LIFE ON THE EDGE
Cliffs and shore platforms are challenging environments. It is a space where different species converge and clash, putting their evolutionary capacity to the test. The variable conditions caused by tides, storms, waves, saltpetre, rain and wind create a very changeable environment where only the most adaptable species will survive.
With all these challenges, once again, life shows us its resolve and its beauty. The flysch is also an environment that is brimming with life.
Algae are either brownish-green or red in colour, depending on their exposure to sunlight.
The plant life on the cliffs is very sparse and adapted to the habitat until you reach the top, where wind-blown heath and scrub grow.
Cnidarians use their venomous tentacles to capture shrimps or small fish seeking shelter. The sea tomato fully retracts its tentacles at low tide to store moisture.
The extremely small crustaceans, like the tiny porcelain crab, come in a variety of very peculiar shapes. The velvet crab is the largest of the crustaceans, moulting 11 times in its first year of growth.
Nudibranchs are molluscs that have shed their shells to increase their mobility, but this leaves them exposed and unprotected. Their technique involves sporting different colours. Some go completely unnoticed and others are brightly coloured to draw attention and warn that they may be toxic, even though they are not.
The octopus is the king of the shore platform. Its soft body allows it to take refuge in small crevices by attaching itself to the rocks with its suckers, which it also uses to catch its prey. If it feels threatened, its skin flashes with vibrant colours and it shoots black ink to darken the water and confuse its predator.
Echinoderms are beautiful in shape and colouring. The sea urchin is most common with its protective spines, but we can also find starfish and serpent stars.
The holothurian, better known as the sea cucumber, is like something out of a movie: it is able to shed its own guts to distract predators and then regenerates them completely within two weeks to continue its life.
The fish that live in the shore platform are very small and yet they are very well adapted to shore life. The Lepadogaster’s fins have been adapted into sucking discs to combat the force of the waves.
The Bay of Biscay is like a public square where seabirds from the North Atlantic and the Mediterranean congregate. The main reason why they migrate is always to search for food. If we look carefully with a good pair of binoculars we will discover a wonderful spectacle on the waters off our coastline.
The peregrine falcon is an unstoppable missile. It uses its claws to slash at its prey in mid-air with swoops that can reach 300 km/h. The kestrel hovers in the air watching the ground and attacks insects, reptiles and small mammals.
Cetaceans regularly come to our coastline in pursuit of schools of mackerel or other migratory species. Sometimes individuals get lost and become stranded on the shore.
Cliffs
Vertical life
Life on the cliffs is tough and precarious. The flysch is tumbling away, there is hardly any ground available and saltpetre permeates everything. At the bottom, the swell creates especially tough conditions, but even there, life finds a way.
Beyond the reach of the waves, plants grow in small crevices and ledges and develop thicker leaves to help make the most of the scarce water that is available. If you see a flying bullet, it will be one of the peregrine falcons that nest on the sheerest cliff walls. Yet again, this is evolution at its best.
The foreshore
Life in flux
The tide rises and falls every 6 hours, covering and uncovering the shore platform twice a day. Marine life becomes trapped in small pools where the humidity, temperature, salinity, oxygenation and exposure to sunlight are constantly changing.
Each pools tests their survival skills. Some species change shape or hide, others use this trap to catch their prey, and some are even able to survive outside the water. The octopus is the king of the shore platform, evolution pushed to the limits.