The strip of coastline between the Malpaís de Rasca, Arona, and Guía de Isora, is one of the areas of the Canary Islands that has undergone the most transformations in recent decades, to the point of creating an environment that has nothing to do with the one that there was and it runs serious risks of disappearing. “We are witnessing a massive loss of natural beaches due to human action,” warns doctor of Geography and researcher Néstor Marrero Rodríguez, from the Institute for Oceanography and Global Climate Change (IOCAG) of the University of Las Palmas de Gran Canaria, who also warns that the transformations undertaken by human beings leave the beaches defenseless against the effects of climate change.
Marrero Rodríguez is part of a team that in recent months has analyzed the changes, transformations and behavior of 450 beaches throughout the Canary Islands, an investigation that includes the IOCAG itself and the Department of Geography and History of the University of La Laguna. . And he is clear that the greatest transformations have been carried out in the coastal strip between the Rasca malpaís and the municipality of Guía de Isora, together with the south of Gran Canaria.
In addition to analyzing human action on the beaches, the research team has analyzed the reviews left by visitors on Google Maps and has surveyed 850 people about the tastes of the foreign and resident population. “We continue to transform the coastline to please. We do not “sell” what the Canary Islands are, but we change it to adapt it to the preferences of tourists”, explains this expert, who highlights the first conclusions about tastes, drawn from online reviews while the surveys carried out are ordered and studied. .
The preferences indicate that beach users prefer that they be natural sand, secondly sand transformed (blonde sand, for example, in places where it was originally black), and thirdly, callao .
Which, however, would go against what has happened in recent decades. “Historically, it has been considered that blonde sand is preferred over natural black or pebble sand,” emphasizes Néstor Marrero, who also stresses that “transforming beaches costs a lot of money. A refill of sand, for example, costs 500,000 euros, while construction projects for a new beach can reach 25.4 million euros, in cases such as Santa Cruz de La Palma”, recalls this researcher.
The study has evaluated eight types of changes in the Canary Islands beaches: the color of the sediment, the size of the grain, if there has been feeding on the beach, the construction of infrastructures to modify the waves, the creation of artificial beaches where there were none, the generation of coastal promenades or not, the construction of marinas and the modification of the surfaces of the beaches.
One of the conclusions of the research is that beaches have memory. In El Médano, for example, the dune dynamics still corresponds to the changes suffered by the extraction of aggregates more than forty years ago.
In addition, when the beaches have not suffered human interventions, they are capable of responding or defending themselves against changes such as the rise in sea level, storm surges or the reduction in sediment contributions.
One of these mechanisms is that, in the event of seasonal storms, they lose their sand and fill with pebble until they return to normal and the pebble will give way again to the sand for the arrival of summer.
What can be done to remedy this situation? For this researcher, “we have such a transformed coastline in the south of Tenerife that it is unthinkable to renaturate everything. The most appropriate thing would be to return the natural characteristics to those sections in which it is viable, to preserve the coastline that has not yet been altered and for the universities and the Administration to join hands when it comes to undertaking transformations because the reality is that we are loading the coastline by leaps and bounds. Ideally, management would be based on scientific research”.
“In the coming decades the beaches will suffer significant stress due to climate change and human transformation has left them without natural tools to adapt. With the rise in sea level, many of these beaches, as we know them, will not survive because we have changed the natural response process to different phenomena. An example of this is that the beaches do not have space inland to relocate due to the construction of coastal promenades.
