by Yekaterina BLINOVA, Cand. Sc. (Biol.), Leading Research Scientist, All-Russia Research Institute of Sea Fishing and Oceanography
Seaweeds (algae) are the oldest photosynthetic organisms of the earth known to have created its oxygen atmosphere. The land plants come from them. The role of this wonderful family of the plant kingdom is immense indeed. First and foremost, the algae are the primary "producers" of organic matter from inorganic one, the cornerstone of our planet's ecological pyramid. Although their biomass in the World Ocean is something like 1.7 bln tons, their annual produce amounts to as much as 550.2 bln.
Marine life, especially in the off-shore zones subject to anthropogenic effects, owes its existence to algae in the long run. They bring down water pollution, they give food and shelter to many invertebrates and fish - to fry in the first place, and they serve as a substrate (attachment base) for sea animals and fish roe.
Algae are quite diverse in color, size, structure and form: they may be filamentous, laminar and ramified (branched). Some have small stems and what looks like leaflets; and those growing on solid ground are supplied with anchoring organs like rhizoids, soles and suckers.
Physiologically, sea plants are precious. Their layers accumulate, selectively, mineral elements at concentrations dozens and even thousands of times as high as the ambient water. Large algae, the macrophytes, absorb light and nutrients by their entire surface.
Our country is washed by thirteen seas, mostly in the temperate zone. The total biomass of seaweeds tops 10 mln tons, and their yearly produce is severalfold as high. Our seas are inhabited by 850 - 900 macrophyte species (around 170 species of green algae, about 250 red and 450 brown algae species) as well as a variety of sea grasses (Monocotyledoneae) .
The offshore macrophytobentos is formed for the most part by brown - laminar and focus (Fucaceae) - algae, which are the largest. They ... Read more