Uncovering the Role of Black Sea Shipwrecks  in Carbon Removal

Post #2 - april 14, 2023

Have you ever wondered how ancient shipwrecks can still be preserved after centuries of being submerged in the ocean? The answer lies in the unique conditions of the Black Sea, which beyond its beauty, holds an incredibly rich history that is frozen in time. 

Photo: Rodrigo Pacheco-Ruiz

The Black Sea is the largest basin worldwide that is anoxic below 200m, meaning there is no oxygen from this depth to its bottom, which reaches a depth of a couple of kms. This lack of oxygen prevents many microbes from breaking down organic matter, including wooden shipwrecks. As a result, the shipwrecks in the Black Sea have remained intact for hundreds, and even thousands of years.

The Black Sea is known not only for its preserved shipwrecks but also for its role in carbon removal. In fact, the Black Sea is one of the largest carbon sinks in the world, with millions of tons of carbon stored on its sea floor. Each year, the Black Sea sequesters a million tons of CO2 from the atmosphere by absorbing leaves, branches, trees and other organic matter carried by rivers. This carbon has been preserved for thousands of years, making a significant contribution to regulating the Earth's climate.

By relocating organic material to the Black Sea floor, Rewind plans to accelerate this natural process and make a significant contribution to mitigating climate change. As part of our research, we are measuring how long carbon has been preserved in shipwrecks and in the sediment of the deep sea. We're using a combination of laboratory experiments, in situ measurements, carbon content assessment, and lignin-cellulose analysis to validate our decomposition model. We believe high-quality carbon removal solutions should be meticulously proved by science and accurately measured with technology.

Sediment sampling in the Black Sea as part of Rewind’s Experiments
Carbon analysis of ancient wooden shipwreck in the Rewind Lab

The Black Sea shipwrecks originally sent us, the Rewinders, down the path of sequestering organic carbon in the Black Sea. As we make progress with our research, we realize two important things: though extremely slowly, organic carbon does break down even in anoxic conditions. But in addition, the sediment retains a lot of the carbon and the stagnant water of the deep Black Sea keep it from mixing up the water column. We continue to be fascinated and inspired by nature, and are committed to develop the most scalable, efficient, and ecological carbon removal solution in the world.