The Underwater Petrified Forest — a new temporary exhibition at the National Museum of Natural History, Sofia

On June 3rd, 2025, in the lobby of the National Museum of Natural History, Sofia, Assoc. Prof. Nikolay Simov (NMNHS) and Assoc. Prof. Lubomir Kenderov (Vice-Dean of Economic Affairs of Faculty of Biology, Sofia University “St. Kliment Ohridski”) opened the exhibition “The Underwater Petrified Forest”, dedicated to the natural phenomenon near Sozopol. Official guests of the opening were the Vice-President of the Bulgarian Academy of Sciences, Prof. Doctor of Historical Sciences Shtelian Shterionov, Prof. Nesho Chipev (IBER-BAS) and Prof. Hristo Pimpirev (Sofia University “St. Kliment Ohridski”).

The exhibition is a result of the work of researchers from the three institutions under the project “Complex ecosystem study of the water area of the natural phenomenon “Underwater Petrified Forest”, Sozopol Bay”, Project No. KP-06-N61/11-15.12.2022, led by Assoc. Prof. Dr. Lubomir Kenderov, financed by the National Science Fund, Ministry of Education and Science of Bulgaria.

Assoc. Prof. Nikolay Simov welcomed the guests on behalf of the National Museum of Natural History, Sofia and noted that “we are talking about a unique natural phenomenon that you will be able to find out more about. In the exhibition you will see a 3D model of a fossil stump from the Underwater Petrified Forest, called “The Crown”, as well as a sample of fossil wood collected for research during the project studies”.

Assoc. Prof. Lubomir Kenderov pointed out that this is the first comprehensive study from a geological, paleontological, biological and ecological point of view. “The phenomenon is a remnant of an ancient forest of swamp cypresses, approximately 20 million years old, preserved at the bottom of the Black Sea under specific geochemical conditions. This is a unique geo- and bio-phenomenon with no analogues in the world”, he said and added that the area represents an ecosystem with increased biodiversity, but also with a high degree of vulnerability as it is exposed to pressure from various human activities, including pollution, unregulated underwater tourism, shipping.

“With the exhibition that we are opening today, we are not just presenting results. We are making an appeal: The Underwater Petrified Forest must be protected! This is the underwater pearl of the Municipality of Sozopol, and of all of Bulgaria,” the scientist said. He also extended special thanks to the University Underwater Club “South Bay”, whose divers have devoted hundreds of hours to underwater work.

After him, the Vice-President of the Bulgarian Academy of Sciences, Prof. Shtelian Shterionov, emphasized that “The secrets of the sea must gradually become known to all those who cannot dive into the water”.

One of the discoverers of the Underwater Petrified Forest, Prof. Nesho Chipev, spoke about his participation in the first scientific expedition in 1981, organized by the Youth Expedition Club of Sofia University. “We really proved that there is a formation down there, and that it is a forest. We made the first sketches of the location of trees”.

Prof. Hristo Pimpirev, also a participant in the first scientific expedition, emphasized that “The Underwater Petrified Forest in the Sozopol region must be protected because it is unique.”

The opening was also attended by Prof. Dr. Pavel Stoev, Director of the National Museum of Natural History, Sofia, Ms. Olga Rahneva, Secretary of the National Committee for Biological Sciences at the National Science Fund, Ministry of Education and Science of Bulgaria, representatives of WWF-Bulgaria, scientists and guests.

This is the first multidisciplinary study of the natural phenomenon “Underwater Petrified Forest” in the Sozopol Bay. The natural landmark represents the remains of a real forest of swamp cypresses, petrified in past geological eras and preserved to this day in an anoxic environment at the bottom of the Black Sea, at a depth of about 18 meters, in the area between the town of Sozopol and the islands of St. Ivan and St. Peter. Research shows that the age of the Underwater Petrified Forest is about 20 million years.

Scientists also found that today the Underwater Petrified Forest is threatened by various human activities such as pollution of sea waters, unregulated diving tourism, anchoring of vessels, industrial fishing — activities that endanger the fragile underwater world and damage the petrified trees that have survived over millions of years to this day.

The exhibition was prepared by scientists from Sofia University “St. Kliment Ohridski” and the National Museum of Natural History, Sofia as a result of the project “Complex ecosystem study of the water area of the natural phenomenon “Underwater Petrified Forest”, Sozopol Bay”, Project No. KP-06-N61/11-15.12.2022, led by Assoc. Prof. Dr. Lubomir Kenderov, Faculty of Biology of Sofia University “St. Kliment Ohridski”. The project is financed by the National Science Fund, Ministry of Education and Science of Bulgaria.