The tidal area, that is to say, the area of the coastline that becomes exposed at low tide, is the ideal place to observe marine flora and fauna and the ecological processes taking place on the rocky bottoms. This is a low-key tour, but appropriate footwear is essential if we want to spare ourselves any slips. Above all, it provides an excellent opportunity to breathe in the sea breeze and the smell of salt and iodine, as well as listening to the sound of crashing waves. Observation becomes more in-depth and educational if we manage to bring along an expert in the development of life in these spaces.
It is precisely the varied species of algae that colour the water and release that potent and pleasant smell, but there are many other invertebrate animals inhabiting the area – limpets, sea snails, crabs, worms, sea anemones, sea urchins, etc. -, certain fish species – rocky gobies, ornate wrasses, thicklip grey mullets, etc. – and bird species – herons, slender-billed curlews, plovers, etc. -. With a little bit of luck and enough patience, you will be able to behold spectacles such as octopuses catching crabs, sometimes they even have to stick their tentacles out of the water, or a heron hunting for fish at a puddle. Algae, herbivore and carnivore animals comprise the intertidal food chain, in which birds are the strongest link alongside men. At high tide, the sea brings in plankton for filter feeders, and many herbivore and carnivore fish swim in looking for food. Human extractions focus on herbivore animals, primarily on limpets, sea snails, and sea urchins, and on carnivores such as the octopus.
Looking from afar, the presence of an apparent order in the development of life in the tidal strip cannot be appreciated. We can only make out the dry patches, puddles and pools. But if we take a closer look, we will be able to see that organisms form horizontal stripes that fill the coastline with colour and add up to this landscape that changes as seasons do. The rocks that are left dry on the ebb are home to the organisms that better stand up to the desiccation, that is to say, those that tolerate or even need to be exposed to the open air for a certain period of time (certain algae, limpets, sea snails, and barnacles, for instance). The latter are behind the wide yellowish stripe visible at half-tide. There are other organisms that inhabit the masses of water that form the puddles and pools and are prepared to bear significant swifts in ambient salinity and temperature, but not dissecation. Due to the fact that habitats in the upper stripes – both in the dry rocks and in the puddles – are exposed for longer periods of time at low tide, life conditions are harder and only a handful of species can resist them. As the tide rises, surrounding conditions become milder and the number of species found increases exponentially, all the while competing species replace one another. The process of resistance to life conditions on the upper end combined with the competing process taking place on the lower end give raise to the abovementioned horizontal stripes layout.
There are excellent, extensive tidal areas to be found in Tenerife, showing a large amount of puddles and pools. Spots such as Punta del Hidalgo, Valle Guerra, Los Silos-Buenavista, and El Médano are highly recommended. We invite everyone to make the most of the striking experience that is touring the tides.