NOVA: Ocean Invaders | KPBS Public Media

Premieres Wednesday October 26, 2022 at 9 p.m. and Sunday October 30 at 2 p.m. on KPBS TV + October 30 at 9 p.m. on KPBS 2 / PBS Video App

NOVA “Ocean Invaders” explores the fascinating rise of invasive species in a globalized world where human activity has become an increasingly powerful evolutionary force. This dives deep into understanding a massively destructive species that has taken our oceans by storm – the lionfish. Native to the South Pacific and Indian Oceans and long prized in home aquariums, the lionfish invaded the Atlantic and is now one of the most successful invasive species in the ocean, wreaking havoc in waters around the world. entire.

The film follows ocean explorer Danni Washington on his journey to answer essential questions: what made lionfish so successful at invading? Why are they doing so much damage? Where do they come from? What, if anything, can we do about them? Danni consults with experts, including marine biologists Carole Baldwin and Luke Tornabene, and endangered species expert Frank Mazzotti, who each share their unique expertise.

NOVA: Ocean Invaders: Preview

With striking striped bodies and a range of 18 poisonous spines, lionfish are as spectacular as they are dangerous. The lionfish is native to all of the Indo-Pacific oceans, where it has a number of natural predators. In these areas, the lionfish is considered a beautiful ornamental species, not an out-of-place nuisance. While the lionfish’s beauty is what helped make it popular in home aquariums around the world, most scientists believe it’s also what ultimately led to the Atlantic invasion.

The prevailing theory is that in the 1980s lionfish living in home aquariums were released off the coast of Florida. Over the following decades, they began to proliferate along the Atlantic and Caribbean coast. They are now widespread from North America to Brazil – there are even records of lionfish in the Mediterranean, introduced separately via the Suez Canal. Shorting geographical barriers between species is nothing new – for millennia, humans have managed to move many animals to opposite ends of the earth. So what sets the lionfish apart, allowing it to proliferate so quickly in its new territory?

The lionfish has a series of characteristics that make it a particularly effective invasive species. Their appetites are seemingly endless – they eat over 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, the female lionfish can produce millions of eggs throughout the year. And perhaps most importantly – in their non-native habitat there are no animals that are used to seeing them as food. So, without predators to control them, lionfish have an unfair advantage.

But why is an animal thriving in new territory a problem? “Ocean Invaders” takes a step back from the lionfish to investigate the sometimes confusing way in which species are referred to as “invasive”. Looking more closely at the terrestrial invasions of species like the terrifying northern giant hornet in Washington State, European bees in North America, and even pet cats, it becomes clear that the threshold for earning the label is boils down, in large part, to the extent to which a species is disrupting ecosystems at that particular time. And to prevent an invasive species from irreparably altering the balance of an ecosystem, early detection and a rapid response are essential. Once an invasive species has established itself, the amount of money and resources needed to eradicate it are too expensive.

Today, lionfish are well established in many parts of the Atlantic and have a significant impact on the marine food web of these ecosystems. In some places lionfish kill up to 80% of small young fish. In some Atlantic waters, they even represent almost 40% of the total predator biomass, whereas not so long ago they represented 0%. In parts of the Atlantic, the increased abundance of lionfish has coincided with a significant decline in many different prey fish.

Many of these species play a crucial role in the survival of corals. For example, if lionfish continue to overconsume important players that control algae growth, reefs could suffocate. From fishing to tourism, the lives of countless western Atlantic coastal communities that depend on coral reefs could be at risk. These threats are what drive local divers to do something about the invaders from the Atlantic.

In addition to trapping and hunting lionfish to manage populations, researchers are also capturing lionfish from deeper waters, hoping to study them to decipher their invasive habits and better understand their behavior. For example, scientists can examine their stomach contents to gain insight into their eating habits. A recent exploration of this showed that, based on what they ate, the lionfish are likely wreaking havoc in even deeper waters than expected. This is just the beginning of the research and it has the potential to unlock many more questions.

“Ocean Invaders” explores creative methods to motivate locals to manage the lionfish population, as awareness of the problem grows. Enticing invaders to fish creates dual benefits – businesses that revolve around the invasive lionfish not only support the ecosystem, but local economies as well. People are getting into lionfish hunting for side jobs, and it has even been gamified to create lionfish hunting tournaments.

The invasive lionfish is becoming an increasingly popular local dish, being introduced to the cuisines of the Caribbean, Florida Keys and Gulf Coast. From ceviche to whole fried, fish can be used to create island favorites, sustainably. People are even finding ways to use every part of the lionfish’s body, beyond just eating. The film shows how artisans repurpose the lionfish’s ornate fins to create jewelry, shoes and other products.

As lionfish upset the balance of biodiversity along the Atlantic coast, it might be tempting to let nature take its course and see how natural selection unfolds – but at what cost? We risk losing native species that play an essential role in their environment. When we disrupt ecosystems so quickly, we plunge headlong into uncharted waters.

Watch at your own pace:

Premieres Wednesday, October 26, 2022 at 9 p.m. ET/8C on PBS. The film will also be available to stream online at, and through the PBS Video app.


A NOVA production by Orange Frame Productions for GBH. Hosted and narrated by Danni Washington. Written, produced and directed by Jeff Boedeker. NOVA’s lead producer is Caitlin Saks. NOVA’s executive producers are Julia Cort and Chris Schmidt. NOVA is a GBH production.

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