“Poisonous lionfish may invade Med” ran headlines in June this year, while marine biologists mumbled: “they’re venomous, not poisonous”.

Irrespective of their palatability (they’re actually delicious), lionfish have reached the Mediterranean, and the fears of conservationists and fishermen alike are set to come true. The fish, a highly opportunistic predator, is set to further impact an already threatened ecology, replicating the rapid spread of their cousins across the eastern Atlantic, from the Carolinas to Venezuela.



The International Union on the Conservation of Nature (IUCN), the global body that maintains the increasingly concerning red list of endangered species has confirmed that lionfish are present in the Mediterranean. Some would argue that this is not news, with sightings of the fish reported since the 1990s. However, recent observations around Cyprus have shown multiple individuals and breeding pairs. These are no longer isolated sightings.

Hunting lionfish in waters off the Windward Islands, where divers used a multiple-barbed harpoon to spear the fish. Photograph: Richard Aspinall

Common lionfish and the similar red lionfish are now found in the eastern Atlantic, far from their native Indo-Pacific. One suggested explanation is that when Hurricane Andrew made landfall in 1992, a beachside aquarium in Florida containing half a dozen fish was smashed. The tale goes that divers later saw the group, and thus the story became accepted. There is though, a credible account of a lionfish spotted in Floridian waters in 1985, well before the presumed ancestors of the “invasion” ever found freedom. Release from home aquaria is now accepted as at least one point of introduction, with genetic evidence supporting the “multiple release” theory, along with the fact that there are two similar but distinct species involved.

In the Indo-Pacific, lionfish are controlled by predators; groupers and, on occasion, sharks take them at various stages of their growth. Elsewhere, however, predators seem not to recognise them as prey and ignore them, allowing lionfish numbers to grow at a startling rate at the expense of local fish stocks.

The route lionfish have taken to the Med seems straightforward; they have simply colonised through the Suez Canal from the Red Sea, and can be added to the growing list of Lessepsian species (named after Guy de Lesseps, the French engineer who oversaw the construction of the Canal). Whether fish released from aquaria are also present in the Mediterranean is unclear, though as sea temperatures rise, the survival of tropical species released by accident or design is more likely.

Some authorities suggest the Med, a less uniform environment than the Caribbean, will be harder for the fish to colonise, but given the lionfish’s prodigious breeding rate (a female can produce two million eggs a year), it is impossible to rule out the possibility of colonisation from North Africa even to the cooler shores of Europe.

The lionfish has a prodigious breeding rate - a female can produce two million eggs a year. Photograph: Richard Aspinall

If the lionfish invasion across the Atlantic is anything to go by, their spread will be rapid and uncontrollable - and there isn’t a “magic bullet” that can remove the fish from across their new range. Time will tell, of course; we’ll know eventually whether native predators add lionfish to their diet. Meanwhile, more immediate methods are being employed by the diving community and are receiving some support from state and national agencies. The Florida Fish and Wildlife Conservation Commission, for example, regularly sponsors and promotes the culls, derbies and hunts that are organised by dive centres and diving organisations. In other locales, where resources and government interest may be reduced, individual dive centres have decided to take their own action to protect the fish life on their local reefs. One day, we might see similar events in the Med, and possibly lionfish on the menu in Mediterranean restaurants, especially given that it’s a region where spearfishing is considered a sport.

Catching lionfish is not that hard with the correct gear and a little experience. Variations on the theme of harpoons and spear guns are used. Lionfish are poor swimmers and can usually be approached: they’re relying on their camouflage and spines to deter unwanted attention.

I photographed a hunting session in the Windward Islands, where divers used a multiple-barbed harpoon to spear the fish. Some hunters then use another harpoon, ensuring it dies quickly and to allow the diver to manipulate the fish. Even though the fish is dead, its venom is not and if the spines puncture flesh, the pressure causes venom to move from glands along the spine, via ducts, into the victim’s flesh. Some hunters remove the spines underwater; others trim the fish on land.

Catching lionfish is not that hard, with the correct gear (usually a harpoon or spear gun) and a little experience. Photograph: Richard Aspinall

Lionfish envenomation has been described as excruciatingly painful, though deaths are rare. Being a complex protein the venom is rapidly denatured and victims are encouraged to apply heat to the affected area, whether via hot water or a hair drier. Needless to say, caution should be exercised as otherwise scalds and burns may be more problematic than the venom. Urine or vinegar will have no effect, other than to add further unpleasant memories.

Lionfish behaviour may be shifting though, especially where they are hunted. Anecdotal evidence from some regions suggests they are altering their behaviour to the times dive centres operate, or moving to deeper waters. In their native range, lionfish will sometimes use divers as cover when hunting, benefitting from the confusion created amongst smaller prey species.

Lionfish hunting will not offer a complete solution, as only a fraction of the world’s reefs are visited by divers, making eradication unlikely. The hope is that local fauna will adapt, though it’s a long shot, particularly in the Med, where overfishing has reduced the population of potential predators to negligible levels.

Some hunters remove the spines underwater, as even if the fish is dead, its venom is not. If the spines puncture flesh, the pressure causes venom to move from glands along the spine, via ducts, into the victim’s flesh. Photograph: Richard Aspinall

So far, the only tactic that has had any noticeable (if small) impact on local lionfish populations has been that of encouraging the catching them for human consumption. Though control efforts face that most tricksy of problems: public perception. There are many fishing communities that are convinced lionfish are poisonous, leaving far more ecologically valuable fish, such as grouper and parrotfish, still on the catch list. If the Med is to face a full-scale lionfish invasion, concerned fishing communities and restaurateurs need to be reminded that the fish are not ppoisaonous and encouraged to add it to their menus and catch lists.

It’s an odd irony that so many stories involving marine conservation return to over-consumption of fish, but this is a story in which eating the fish in question could provide a happy(ish) ending. Luckily, lionfish are thoroughly delicious, especially when cooked as soon as possible after landing.

Personally I’d pan fry them with butter and a little thyme and serve with a crisp white.

Richard Aspinall is a freelance writer and photographer who lives in the Scottish Borders. After working in conservation and land management in the public sector, Richard now spends as much time as possible with his underwater camera. He tweets at @triggerfish_com.