The lionfish is an undeniable head-turner. With its vibrant - and venomous - spines radiating from its head like a lion’s mane, its voracious appetite and incredible resilience makes it the perfect hunter, a king in the aquatic jungle. However, for the millions living within the Caribbean Sea, Gulf of Mexico and the Western Atlantic, they are in the wrong jungle.
For the past 3 decades, the lionfish have made these waters their home, and with no natural predator, they have had a devastating impact on native fish populations. Experts widely agree that total eradication is impossible, but local communities are fighting back in innovative ways, as Keiko Ashida Tao, Environmental Specialist for the World Bank, explains.
Question: How has the lionfish impacted the marine ecosystem?
Keiko Ashida Tao: After initial sightings in the mid-1980s off the coast of Florida, lionfish populations have now spread along over 5,000 miles of the east coast from as far north as Rhode Island, all the way down to Sao Paulo in Brazil. And the impact has been devastating, for two main reasons:
- It is an indiscriminate hunter and preys on over 60 native species, more specifically the juvenile populations. And these eating sprees are horrifyingly effective - the lionfish can reduce native fish population by an average of 79% over a 5-week period, hunting in groups and continuing to feed until all the prey in one area have been wiped out.
- The lionfish is built to survive. Not only does the species reproduce at an alarming rate, with multiple spawnings each month, year round, lionfish can also survive for up to three months without eating, live at depths of up to 1000ft (300m) as well in low-saline waters. Combine this adaptability with rising sea temperatures and global warming could create yet more favorable habitat conditions, spreading the lionfish yet further across the east coast.
Q: What is the wider impact of this invasion?
K: Well, of course, the impact of the lionfish invasion is not limited to the native species which now make up their prey. Rather, the survival of the marine ecosystems within the affected area, and the local economies which depend on them, are in question.
Let’s take Belize as an example. Here, the Mesoamerican Barrier Reef, (the second longest barrier reef in the world after the Great Barrier Reef), provides critical natural resources and environmental services to the local economy. In fact, it’s estimated that these services (fishing, tourism, shoreline protection) provided by the reef, and the mangroves which surround it, contribute between 15-22% of annual GDP in Belize. In dollar terms, that’s between US$ 395-559 million a year.
But, the reef is in a bad shape, and around two-thirds is reported to be in poor to critical condition, predominantly due to the impacts of climate change (bleaching, increased acidification, higher sea temperatures etc) and anthropogenic stressors such as agricultural run-off, sedimentation and overfishing. For the reef to recover, plentiful sea life in and around the coral reefs is key. In fact, a study on corals in the Caribbean discovered that when “grazer” populations are abundant (parrotfish and surgeonfish for example), the reefs maintain a good balance of algae and are healthy, therefore are more likely to recover from hurricane and bleaching damages than where grazer numbers were depleted. Consequently, controlling the population of invasive lionfish is critical to addressing ecological imbalances and regaining a healthy reef that nourishes and harbors numerous marine species