Why are lionfish considered such a problem? Are lionfish really all that bad?

Photo taken by Erin Cziraki while doing graduate work at Coastal Carolina University in Conway, SC. My advisor was Dr. Erin Burge. The fish were captured and processed at the Discovery Bay Marine Lab in Discovery Bay, Jamaica which is part of the University of the West Indies.Yes. Non-native lionfish are a terrible problem in the Western Atlantic Ocean, Caribbean Sea and in the Gulf of Mexico, however they are not a problem in their native ranges of the Indian Ocean, Southern and Western Pacific Ocean and in the Red Sea. The world is still waiting to see how bad the problem with non-native lionfish in the Mediterranean is going to get; it is a relatively “new” invasion that is only just really beginning to develop.

One thing is for certain, the lionfish invasion is probably the worst man-made ecological disaster ever witnessed and it has yet to completely play itself out. We discuss in detail specific facts about lionfish in other pages of our website but to give you a simple summary of the problem:

Invasive lionfish are out-breeding, out-competing and out-living native fish stocks and other marine species. The consequences impact the food security and economies affecting over a hundred million people. 

Lionfish are potentially the fastest breeders in the Western Atlantic Basin.

In favorable conditions female lionfish can release egg masses approximately every 4 days, up to 2 million eggs a year. Lionfish larvae have an incredibly high “recruitment rate” to suitable habitat, meaning that potentially more eggs become larvae, which then become juvenile lionfish settled somewhere that they can grow and live relatively free from environmental pressure. (To put it another way: Lionfish breed faster than rabbits and most of them find good homes with plenty of food.) Lionfish are sexually mature reach 1 year of age and can live well beyond 15 years. There are aquarium owners who have reported having a lionfish live to 20 years old.

Invasive lionfish eat everything that they can fit into their mouths and that their stomachs can handle.

Lionfish Stomach Contents Photo Provided by Sallye Martin "PelagicSal"Lionfish can eat prey over half the size of their own body as long as it will fit into their mouths. Their stomach can expand up to 30 times the normal volume and a lionfish will fill up to capacity as soon as it is able. Lionfish are not picky eaters and feed indiscriminately. Scientists have cataloged over 70 different species that lionfish will eat through stomach content analysis. In addition to the fish they eat, they also eat invertebrates and mollusks – shrimp, crabs, juvenile octopus, squid, juvenile lobster, sea horses, etc.

The native species that invasive lionfish are feeding upon do not recognize lionfish as a predator and flee. In fact, just the opposite has been shown to be true. Small fish will often congregate around a lionfish, most likely believing that the lionfish’s long spines, fin rays and feathery pectoral fins offer them shelter and protection from predators. However, when the lionfish is ready to eat, these fish are herded into alcoves where they cannot escape. Lionfish use lighting fasts strikes and gulp down dozens of whole fish at a time. Science has demonstrated that a single lionfish can reduce native marine creatures by 80% to 90% in its range within just 5 weeks.

The native marine species that lionfish are decimating are important for ecological, commercial, traditional and recreational reasons.

Ecologically important species include the “grazers” and the “cleaners” that maintain the health of the reef and the health of other fish.

lionfish surrounded by prey pulled from its stomachGrazers eat the algae that grows over the reef, they are essentially the lawnmowers that keep the algae levels low enough that coral can get enough oxygen to survive and allow coral to spawn and space for baby coral to settle onto substrate where it can establish itself and grow. Grazers include parrotfish, goatfish, wrasses, surgeonfish & tangs and many others that are favorite prey of lionfish. Not only do reefs provide shelter and protection to entire schools of juvenile marine creatures but some say that reefs and the algae that grows on them may provide as much as 80% of the Earth’s oxygen! Over 42 million people in the Western Atlantic Basin make their living from coral reefs, mainly through fishing and tourism. One doesn’t have to look farther than the Caribbean Sea to see that! The Mesoamerican Reef is the second largest reef system in the world sits squarely in the invasive lionfish’s newly found habitat. If the reef smothers and dies under the additional pressures caused by lionfish, what will happen? We’re not sure that anyone has an educated answer to that question, yet is seems entirely possible.

Cleaners remove harmful material from native fish and marine creatures. Unlike native species of fish, a lionfish will consume the small fish and invertebrates that “work” in cleaning stations, where reef fish, turtles, and other marine life go to have parasites and other detritus removed, which in turns keeps them healthy. Usually the “cleaners” are relatively free from predation or harm while at work, crawling all over and into the mouths of potential predators. Lionfish are the exception to this rule. They will gorge themselves on cleaner shrimp, wrasse and gobies thereby decimating the cleaning station altogether. The loss of these cleaning stations presents the serious potential decline in the overall health of the creatures that depend upon them to stay healthy and disease-free.

Commercially important species include, for sale, the fish and marine creatures delivered for human consumption and nutritional supplements and put into industrial uses such as pharmaceuticals, animal feeds, pigments, clothing (skins and pearls), fertilizers, etc. There is no doubt that as commercially important species diminish due to lionfish predation that the price of those items will go up. It’s a simple exercise of supply and demand. “Table-fish” supplies commonly served in local restaurants, like grouper, snapper, tunas, etc., will become more difficult to catch in the supplies required and prices will necessarily go up as a result. Eating habits may then shift to other proteins forcing fishermen and entire fishing communities out of business.

Traditionally important species of fish and marine creatures are those marine from which aboriginal people and groups produce their livelihood or use them in accordance with their traditions and history. While not necessarily common in the United States, artesian fishing practices and hyper-local fisheries dependent pockets of people certainly exist in Central and South America. Many indigenous populations require the fisheries resources commonly found in their region to sustain their way of life or produce income in order to survive in an increasingly commercial world. As lionfish predation continues to create unprecedented pressures on these local fisheries, traditional fishing and unique cultures inexorably tied to the sea are also threatened to near extinction.

Lionfish Stomach Contents provided by Fadilah AliRecreationally important species of marine life are those creatures commonly associated with sport, recreation or for consumption by participants (and not for sale). For example, billfish, mahi mahi, wahoo, jacks, tuna and other “game fish” are specifically prized by anglers while scuba divers really enjoy seeing things like octopus, sea horses, lobsters, crabs and other unique marine life we find special to see on any dive. Lionfish regularly raid the nurseries where juvenile game fish usually find security while growing up and they are eating them in unsustainable amounts. We also know that lionfish eat seahorses, juvenile octopus and lobsters.

The impacts reach much further than just the divers and fishermen, however. There are people, indeed entire economies, that depend upon these recreational activities as well… Places like the Bahamas, Caymans, Cozumel, the Bay Islands of Honduras (Utila and Roatán), Bonaire and many others depend upon the tourism-related revenue that sport fishing and scuba diving generates. Diving alone is a $2.1 billion economy in the Caribbean. Businesses like hotels, dive centers, fishing charters, restaurants and all of their employees in areas like these rely upon a steady flow of tourists in search of the best recreational and sport experiences available. If the reef dies and the pretty fish die, scuba divers will choose a different destination. If the sportfish stocks dry up, then sportfishermen stop coming, too. Paychecks dry up, jobs are lost and the economies collapse of those areas unable to make the shift to other industries or sources of revenue.

Lionfish Hunting Equipment

Lionfish can live in a huge range of water quality, salinity, temperature and depth with relatively no stress.

Lionfish in Estuary - Photo Credit: Florida International University

Source: The Abaco Scientist

They have been spotted in water as little as 1 foot (.3m) deep to beyond 1,000 feet (305m) deep. They are equally at home in brackish water river estuaries and mangroves, where most of the juvenile fish grow up. Being able to tolerate water temperatures down to 50 degrees Fahrenheit (10 degrees Celsius) they have established a current range from Rhode Island, United States as far south as Brazil. They are highly tolerant to temperature change and biologically resistant to most diseases and parasites that affect native fish. When food is scarce due to temperature and climate, lionfish can live beyond 3 months without eating anything at all and lose very little body mass as a result.

Lionfish can live in excess of 15 years and have no natural predators in the Western Atlantic Ocean, Caribbean Sea or Gulf of Mexico that are capable of controlling the burgeoning lionfish population.

We are only just beginning to understand the consequences of the lionfish invasion at this point, even the scientists that have been studying the non-native lionfish for two decades are having a really tough time even articulating what the landscape of our local oceans and seas are going to look like ten short years from now. The population explosion has taken most of them completely by surprise and they readily admit that the problem is far worse than could be imagined even six or seven years ago.

Here is what we do know today – these facts are proven:

  • Native fish stocks are down as a direct and identifiable result of lionfish predation.
  • Commercial fisheries and the lobster industry in places like Florida are crashing as a direct result of lionfish predation.
  • Reef health in the Western Atlantic Basin is in serious decline.
  • The lionfish population continues to grow at an ALARMING rate and they are establishing their range further south into South America every day.
  • Direct action by lionfish hunters is the only viable method for controlling lionfish populations in the very, very small area that we can reach, relative to the entire range of the new lionfish habitat.
  • The areas that are regularly maintained by lionfish hunters see a demonstrable rebound of native fish and other sea creatures in time.
  • We are rapidly running out of time as we are approaching a tipping point from which our underwater ecosystems cannot recover.

Here’s the bottom line:

Invasive lionfish are disastrously out-breeding, out-living, out-eating and out-competing every other native fish in the Western Atlantic Ocean, Gulf of Mexico and the Caribbean Sea. If left unchecked lionfish will ultimately cause the destruction of the reefs, native fish stocks and the livelihoods of everyone that depend upon them.

What is the problem with Lionfish? Why are Lionfish Bad?

Yes, lionfish are really that bad.

We have several additional resources that might be helpful to you as well: Frequently Asked Questions About Invasive Lionfish, Comprehensive List of Lionfish Facts, Most Common Lionfish Myths as well as a 7 Interesting (and Shocking) Facts You Might Not Know about this very serious issue facing our underwater ecosystems  in the Western Atlantic Basin.

If you find these facts useful in your research about lionfish and other invasive species, please consider providing a back link to Lionfish.co, giving us a Google+1, a Facebook “like” or a mention on Twitter so that we can continue with our mission and effectively reach others like yourself in a meaningful and educated way.

Thank you!