phycology

Phycology, also known as algology, is the branch of biology that studies algae, a diverse group of photosynthetic organisms ranging from unicellular microalgae to large multicellular seaweeds. Algae inhabit oceans, freshwater, soils, and engineered systems, and they play foundational roles in ecosystems as primary producers and oxygen sources. The field encompasses taxonomy, morphology, physiology, ecology, genetics, and biotechnology of algae. Major taxonomic groups studied include the green algae (Chlorophyta and related groups), the red algae (Rhodophyta), and the brown algae (Phaeophyceae), as well as microscopic lineages such as diatoms, dinoflagellates, and chrysophytes.

Life cycles in algae are highly varied, with some species exhibiting complex alternation of generations and diverse reproductive strategies. Algal ecology covers community interactions, nutrient cycling, and the dynamics of algal blooms, including harmful algal blooms linked to toxins and oxygen depletion.

Applications of phycology include algaculture for food and feed, production of bioproducts such as agar, carrageenan, and alginates, and sources of essential fatty acids and pigments. Algae are explored for biofuels, wastewater treatment, bioremediation, and carbon sequestration, as well as for pharmaceuticals and nutraceuticals.

Research methods combine classical microscopy with molecular phylogenetics, genomics, transcriptomics, and metabolomics, alongside field surveys and culture-based experiments. The field has advanced with DNA-based techniques, leading to revised evolutionary relationships among major algal lineages and a deeper understanding of ancient primary producers and modern biodiversity.