Knotted wrack | DE L'EAU À LA BOUCHE

Frondes formant de longues lanières ramifiées et étroites, sans nervure centrale.

De couleur variant du vert olive au jaunâtre et au brun.

Les axes principaux de la fronde portent ici et là des vésicules remplies d’air, qui permettent à l’algue de flotter.

Les réceptacles se trouvant le long des frondes, sous la forme de petites boules attachées par une tige fine, ils produisent œufs ou sperme selon le genre de l’algue.

Nom

Goémon noir
Ascophyllum nodosum

Type

Brown algae

Autres appellations

Nom en cuisine

État de la ressource

Not a cause for concern

Saison de consommation

Fresh from April to December.

Processed all year round. Generally as a dried product.

SIZE : Up to 3 m long.

ESPÉRANCE DE VIE : Up to 20 years.

CYCLE DE VIE : Sexual maturity from age 5.

Plants are either male or female. Reproduction takes place in spring. After this, and once the embryos have been released into the water, the receptacles detach from the mother plant. After fertilization, the embryo settles to the bottom. As it is sensitive to waves, a calm spot is best for it to settle.

The young shoots will attach themselves nearby and gradually colonize the environment. They leave so little space between each other that other species of algae would find it difficult to establish themselves.

The knotted wrack seaweed can also regenerate from its holdfast.

One, two, three…

You want to know the age of the knotted wrack? It’s easy. Just count the number of vesicles on the main stem. In fact, each one corresponds to a year of life, except for the first year.

Coastal zone, between high and low tide limits, up to 15 m deep and above where rockweed is found.

Knotted wrack prefers relatively calm, sheltered environments, such as bays, where it forms dense bushes.

Photographie sous-marine d'une forêt d'algues vertes, longues avec des bulbes.

Knotted wrack leave so little space between each other that other species of algae would find it difficult to establish themselves.
Credit : Éric Tamigneaux

Voir l’image en plein écran

PREYS :

CO2
Solar energy

PREDATORS :

Herbivorous mol-luscs
Grazing fish

MACHINES : Hand harvesting.

REGULATIONS :
Cut the algae at least 15 cm from the spike. A higher cut enables faster regrowth.

Take care to preserve the holdfasts, as they allow the knotted wrack to regenerate.

Harvesting takes place at low tide.

Alternate between areas that are cut and areas that are left untouched. Moreover, only every second frond is harvested, to preserve the resource.

Wait 3 years before re-harvesting Knotted wrack on the same site. This gives the algae time to regenerate.

The harvesting period varies depending on the location: from April to December in the Gaspé Bay and from June to November in the Lower St. Lawrence.

BENEFITS :
Knotted wrack is a good source of iodine, iron, calcium, magnesium, vitamin B12, and fiber.

LET’S COOK :
Knotted wrack has an umami flavor, which is strongly marine and iodized. It is similar to that of oysters. It can act as a flavor enhancer.

When fresh, its texture is tough and fibrous.

The waters of the St. Lawrence are known for their good quality. However, as algae absorb the elements present in the water in order to grow, it is preferable to make sure that the harvesting site is clean before eating them fresh.

Ascophyllum to the rescue

Recent research shows that spraying tomatoes with ascophyllum extract improves their growth and helps them resist various stresses, including lack of water.