Posts Tagged ‘Lionfish’

Jul 15, 2013

Trouble (& Solutions) in Paradise

While I was born and grew up in Jamaica, I took residence in the Cayman Islands in 1999 and have enjoyed living here ever since. The main island of Grand Cayman, where I live, has incredible scuba diving, outstanding fishing opportunities and is home to the world-renowned Stingray City. However, even paradise has its share of problems.

In 2012 we had a terrible year for wildlife: the lionfish invasion continued, the Turtle Farm and its inhabitants got a log of bad press, our beloved stingrays were being stolen from the sandbar, a rogue male dolphin ruined many dives for visitors, the grouper spawning sites came under increasing pressure and a proposal to expand marine parks had many objectors. When its difficult to manage the natural resources of a tiny island nation, it puts into perspective the challenges that we have trying to keep the planet healthy and sustainable. Here, as with the rest of the world, there are some easy solutions for some issues and complicated solutions for others. In Cayman, lionfish have become the target of dedicated hunting tournaments as weekly culling sweeps by divers and concerned individuals. We’re seeing these types of eradication methods being employed in Florida, the Gulf Coast, the Bahamas, and all over the Caribbean. The best part is that lionfish are very good to eat. I encourage restaurant owners to offer lionfish on the menu and advertise just how good they are to eat.

Guy Harvey after a Little Cayman Lionfish sweep

In Cayman, our marine park system has served us very well for the last 26 years. Compared to all other Caribbean countries we have some of the finest shallow snorkeling sites and wall dives anywhere. However, with double the population since then and more demand on marine resources, there is not going to be much left in the next 10 year at the current rate of fish extraction.Expansion of the park system and better enforcement will continue to conserve our best ecological asset. The issues of marine parks, better known worldwide as Marine Life Protection Areas (MLPAs), is as controversial in the Cayman Islands as it is in the United States.

SPAG - Cayman Islands

In Cayman, the distinction between commercial and recreational fishing is very fuzzy. There is no doubt that the need for NTZs is a must in our situation, and new studies will show the importance of SPAG sites not seasonally but all year round. One example in which the NTZs is a must is in the protection of the Nassau Grouper spawning (SPAG) site in Little Cayman. The Marine Conservation Board took appropriate action and extended the ban on fishing the SPAG sites for another eight years in December 2011. The protection of the brood stock, the “investment”, during spawning season is common sense here, as well as in the all corners of our oceans. Allowing any kind of harvest-be it recreational or commercial- at a spawning site is recipe for disaster and truly killing the golden goose.

Unfortunately, the proposed legislation to protect Nasssau Groupers throughout their range during the five-month spawning season still languishes in cyberspace. One of the biggest hurdles we all face is the education of lawmakers about the importance of the marine environment to this small island’s economy. As with any protection-here or in the rest of the world-its’s imperative for grassroots groups to keep the pressure on government so that our recreational resources will not be depleted by those seeking to make a profit. It is our collective responsibility to conserve the marine environment and maintain the biodiversity of this planet

Fish responsibly and dive safely wherever you live,

Guy Harvey,PhD

Jan 25, 2012

Lionfish In The Cayman Islands

In recent years the Indo-Pacific lionfish has spread from the SE coast of the USA throughout the Bahamas and Caribbean as far north as Bermuda and as far south as Venezuela. They can reduce the populations of native fish species very rapidly particularly by preying upon juveniles and reducing recruitment of all species to the reef habitat.

There are several examples of humans causing the substantial invasion of a (non native) species that thrives extremely well in its new habitat. In short order, this species explodes in biomass because of the lack of natural predators in that new environment and a food source that does recognize the invader as a predator. But none have had the dramatic (possibly immeasurable) damaging effect that the lionfish has had on Caribbean and western Atlantic native fish populations.

The spread of Lionfish in the Bahamas and Caribbean is problematic for native species

In response to the invasion of lionfish around the reefs of the Cayman Islands the Department of Environment now offers lionfish culling courses and licenses the use of Hawaiian slings to assist in capture and killing these fish. Being a small country with a low population but many of whom dive, fish or both, the culling of lionfish has become a weekly operation. Many restaurants are now offering lionfish on their menus.

Several dive companies have one day per week set aside for hunting lionfish, particularly in Little Cayman, the diving crown jewel of these islands. A study on the effectiveness of this culling is being undertaken by the Central Caribbean Marine Institute, (CCMI) which is based on the north side of Little Cayman. Following the Wednesday culling dives, researchers are measuring the catch per unit effort needed to make a dent in the population and cover the 3 mile stretch of wall at Bloody Bay to determine how fast new lionfish colonize the vacated areas. They are also assessing whether the structure and balance of Bloody Bay’s native fish population is affected by the continuing targeted removal of lionfish.

The targeted removal of lionfish has several benefits. Firstly, they are good to eat, so in spearing lionfish rather than grouper, snapper or hogfish, this removes some fishing pressure on the more popular reef species and will help reduce the mortality of juvenile reef fish caused by the invasive lionfish. The removal of significant numbers of larger lionfish means that those remaining are unable to prey upon larger individuals of the resident native fish populations.

Perhaps the best way to get people involved is to hold a lionfish culling tournament. There is the educational component when you register for the event, then the challenge of getting the most, the biggest (or smallest) and the creation of a tournament atmosphere while relieving the reefs of a very dangerous predator.

In a meeting with the Minister of the Environment last week, I learned of the plan to have a specialized task force assigned to culling lionfish around the Cayman Islands. I agree with this move. The threat to the coral reef habitat is so great that there needs to be radical action taken. The individual dive operators should not have to do the all grunt work on their own. After all, the dive business in the Cayman Islands is the focal point of the tourism sector.

Little Cayman also has the largest remaining population of Nassau groupers. This species, which is a favourite of divers and is the iconic Caribbean reef predator, may now have a new role in reef fish population restoration. Nassau groupers routinely follow divers and will consume lionfish speared by divers. Some divers say that Nassau groupers lead them to lionfish a bit like trained hunting dogs. For decades the Nassau groupers were traditionally fished heavily by artisanal fishermen at their spawning sites (locally called “grouper holes”) over the winter full moons. The Marine Conservation Board here protected these sites from 2003, and has just renewed that protection for another eight years. Good job! The Nassau grouper might be the knight in shining armour for reef fish populations. If this grouper, along with other large groupers and mutton snappers, can learn to attack and consume lionfish without the aid of divers then natural controls will begin to take effect in reducing lionfish biomass. After all, in the western Pacific and Indian Ocean, lionfish populations are maintained at equilibrium by their natural predators such as large groupers, jacks and the white tip reef shark.

Guy Harvey

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Apr 22, 2011

The Lovely Menace: Invasion of the Lionfish

The colorful and charismatic lionfish are proliferating on the coral reefs of Bermuda, Florida, the Bahamas, and the Caribbean. Although non-native to the Atlantic, it’s becoming hard to miss them in many areas.  That’s good, you might be thinking.  Divers spend a lot of money to travel to coral reefs in the Indo-Pacific where these fishes are native and provide visual delights for underwater photographers.  Whip out those cameras — an added attraction has shown up to add zing to the diving experience on Atlantic coral reefs, you say.

Unfortunately, like most invasive species scenarios – recall the ecological and economic mess created by the infamous zebra mussel – the lionfish introduction and rapid geographic spread is proving far from ecologically harmless to Atlantic coral reefs.  In fact, scientists are quite concerned that lionfish may be completely reinventing the western north Atlantic coral reef ecosystem – permanently!

What are these lionfish doing in the Atlantic in the first place and what’s going on?  Here’s some background: Lionfish belong to the scorpionfish family (which includes the venomous scorpionfish and stonefish).  Even if you don’t dive you’ve likely seen them as they are very popular in the aquarium trade.

Two species are now known to occur in the western Atlantic: the red lionfish (Pterois volitans) and the devil firefish (Pterois miles), with the former occurring in much greater numbers.  The two species are similar looking and it took DNA evidence to confirm that there are indeed two species that have invaded the Atlantic.  They’ve been around for a while, with the first observation in the Atlantic occurring near Fort Lauderdale, Florida in 1985!  Considered a rarity at first, lionfish populations have exploded over the past 25 years and especially over the past decade, spreading far north and south.  They now range at least from Bermuda to Venezuela.  It’s really worth tracking their remarkable and disconcertingly fast spread at: http://nas.er.usgs.gov/taxgroup/fish/Lionfishanimation.gif.  If you dive in the Bahamas you’ll know that they are over running the reefs.

So what’s the worry?

Invasive Lionfish in the Bahamas. Photo: Courtesy of B. Watts

It’s an ecological nightmare.  In spite of a mountain of unknowns, researchers agree on a few key points: lionfish are voracious predators and prolific breeders.  They devour the young of other reef fish species, including several commercially important species, and even crustaceans such as newborn lobsters.

In addition to their own direct impact on reducing other fish populations by predation, lionfish are outcompeting native fishes for food.  Not a good scene for native fishes.  Lionfish can suck up about 80% of all small or immature fish in a section of reef in only five weeks.  Their predation on young herbivorous fish also means reduced control of algae, which can overgrow and kill coral.

How bad is it? There are enormous concerns that lionfish will completely change and possibly destroy Atlantic coral reefs by overrunning them and shrinking their native biodiversity, and that the ongoing damage is severe and possibly irreparable.  So far, there is no known quick-fix, and the problem is escalating exponentially.

Lionfish are the lions of the Atlantic reefs; they sit enthroned near the top of the food web where almost nothing eats them.  Scientists don’t fully understand why lionfish have no natural predators in the Atlantic. Observed cases of lionfish being eaten by other fish are so few that they can be counted on one hand. Would-be predators seem to shy away from the lionfish’s poisonous appearance – even when lionfish are in their larval stage. Possibly for this reason, invasive lionfish have encountered practically no natural opposition since their introduction, when the first individuals were probably dumped into the Atlantic as unwanted aquarium pets. Without effective population control, the lionfish – also called the red firefish – spread like, well, wildfire.

It’s easy to see why. Lionfish reach sexual maturity in only about one year. For the rest of their adult lives, female lionfish lay batches of 25,000-30,000 eggs almost twice a week (about every four days). Do the math, and you will quickly discover what this means. Each year, there are easily over two million eggs for each female lionfish. These eggs quickly develop into living vacuum cleaners. Each lionfish eats fish up to two-thirds of its own size, and lionfish stomachs stretch up to thirty times their normal size when feeding.

Ironically, studies are showing that lionfish are now present in higher densities in some Atlantic regions than they are in their native Indo-pacific habitats! Maybe the Atlantic environment is just making female and male lionfish more romantic. Or maybe it’s a lack of predator thing. Or maybe their Atlantic prey have fewer defenses?

So, what can be done? Many scientists think that the rapid pace of lionfish population growth and geographic spread means that nothing can completely stop the destruction by this invading beauty. But perhaps the momentum can be slowed if control measures are quickly and widely implemented.

Lionfish meat is excellent in taste and texture, and lionfish dishes have been added to the menus of many exclusive restaurants. In fact, the US federal government’s chief fisheries management agency, the National Oceanic and Atmospheric Administration (NOAA) has developed an “Eat Lionfish” campaign to increase the public’s awareness of the issue and create a consumer market for this tasty invader. Several coastal communities host fishing events called lionfish derbies where prizes go to the anglers who catch the most, and an enormous celebratory barbecue comes at the end of each derby. Many recreational anglers would attest that, after a long day of fishing, grilled lionfish with a cold beer is a hard treat to beat!

These triumphs, however, are small ones. Fishing alone cannot solve the lionfish problem. It will also take both education and dedication. As an increasingly prominent marine “poster child” against non-native species release, the lionfish example further proves that release can have unpredictable, unprecedented, and literally dire consequences. Please never release your exotic pets. A simple desire to let one animal “have a better life” in the wild can so easily create an irreparable ecosystem and economic mess.

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