Lionfish hunters tackle invasive species problem

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SeafoodSource, Southern Caribbean

Over the past several years, the southern Caribbean has had to respond to the devastating impact of the lionfish, an invasive alien species whose voracious appetite makes it particularly dangerous since it has no natural predators in the region and it preys on the young of commercially important fish species. Fadilah Ali, director of the Gulf and Caribbean Fisheries Institute, began working with various islands, including Anguilla, Curacao and Bonaire, between 2010 and 2016 to find a solution to the problem. After her presentation at the Latin America and Caribbean Congress for Conservation Biology, at the University of the West Indies campus in Trinidad, on 27 July, she spoke with SeafoodSource about best options for dealing with the invader.

SeafoodSource: Your presentation outlined some strategies for dealing with the lionfish invasion. But the National Oceanic and Atmospheric Administration says it is almost impossible to control this species. So how were you able to come up with strategies for doing so?

Fadilah Ali: The difficulty with controlling the lionfish has to do with how they reproduce. When they release eggs it is in a gelatinous mass that has 10,000 eggs that are then taken into the ocean currents. So no matter how well one country would protect their reefs, the eggs would keep reporducing. That is why we need a regional effort. We do not know how many of that 10,000 survive because the way they are transported makes it very difficult.

SeafoodSource: Then what would you say are the most effective methods for dealing with the lionfish?

Ali: The most effective would be through divers because that means there is no by-catch. However, using divers means there is a depth limit to which they can go. In Bonaire, it is a marine park and there is a ban on spears so there is only the Eradicate Lionfish Tool that you can use there. So the tool you use [to tackle the lionfish] depends on the country you are working in and the people doing the removal. Where lionfish are found at great depth you need traps which are most effective. In shallow waters 14 metres and above you find divers are most effective.

SeafoodSource: In your presentation you spoke of “lionfish hunters” as being particularly helpful. Can you please describe these hunters?

Ali: Within Bonaire, they tend to be people that are a little bit older because they have the time to do this or people who are diving enthusiasts. Forty pecent have been Americans. They are not necessarily diving professionals but they have considerable diving experience, as much as between 500 to 2000 hours of diving.

SeafoodSource: Can you say what impact these lionfish hunters have had on the lionfish population? Please give us some numbers.

Ali: The thing about using pure numbers is that this will only be in terms of where you can see. When I first got to Bonaire in 2010, you would see lionfish in high numbers. In a single one-hour dive there would be 30 to 40 lionfish. Now you are lucky to even see one. We do not know if they have gone much deeper. We have had reports by divers on submarines going down to 300 metres that they are seeing lionfish there. We are seeing a difference in the shallow waters but we don't know if we have actually reduced the population or just causing them to go deeper.

SeafoodSource: So going forward, what do you think are the best options for reducing this pest?

Ali: The best way would be developing markets for the end users of lion fish as a meat, using it to make jewelry—these earrings that I am wearing are using the lionfish spine—and developing a market for all sizes of lionfish. The large lionfish are platefish, small lionfish can be used as sausages or deepfried. You can use the spines to make toothpicks and use the head and bones to make a stock for soup. Creating monetary value from the lionfish would encourage people to remove it from our waters.

 

Lionfish illustration credit: Tanya Hart (Flickr/Creative Commons)