Review: Large-sized fish appeared in the Three Gorges Dam water area, and a large number of creatures called "water tigers" have raised public concern. Experts have stated: try to avoid human intervention as much as possible.

Overview

In summer 2023, netizens captured a stunning aerial shot in the Three Gorges Dam area: on the wide river surface, countless bighead carp and snakehead fish gather, play, and swim freely. Many snakehead fish exceed 2 meters in length, with some large individuals reaching up to 3.2 meters. Their thick bodies dart back and forth across the water, creating a spectacular scene.

Within the dam area, the snakehead fish population is comparable to that of bighead carp. This sight has sparked concern among many netizens. Known as the “water tiger,” snakehead fish are considered dominant predators in freshwater ecosystems. Some worry that their numbers are too high, potentially squeezing out other fish species and disrupting water balance. However, experts in the field have made it clear: there’s no need for human intervention; everything should be allowed to develop naturally.

The Water King — The True Face of Snakehead Fish

Snakehead fish are large freshwater fish, also nicknamed “water tiger,” and called “pole fish” or “copper-headed arrow.” They have sharp, pointed snouts, a slender, semi-cylindrical body, fine scales, a brown-gray back, and a silvery-white belly. Their dorsal and tail fins are dark gray, while other fins and cheek areas are pale yellow, making them highly recognizable.

Snakehead fish grow rapidly, reaching sexual maturity at 3 to 4 years old, and continue to grow afterward. Adult snakehead fish typically exceed 2 meters in length and weigh over 100 jin (about 50 kg), with some large specimens approaching 200 jin (around 100 kg). Recent fishery monitoring reports show that a giant snakehead caught in Dajin Lake, Fujian, measured 1.97 meters and weighed 164 jin. The largest snakehead fish monitored in the Three Gorges Dam area recently reached 3.2 meters in length and 198 jin in weight, setting a regional record.

Snakehead fish are widely distributed across northern and southern freshwater waters in China, being semi-migratory. From April to June each year, they migrate in groups from downstream river sections to fast-flowing waters to spawn. The large congregation of snakehead fish in the Three Gorges Dam area is a typical sign of their spawning season.

After hatching, juvenile fish swim to lakes and shallow areas connected to the water system to feed and develop. By late autumn and early winter, as water temperatures drop, they migrate to deeper parts of the main stream to overwinter, completing their annual life cycle.

Snakehead fish are swift swimmers and aggressive predators. Their large size and sharp teeth make them nearly invincible in freshwater, and other fish fear them greatly. They are often called the “dual overlords” of freshwater, alongside the mandarin fish.

They prefer to hunt in the upper water layers, with a varied diet that includes both animal and plant matter. Despite their small eyes and relatively weak eyesight, they have a strong hunting instinct. Once they spot prey, they chase and bite fiercely, making it difficult for prey to escape. Even frogs and small waterbirds near the shore can become targets.

This predatory nature makes snakehead fish one of the most hated species among aquaculture farmers. If they accidentally enter a pond, they behave like dragons entering the sea—eating all kinds of fish and shrimp, causing significant losses.

Although fierce and known as the “water king,” snakehead fish can only be caught with nets. They grow quickly, are large, and have tender, nutritious meat, making them a valuable economic fish. By March 2026, China’s Hubei, Jiangsu, Fujian, and other regions have successfully scaled up artificial breeding of snakehead fish, meeting market demand and reducing reliance on wild populations.

Yangtze River Fishery Ban

A nearly 200-jin adult snakehead fish consumes about 40 jin of fish and shrimp daily. The large gathering of snakehead fish in the Three Gorges Dam area has led many netizens to worry that they might overconsume other fish species, damaging the Yangtze River ecosystem.

As a carnivorous species, if snakehead populations become too large, they will heavily prey on herbivorous fish, causing their numbers to plummet. This can lead to overgrowth of aquatic plants, eutrophication of water bodies, and ultimately ecological imbalance. Therefore, many suggest that the population of snakehead fish in the Yangtze should be controlled through human intervention to maintain ecological stability.

However, experts have clarified that there’s no need for excessive worry or artificial control. The large number of snakehead fish and bighead carp in the Three Gorges Dam area is actually a positive sign of the effectiveness of the Yangtze River fishing ban policy and a direct reflection of ecological recovery.

Decades of overfishing, pollution, and water conservancy projects have severely damaged the Yangtze’s ecosystem. Monitoring data shows that in 2018, the biological integrity index of the Yangtze reached its lowest point ever, approaching a “fishless” level, with many rare species near extinction and the ecosystem on the brink of collapse.

To restore the Yangtze’s ecology and biodiversity, China officially launched a ten-year fishing ban in 2021. Over five years into the policy, results have exceeded expectations: populations of various aquatic species have increased significantly, biodiversity is gradually recovering, and the large congregation of snakehead fish and bighead carp in the Three Gorges Dam area is a vivid proof of these achievements.

Experts emphasize that, although snakehead fish are predators that may impact some herbivorous fish populations, this is a natural ecological process. Human interference should be minimal; excessive intervention could disrupt ecological balance.

Let Nature Take Its Course

The large number of snakehead fish in the Three Gorges Dam area does not mean they are overpopulated throughout the entire Yangtze River basin. Summer is their spawning season, with suitable water flow and temperature conditions making the dam area an ideal spawning ground. After spawning, they disperse into various parts of the Yangtze, and their numbers will naturally decline.

Even if snakehead populations temporarily surge, ecological mechanisms will regulate their numbers. Despite their near absence of natural enemies in freshwater, they are still part of the food chain and are naturally constrained. If their numbers become too large, they will prey heavily on other fish, and limited food resources will lead to some being starved out, causing the population to decrease naturally.

The populations of snakehead and other fish species will gradually reach a stable balance through ecological cycles, without the need for human intervention.

In natural ecosystems, both predatory and herbivorous fish play irreplaceable roles. Snakehead fish help control herbivorous fish populations, preventing overgrazing of aquatic plants, which can cause oxygen depletion, water quality deterioration, and threaten other aquatic life.

For humans, the best approach to the Yangtze’s ecological recovery is to let nature take its course. The Yangtze is a complex, interconnected ecosystem where species coexist and depend on each other, forming a stable balance through long-term competition and symbiosis.

If any species’ population becomes abnormal and causes significant ecological harm, experts will monitor and take scientific, appropriate measures to regulate it—no need for public reminders or excessive concern.

Conclusion

Currently, there’s no need to worry that the “water tigers” in the Three Gorges Dam area will damage the Yangtze ecosystem, nor is there a need for human intervention in their populations. Natural ecosystems are intricate and delicate, with each species playing a vital role. Interfering prematurely could break this natural balance and trigger chain reactions. With the continued implementation of the Yangtze fishing ban, we expect to see more rare aquatic species emerge in the future, witnessing the river’s ecological renewal and vitality.

It’s worth noting that, although the ten-year fishing ban is in effect, recreational fishing with a single rod is not prohibited outside core protected zones. If you want to taste the delicious meat of snakehead fish, you might try fishing for them. However, snakehead fish are very strong and swift, making fishing challenging and requiring some skill and experience to successfully land this “water tiger.”