Seaweed diving in Marseille National Park of the Creeks

Algae

Vx-ALG-Codium bursa-Tiboulen-20m-22-04-04-VMSG1 VxAlgVerte-Acetabularia acetabulum ex Mediterranea-Carapègue VxHugo-Vx-Algae-Pharillons-5m-03-04-04-vmsg VxHugo-Vx-algae-glider-5m-04-04-04-VMSG1 VxHugo-VXALG--Pharillons-10m-03-04-04-vmsg

Number : On more than 375 000 plants listed on Earth, about 1600 macro algae are observed in European waters and only 66 are in the Weinberg (the ' Bibles ' Mediterranean and Atlantic of the diver F&F ' generalist '). The algae pose no danger to divers and their presence is the pleasant setting of the discovery of the underwater environment. It should be noted that if algae are very nutritious, they are neglected in the West but are very much appreciated in the Far East.

Definition : Vegetable organism, usually aquatic, practicing photosynthesis. (Larousse-2005).

Autotrophy: Absorbs carbon dioxide and releases oxygen by manufacturing the first organic compounds of food chains: carbohydrates.

Identification criteria : Plant without stem (stipe) or leaf (sling) or root (spikes or adhesive discs): No vascularization, the exchanges are made directly at the level of the thallus cells. Presence of cellulose in cell membranes.

Diversity :

Dimensions: From a few centimetres to several tens of meters (the Kelp of California).

Forms: Encrusting (Crambe Crambe), erect (Cystoseires, laminar – sometimes maintained by floats, Sargasso, Fucus), in Ball (Basque beret), more or less calcified (sidewalk, Maerl, Corallie, Poseidon currency).

Colors: Green – Brown – red, the color makes it easy to distinguish the different Classes of algae. Each color of seaweed has are own reproductive mode which allows to grant scientists and street divers!

Distribution: Limited in depth due to the rapid loss of brightness. Maximum: 50 to 100 meters in clear water. Predominance of red algae around 40 meters. Particular case of the characteristic floors of the foreshore with the more or less important discovery of the coastline

Depending on the tides (exceptional case of the Pelvétie).

Channels Food : First mandatory links. Dedicated predators exist: some snails (Helcion), some slugs (sea hare), etc. Aside from Saupes, few species of fish graze only on algae.

Reproduction: Algae have a reproductive mode that is not observable without material. However, the spiral Fucus has well-visible terminal receptacles (types of blisters filled with gametes).

In algae, both modes of reproduction exist: cuttings (facilitates dispersal of laTaxifollia) and sexual reproduction by Gametes released in full water (the herb to Robert).

The sexual reproduction of algae is very complicated, especially for red algae!

Receive your News dive training and your free guide !

Free dive guide

We do not spam! See our privacy policy for more information.