The PBS science series NOVA will premiere the one-hour documentary “Ocean Invaders” this week, exploring the rise of invasive species in a globalized world where human activity has become an increasingly powerful evolutionary force, specifically the lionfish.
Native to the South Pacific and Indian Oceans and long prized in home aquariums, lionfish have invaded the Atlantic, and are now one of the ocean’s most successful invasive species, wreaking havoc in waters across the globe.
The program follows ocean explorer Danni Washington on her journey to answer essential questions like: What has made lionfish so successful at invading? Why are they doing so much damage? Where did they come from? What, if anything, can we do about them? Washington talks to experts including marine biologists Carole Baldwin and Luke Tornabene, as well endangered species expert Frank Mazzotti.
The prevailing theory for how they came to infest the Atlantic is that in the 1980s, lionfish living in home aquariums were released off the coast of Florida. Over the next few decades, they began proliferating up and down the Atlantic coast and Caribbean. They’re now widespread from North America all the way down to Brazil — there are even records of lionfish in the Mediterranean, introduced separately via the Suez Canal.
Short-circuiting the geographic barriers between species is not new — for millennia, humans have managed to move plenty of animals to opposite ends of the earth. So what sets lionfish apart, allowing them to proliferate so rapidly in their new territory?
Lionfish have a suite of characteristics that make them a particularly successful invasive species, according to NOVA. Their appetite is seemingly endless — they eat more than 100 different marine species, and can devour 90% of their body weight in a day. While most native fish only reproduce for a few months, female lionfish can produce millions of eggs over the entire year. And perhaps most importantly: In their non-native habitat, there aren’t any animals who are used to seeing them as food. So without predators to keep them in check, lionfish have an unfair advantage.
But why is an animal thriving in a new territory a problem? “Ocean Invaders” takes a step back from lionfish to investigate the sometimes-confusing way that species are labeled “invasive.” By taking a closer look at terrestrial invasions from species like the Northern Giant Hornet in Washington state, European honeybees in North America and even pet cats, it becomes clear that the threshold for earning the label comes down, in large part, to the extent a species is disrupting ecosystems at this moment in time. And to avoid having an invasive species irreparably shift the balance of an ecosystem, early detection and rapid response is key. Once an invasive species becomes established, the amount of money and resources needed to eradicate it are too costly.
The show explores creative methods for motivating locals to manage the lionfish population, as awareness of the issue builds. Incentivising fishing the invaders creates benefits that are twofold — businesses that revolve around invasive lionfish not only support the ecosystem, but local economies too. People are taking up lionfish hunting for side jobs, and it’s even been gamified to create lionfish hunting tournaments.
Invasive lionfish are becoming an increasingly popular local dish, being introduced to cuisines across the Caribbean, Florida Keys and Gulf Coast. From ceviche to fried whole, the fish can be used to create some island favorites, sustainably. People are even finding ways to use every part of the lionfish’s body — beyond just for eating. The film highlights how craftspeople repurpose the fish’s ornate fins to create jewelry, shoes and other products.
According to NOVA:
“As lionfish disrupt the balance of biodiversity along the Atlantic coast, it might be tempting to let nature run its course and see how natural selection pans out — but at what cost? We risk losing native species that play critical roles in their environments. When we disrupt ecosystems so rapidly, we dive headfirst into uncharted waters.”
(Featured Image credit: © Laura Dts / Shutterstock via NOVA/PBS)