For thousands of years, the Caribbean mangroves of Colombia recorded the advances and retreats of the sea. At the same time, they acted as a natural defense against storms and extreme climate changes.
Thus, these ecosystems functioned as a living archive of the coastline. However, this natural memory is seriously threatened.
In recent decades, the disappearance of mangroves has accelerated alarmingly. Colombia lost more than 80% of the Caribbean mangroves, which once covered about 4,500 km². Currently, only a few hundred square kilometers survive. The rate of loss is around 8.5 km² per year.
This degradation not only impacts the coastal biodiversity. It also weakens the natural protection of populations and human settlements. Therefore, the retreat of the mangrove exposes the coastline to increasing risks. The coastal stability is increasingly compromised.
The coastline as a living system
Research conducted in places like the Ciénaga Grande de Santa Marta, the Caimanera in Coveñas, and the Tayrona National Natural Park allows for the reconstruction of the environmental history of the Caribbean. To do this, sediment layers extracted through drilling are analyzed. Each centimeter represents decades of environmental changes.
In these columns, sands, silts, and organic remains appear, revealing landscape transformations. Through pollen and plant fragments, it is identified which ecosystems dominated at each stage. In this way, vegetation acts as a key indicator. Salinity defines the ecological boundaries between sea and continent.
When the sea level advances or retreats, the coastal vegetation shifts. This movement is recorded underground as a trace of time. Thus, mangroves narrate the history of marine transgressions and regressions. Reading this story allows for anticipating future scenarios.
The role of mangroves in the ecosystem
The mangroves fulfill essential functions for environmental balance. They retain sediments, reduce wave energy, and stabilize the coastline. Additionally, they promote the accumulation of organic matter. This allows the soil to gradually rise.
When the mangrove remains active, the terrain can grow several millimeters per year. This natural process protects against erosion and the advance of the sea. Therefore, they are considered a living barrier. Their loss leaves the coast without defense.
In turn, these ecosystems support a high biodiversity. They function as a refuge and breeding area for fish, crustaceans, and birds. They also regulate the water quality. Their degradation impacts the entire coastal ecological network.
Urgent decisions in the face of climate change
Scientific records show that the disappearance of the mangrove increases vulnerability to rising sea levels. Additionally, extreme events such as storms and possible tsunamis generate growing concern. In this scenario, inaction is no longer an option. The accumulated evidence is compelling.
The recovery of historical mangrove areas emerges as an effective alternative. Unlike concrete walls, these nature-based solutions restore ecosystems and generate local employment. Moreover, they strengthen climate resilience. The technology to do so already exists.
While the Caribbean has detailed studies, the Pacific coastline presents large information gaps. This lack of data increases uncertainty about its vulnerability. Therefore, reconstructing the environmental history is not an academic exercise. It is a key tool to protect the future of the Colombian coastline.
