What to do with an invasive fish? Make leather | NOVA

It looks like an ordinary leather wallet, neatly sewn, with a slight sheen. “It looks like leather, it smells like leather,” says Aarav Chavda, CEO and co-founder of Inversa Leathers. Twist or bend it, and you might notice it’s “wickedly” strong, thanks to a unique fiber structure. Take a closer look and you might spot the delicate network of ridges that once held the scales in place. But it’s not made of lizard skin. And it’s definitely not cowhide. It’s lionfish.

“We are creating leather from this horrible invasive species,” says Chavda. Inversa’s work is an attempt to resolve an ecological crisis, albeit in unexpected ways. Or, as Chavda puts it, “Wait what, how does a purse save coral reefs?”

Lionfish are unlike anything else on the reef, with striking red-brown zebra stripes and huge venomous spines fanning out around them. Native to the Indo-Pacific region and the Red Sea, they have long been popular in home aquariums. But in the 1980s, a few individuals escaped or were released off the coast of Florida.

Far from the creatures that normally control their populations, these invasive lionfish have become voracious top predators: one study found that lionfish can kill 79% of juvenile fish on a reef in just five weeks. And since many of these fish eat algae on corals, their disappearance can trigger a domino effect that also kills reefs. In recent decades, the fast-breeding lionfish has spread along the Atlantic coast and into the Caribbean with shocking speed. Today, introduced through the Suez Canal, they even invade the Mediterranean.

Watch: Ocean Invaders

Fishing may seem like an obvious solution, but traps and lines don’t fool the lionfish. The best way to eliminate them from an area is to hunt underwater. So to stop this underwater catastrophe, coastal communities are trying to give divers a reason to come out and catch them. Some hold lionfish derbies with cash prizes. Local restaurants have started preparing lionfish meat in dishes like ceviche and fish tacos. Artisans make earrings with the fearsome spines of the fish. And in 2020, Chavda and fellow diver COO Roland Salatino founded Inversa. Now they pay solo hunters and fishing collectives in a dozen Caribbean and Mediterranean countries to harvest the fish for their skins.

Starting with a few divers, Inversa now works with thousands of divers, promising reliable and prompt payment for their catches and teaching them how to manage the risk of a sting, which is painful but not deadly. Sometimes that means the company sponsoring its own lionfish derbies; other times it means working with local governments to secure exceptions to preservation laws. (“There’s a really good reason why people aren’t generally allowed to hunt on coral reefs,” Chavda says.)

Given how quickly the invasive lionfish can take over a new reef, random, large-scale hunting tends not to make a difference, says Salatino, comparing it to “weeding every fortieth weed”. Instead, Inversa encourages the communities it works with to focus on what it calls “management zones,” which divers can return to and comb through again and again.

“There is a restocking rate,” adds Chavda. “You take them off on Monday and then you have to come back in two or three months.”

A single hunter can trap 15 fish on a slow day or 70 if he finds a particularly hot spot for lionfish. Inversa picks up the catch weekly from the Nassau and South Florida docks. At a processing center in Tampa, an employee skins the fish by hand, carefully removing the poisonous spines. The meat is destined for restaurants and the skin is shipped to Inversa’s tanning facilities in Ohio. Everything else is ground for fish oil or bait.

A piece of lionfish leather from Inversa. Image courtesy of Inversa Leathers

In Ohio, lionfish skins undergo an intricate 52-step tanning process. They are bathed and re-bathed in various solutions, with names like “scaling” and “stripping”, which manipulate their pH level. This process allows tanners to target the fibers of fish skin, open up the collagen network that holds the skin together, help a chemical “tanning agent” bind to this network, and then lock it to new. The result is that “the overall structure of the skin is strengthened,” explains Salatino. “Oils and fats and all those lumps are removed. All you’re left with is the strong, reinforced leather. The end result: handbags, wallets, belts and sneakers with that distinctive scaly pattern, sold by exotic leather companies that might otherwise focus on shark, bison or stingray.

From the start, Inversa leathers were in high demand. “We’ve never had any arrears,” says Chavda. They bought hundreds of fish a week last year from individual hunters and fishing collectives, with the largest two-day haul exceeding 7,000 fish. And they recently purchased new tanning drums that can handle seven times their previous maximum material.

These drums won’t just contain lionfish. Inversa has recently begun to expand to other invasive species, including pythons that have a literal hold on the Florida Everglades. “They kill 99% of small mammal life,” says Chavda. “Before, there were otters, squirrels, rabbits, songbirds, alligators.” The irony, he points out, is that python skin leather is actually in demand in parts of the world where the snakes are native and near-threatened. He and Salatino maintain a running list of some 4,000 invasive species that Inversa may one day turn into products. Much like lionfish, “We’d like to stop using python where they’re becoming more and more endangered, and instead use them in areas where they’re really decimating our lives,” says Salatino. One handbag at a time.

Receive emails about upcoming NOVA programs and related content, as well as reports on current events through a science lens.

Previous LAists visits: the corner of Whitsett and Burbank, for Bengali fish and lentil head curry, exceptionally soft pitas and Pittsburgh-style pizzas
Next In Britain's inflation crisis, healthy diets are a casualty