Below the mid-tide level, some species can tolerate low daily exposure out of the water.
First of all, it is the domain of the toothed kelp ( fucus serratus), a dense, very abundant seaweed, whose sawtooth edges are immediately noticeable in its strips. He never wears vesicles.
When it is in a quiet and sheltered area, it can reach a length of one metre. It is sought for the production of alginates and also for the manufacture of anticoagulants.
In the same area, there are three very characteristic red seaweeds.
The pioka ( chondrus crispus), or small kelp, is dark red. It occurs in very dense tufts about 10 to 20 cm thick and spreads to the bottom of the foreshore. Carrageenans used in the food industry as thickeners are extracted from it to make desserts, for example. It is called E407 on packagings.
Now here is another red seaweed :
It is the dulse ( palmaria palmata), lighter in colour between purple and pink, which also colonizes these rocks. Its tufts have slats with indented ends. Highly sought after for its high protein content, it is used in the food industry as well as in abalone breeding.
Another seaweed is found in this area. The nori ( porphyra) is reddish-brown in colour as seen in the photo below where it neighbors with an ulve.
This seaweed, very rich in vitamins and omega-3s, also contains an anti-cholesterol and is discreetly scented. It is grown in Japan, where more than one million tonnes are produced each year. Marketed in Brittany, it is mainly used to wrap sushis and makis.
Characteristic of the lower limit of the foreshore, the sea spaghetti ( himanthalia elongata) or sea bean, has long flattened strips, which can reach up to three metres.
All these straps start from a spike topped with a small cup that only remains when the young shoots are cut in spring. This abundant seaweed can be used in cooking, for example to accompany meat.
