IHCantabria researchers measure the capacity of mangroves throughout their life to attenuate waves and protect coasts

Researchers from the Environmental Hydraulics Institute of the Universidad de Cantabria (IHCantabria) have published the results of a study that predicts and confirms the capacity of mangrove forests to attenuate marine waves and protect coasts. Under the title “Predicting the evolution of coastal protection service with mangrove forest age”, María Maza, Javier López Lara and Íñigo Losada sign an article recently published in the prestigious scientific journal “Coastal Engineering”, concluding for example that, five years after being planted or restored, mangroves already offer their maximum protection capacity in medium wave conditions, and maintain it throughout their life.

These data are “fundamental” for policies to restore and protect these coastal ecosystems, explains María Maza, who belongs to the Climate, Energy and Marine Infrastructures group at the University of Cantabria and the Hydrodynamics and Coastal Infrastructures group at IHCantabria. In developing countries there is no strict legislation to protect mangroves, which “have historically been very badly treated, for example to create pools for shrimp farming”. According to the researcher, this type of installation entails the deforestation of the environment, they are highly polluting and, after a few years and when they are no longer productive, they are abandoned and the ecosystem is degraded”.
The work carried out by the researchers allows the mangrove forests to be put to good use as a coastal protection solution. “It all began with some tests we carried out at the IHCantabria facilities, with 134 mangrove replicas, to quantify the wave attenuation they produced,” says Maza. In 2019 they obtained some initial results, concluding that, in a geometry as complex as that of the mangrove, they could use a single variable to determine its energy attenuation capacity: the solid submerged volume.

“Based on this, what we have done in this new work is to obtain the attenuation capacity throughout the life of the mangrove, so that we can know the protection offered by very young mangroves or that offered by adults,” says the scientist. The data on temporal evolution are “very relevant” for restoration campaigns because they answer a key question: how long do I have to wait for the forest to provide the coastal protection service I need?

The fact that this maximum protection capacity will occur after just five years could benefit “thousands of people around the world”, since mangroves are ecosystems present on the coasts of many countries, where they “provide a daily coastal protection service that should be valued”, says María Maza. “We hope that these results will help coastal managers in restoration work, and also to raise public awareness of the importance of conserving these ecosystems.

To know more:

“Predicting the evolution of coastal protection service with mangrove forest age”, María Maza, Javier L. Lara, Íñigo J. Losada: https://doi.org/10.1016/j.coastaleng.2021.103922