Teach Predators to Eat Invaders

Introduction

While there are various ways to combat invasive species, there are still disagreements about how to handle them humanely, efficiently, and despite a lack of people to help in the battle for our ecosystems.

One of the more promising-looking solutions is to each wild predators how to hunt and consume the invasive species which are increasingly taking over their habitats, even eating the predator's food.

This solution effectively turns "problem" species into edible opportunities for these predators, who are at increasing risk of starvation if the invaders continue to spread unchallenged.

Identify Invasives: Apps & Guides

The following include apps, local/regional guides, and some of the sites or apps also double as a way to report invasives, which may be important for scientists to track their progress through an area, or alert trained people who can come and safely handle the species in question. 

Ocean Predators

Fish

Lionfish

Lionfish are invading the Caribbean and coast of Florida, but a recent discovery found that lionfish can tolerate fresh water too, meaning they may also pose a risk to freshwater ecosystems over time.

So far the species who have been found to tolerate eating lionfish include:

Feeding Lionfish to Sharks

1:33 minute video

Teaching Eels to Eat Invasive Lionfish

"A divemaster off the coast of St. Kitts spears lionfish (an invasive species in the Caribbean) and feeds them to sharks to teach them to seek out the fish as prey. The lionfish invasion is considered to be one of the most serious recent threats to Caribbean and Florida coral reef ecosystems. Culling by marine protection agencies and volunteer divers is an important element of control efforts. Adult lionfish have few identified natural predators, likely from the effectiveness of their venomous spines. Moray eels, bluespotted cornetfish, and large groupers have been observed preying on lionfish. During our diving at St. Kitts, we witnessed that sharks are also capable of preying on lionfish with no ill effects from their spines"

Teaching Grouper How to Eat a Lion Fish

Barracuda Eats Lionfish

Lionfish Capture Options for Feeding Wildlife

If you want to teach a wild predator to eat something, first you need to capture their prey, this can be done with harpoons or traps, then the fish can be wiggled in front of the predator to catch their interest. Helping predators consume these fish helps them learn to associate their bizarre (almost coral-like shape) with food, and this can encourage them to actively seek out these invaders as prey in the future.

Harpoon Fishing

Lionfish Clean Up

You can see the specialized harpoons and containers used to catch invasive lionfish.

Traps for Lionfish

Traps Being Tested to Control Destructive Lionfish

Shellfish

Pacific Oysters 

According to this paper, "at present other natural regulatory mechanisms controlling the population development of M. gigas are absent or low due to lack of natural predators. The most common invertebrate shellfish predators in the Wadden Sea and Dutch estuaries are the brown shrimp Crangon crangon, the shore crab Carcinus maenas and the common starfish Asterias rubens (Troost, 2010). No doubt these invertebrates predate on spat and juvenile Pacific oyster specimens, but not so much in lower saline habitats where the Pacific oyster still thrives, but the predators face osmotic challenges. To our knowledge, thorough documentation on the significance of predation is still lacking. In the Wadden Sea herring gulls, Larus argentatus, and oyster catchers, Haematopus ostralegus, are the only reported bird species predating on M. gigas (Cadee, 2008a, Cadee, 2008b). Moreover, the colonization by Pacific oysters certainly does not improve bird biodiversity but shows negative impacts mostly for three species: Oystercatcher, Common Gull, and Knot (Waser et al., 2016). In the Wadden Sea ecosystem, the Pacific oyster is associated with five invasive and native macro parasite species thoroughly discussed by Goedknegt (2017). However, a more serious situation emerges concerning disease outbreaks among Pacific oysters. Recently an ostreid herpesvirus microvariant (OsHV-1 μ var. disease) was detected in culture installations as well as in wild populations in France, Sweden, Norway, USA, and Australia causing mass mortality among the oysters (e.g., Mortensen et al., 2016; King et al., 2019). - Too Late for Regulatory Management on Pacific Oysters in European Coastal Waters? 

Organizations

Europe

North America

USA

Maps

International


Biocontrol Solutions for Invasives

Europe

Related Topics

Biomes of Note

The following places may be at particular risk of invasive infiltration, acting as vectors, but also providing native species with the ability to maintain health populations which can help control invasives.