What Is An Underwater Forest?

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As an evolved species, we humans believe we have an elevated understanding of this planet. We also believe inhabitable land exists only above the water. As an extension of this logic, all flora & fauna, trees and especially whole forests should exist solely on such inhabitable land. However, all it takes is one natural calamity like a flood, an earthquake or even a hurricane to shake up, figuratively and literally, our preconceived ideas of the global landscape. An underwater forest is such an example. In this blog, we will explore this “natural” wonder.

What Is an Underwater Forest?

An underwater forest is essentially an entire forest landscape that is completely immersed in a large water body like a lake, sea or ocean. For this reason, it is also referred to as a “submerged forest”. You can think of it as historic remains of (potentially thriving) plant life.

How is a Forest Caused Underwater?

Scientists believe it is rising sea levels that are the primary cause of underwater forests. However, this does not happen gradually. Instead, it is often a sudden development due to a geological event which causes a large flood or marine transgression. The transgression also causes the shoreline to rise suddenly and dramatically, which again leads to flooding.

If the flood is caused by a typical storm, the water level gets back to normal after a few days/ weeks. However, if it is caused by a geological transgression, the water stays at a high level, thus drowning the entire forest. Now, it becomes an underwater forest.

Landslides and the Effect on Rivers

Consider a river that is bound by a man-made damn. In case of a large landslide, if the dam blocks the valleys of the river, rainwater can collect in these valleys to form a lake. This can form into an underwater forest, and the land that existed prior to the landslide becomes submerged within the lake.

A Natural Time Capsule

Regardless of the manner in which they are formed, underwater forests are a rarity, and they are especially fascinating to the geological and archaeological communities. The forests can be considered frozen in time as they are often found preserved close to their original state. Scientists study these forests to understand the conditions of historic times.

Here, you will be surprised to know that it is the lack of oxygen, which unintentionally causes this preservation. This can happen in deep ocean water–which is incidentally warmer than normal water–leading to de-oxygenation. As a result, the pace of degeneration of the trees, plants, and wood in the underwater forest is significantly reduced. This allows the forest to stay alive, despite being submerged in water for thousands of years.

How Do Scientists Find and Study Underwater Forests?

An underwater forest can be considered an accident of a natural event or calamity. It is this nature, which also reveals the forest to humanity. This can happen during a large low tide where the water body’s reduced level exposes the underlying underwater forest. It can also happen during a hurricane where remnants of the forest are raised within the water body. Finally, it can happen purely by accident, when it is discovered by a fisherman or deep-sea diver. In recent times, modern technology has also enabled marine laboratories to predict areas in the ocean that can possibly contain underwater forests and plant life (especially using sonar machines).

The Scientific Study of Underwater Forests

As you can imagine, there are several challenges that a scientist can face in his deeper study of the submerged forest. First, the forests can be tens of thousands of years old, naturally preserved due to the low oxygen content within the deeper waters. Hence, this needs to be maintained so the scientist’s studies do not inadvertently accelerate the forest’s degeneration. Samples of the forest’s (sea) floor are collected for scientific study using a vibracore machine. This machine can penetrate up to 9 inches below the sea floor level in order to collect samples of the sediment. Samples of the wood from the forest trees are also collected for further study.

For a scientist, the most intriguing aspect of a discovered underwater forest would be its age. For this, a process of radiocarbon dating is used. This process can reveal the forest’s age, up to fifty thousand years. The closer it is to the limit, the less accurate is the predicted age.

Depending on the availability, the pollen grains collected from the sea floor can also provide additional details about the underwater forest. With this, scientists will be able to determine additional details like the reason for the submersion, the type of forest it originally was (like coastal, tropical, etc.), the kind of life that thrived within the forest (like freshwater plants, terrestrial plants, etc.), and accordingly make significant observations on the changing climate conditions that have occurred since the forest was submerged.

Most Famous Underwater Forests in the World

Underwater forests can be a haunting tribute to an earlier era in time. It is for this reason that they always generate high interest among the scientific community. The four most significant underwater forest discoveries are captured below.

Alabama’s coastal underwater forest, USA

This underwater forest was recently discovered in 2012 and is expected to be the oldest submerged forest found so far. In fact, a radiocarbon dating process indicates it to be “carbon dead”–meaning that it is over fifty thousand years old (Carbon dating can determine an age up to fifty thousand years old). This forest also reveals that the sea level has risen over four hundred feet in these past years. While the forest itself is a source of wonder for scientists, its revelation on the effects of climate change is an undeniable warning to humanity.

Lake Bezid, Romania

This lake forms an eerie picture of the past as it encompasses an entire submerged village. In fact, the water’s surface level provides a haunting glimpse of a church surrounded by (dead) trees. As if this is not ghostly enough, the lake’s deeper waters conceal a graveyard of houses! This is because the lake itself was artificially created after a large flood submerged the entire village. To prevent frequent flooding, a dam was created around the water (about twenty-five years ago), leaving the frozen waters of the current lake in place.

Lake Kaindy, Kazakhstan

This is a lake which is indeed one of nature’s wonders. It is measured at a hundred meters long, with a depth of up to thirty meters. However, these dimensions are not what set this lake apart. Its beguiling appeal comes from the fact that this lake is located a massive two thousand meters above sea level. As you may have already guessed, this is anything but normal and was the result of a large earthquake in the year 1911. The lake itself is a result of a landslide during the earthquake, thus forming a natural dam to collect rainwater. This century-old lake is hence a living testament to a submerged (yet thriving) forest. In fact, you can see parts of the underwater forest proudly protruding about the lake’s surface level, as dried tree trunks (The trees itself within the forest are vibrantly alive).

Periyar Lake, India

Lake Periyar is located in the state of Kerala in India. Ironically, the lake itself resulted from a large flood, when the dam surrounding an artificial reservoir of water failed to contain the flood. Here too, you will see tree stumps that were once a part of a thriving (underwater) forest, desolately peek out of the surface waters. The interesting thing to note here is that lake is very much in use as it receives water from the Periyar River (hence its name). Its waters also fill the Vaigai River in the neighboring state of Tamil Nadu.

Lake Volta, Ghana

Imagine if a dam causes flooding which then submerges an entire forest. The underwater forest found within Lake Volta is once such an occurrence. This lake was inadvertently formed in 1965 because of the large flooding caused by the construction of the hydroelectric Volta dam. To understand the level of devastation this dam caused, one has only to look at the haunting numbers. The dam’s construction destroyed over one hundred and twenty surrounding buildings and forced surrounding inhabitants to move with over two hundred thousand animals. That is an entire village and its forest that lay buried within this lake! This lake is now famous for having the largest surface area, and the range of woods that protrude from its surface (The woods from the different trees are buried and preserved within its deep waters).


An underwater forest is a force of nature. To a scientist, it represents a valuable time capsule worthy of a deeper study to understand how the planet has evolved over the ages. However, the recent discoveries also serve as a timely alarm call to humanity, as it is a tangible representation of the adverse effects of climate change. Is humanity ready to wake up? That remains the unanswered question.

Jack Thompson

Jack Thompson, a scuba diving enthusiast from San Diego, has spent over a decade exploring the underwater world across the globe. Sharing his passion through captivating stories and informative articles, Jack aims to inspire others to embark on their own scuba diving adventures and uncover the ocean's hidden treasures. Follow Jack on Twitter, Pinterest, Reddit, and Facebook or email him at Jack@diving-info.com

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