makroalg

Makroalg, also known as macroalgae or Makroalgen in some languages, denotes large, photosynthetic algae that inhabit marine environments. Unlike microalgae, makroalg are multicellular and lack true vascular tissue; they belong to several distinct groups, most notably the brown algae (Phaeophyceae), red algae (Rhodophyta), and green algae (Chlorophyta).

Anatomy and biology: Makroalg range from a few centimeters to tens of meters in length. Their thalli may bear holdfasts, stipes, and blades; many are kelp-like with gas-filled bladders. They contain pigments such as chlorophyll a and accessory pigments—fucoxanthin in brown algae, phycoerythrin and phycocyanin in red algae—providing color and photosynthetic efficiency. Their cell walls contain cellulose and seaweed-specific polysaccharides; brown macroalgae produce alginates, while red macroalgae produce agar and carrageenan.

Distribution and habitat: Makroalg are primarily marine, inhabiting coastal zones worldwide from the intertidal to subtidal zones. They form habitats that shelter diverse communities and contribute to nutrient cycling; some groups tolerate brackish water, while others are restricted to particular environmental conditions such as light and temperature.

Uses and economy: Makroalg are harvested for food (such as kelp, nori, wakame) and as sources of thickening agents—alginate, agar, and carrageenan—for food, pharmaceuticals, and cosmetics. They are also explored for animal feed, fertilizer, bioplastics, biofuels, and carbon sequestration. Offshore farming and integrated multi-trophic aquaculture are expanding industry opportunities.

Conservation and cultivation: Sustainable cultivation reduces pressure on wild stocks and supports coastal livelihoods. Practices include responsible species selection, monitoring for invasive species, and minimizing environmental impacts. Ongoing research covers breeding for desirable traits, bioproduct development, and the environmental benefits of macroalgal ecosystems.