... for employers to make sure the right employees are actually signing in, and to ... ... ... ...
(Date:6/7/2016)... 7, 2016  Syngrafii Inc. and San Antonio ... that includes integrating Syngrafii,s patented LongPen™ eSignature "Wet" ... collaboration will result in greater convenience for SACU ... while maintaining existing document workflow and compliance requirements. ... Highlights: ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... ... June 23, 2016 , ... ... (Yeast and Mold) microbial test has received AOAC Research Institute approval 061601. , ... tests introduced last year,” stated Bob Salter, Vice President of Regulatory and Industrial ...
(Date:6/23/2016)... ... 2016 , ... STACS DNA Inc., the sample tracking software company, today announced ... has joined STACS DNA as a Field Application Specialist. , “I am thrilled ... COO of STACS DNA. “In further expanding our capacity as a scientific integrator, Hays ...
(Date:6/23/2016)... , June 23, 2016 On ... session at 4,833.32, down 0.22%; the Dow Jones Industrial Average ... 500 closed at 2,085.45, down 0.17%. Stock-Callers.com has initiated coverage ... INFI ), Nektar Therapeutics (NASDAQ: NKTR ), Aralez ... Inc. (NASDAQ: BIND ). Learn more about these ...
(Date:6/23/2016)... 23, 2016 ReportsnReports.com adds ... to its pharmaceuticals section with historic and forecast ... much more. Complete report on the ... profiling 15 companies and supported with 261 tables ... . The Global Cell Culture ...
Breaking Biology Technology: