LA PALMA – The lava flowing into the sea from the volcanic eruption does not only have adverse effects. In the ‘poor’ seabed of the Canary Islands, this provides richer biodiversity if the influx continues for a while.
So says marine biologist José Carlos Hernández of the University of La Laguna in Tenerife. On December 19, an eruption of volcano Cumbre Vieja took place on the Canary Island of La Palma. The lava flow reached the sea on the beach of Los Guirres in the municipality of Tazacorte late Tuesday evening via a 100-metre high cliff. According to the biologist, the sandy soil in this area has a naturally poor biodiversity.
The volcanic eruption is first and foremost a major social drama. More than 6,000 people had to be evacuated from the area. The lava flow has destroyed about 744 houses and buildings. The banana cultivation, which is so important for this region, is also seriously threatened by the volcanic eruption.
In addition to these devastating consequences, the volcanic eruption also has a positive effect from a scientific point of view. Once the boiling mass flowing into the sea cools, the lava will generate a rocky reef that biologists say could provide a new habitat for marine organisms. So-called intertidal areas can then be created with shallow waters, where a lot of food is available for organisms. A little deeper in the sea, the poor sandy soil will be supplemented with a new, richer layer.
In short, biodiversity will increase, but for this, the lava must first have cooled and organisms must start colonising in the area. According to Hernández, small microorganisms such as bacteria will first appear and settle in the lava. This is followed by the algae, which play an important role in the Canary Islands because they are the primary producers in the ecosystem. They create a kind of lawn that grows into an algae forest that in turn is a habitat for other invertebrates and fish.