How can algae prevent coastal erosion?

How can algae prevent coastal erosion? MARE researcher João Nuno Franco answers this question in the episode "Soluções naturais para a erosão costeira" of RTP's programme Biosfera.

In the episode broadcast on March 16, the researcher explained how the acceleration of coastal erosion may be related to the decline in algae populations. "In a very simple way, it's a question of pure physics. If we have a force that encounters an obstacle, obviously that force will dissipate, and in that sense kelp algae can play a role," explains João Nuno Franco, regarding the attenuation of wave forces, which aggravate coastal erosion.

In Portugal, as in the rest of the world, there has been a decline in macroalgae populations. In order to optimize the reforestation of these coastal ecosystems, the Polytechnic Institute of Leiria, in collaboration with SeaForester, has dedicated itself to the production of laminaria algae for reintroduction into Portugal's coastal areas. "We get the seeds from natural populations and then we do the whole sowing process here. It will then be sown on these small rocks, and here we manage to maintain the ideal conditions, temperature, light and nutrients, so that it grows healthily, and at the right time, we return it to nature," explains João Nuno Franco.

The MARE researcher ended his participation in the program by saying that this mitigation of coastal erosion varies according to the type of algae that are present: "There are forests that are persistent. They are kelp species that can live up to six, seven, eight, nine, ten-twelve years here on our coast. On the other hand, we have annual species that start growing around January, and by the end of the summer they finish their life cycle. Therefore, forests that are dominated by persistent species will have a greater capacity to mitigate coastal erosion."

"Any vegetation from this algae, no matter how little, will mitigate coastal erosion," concludes the researcher.

To watch the episode click HERE