Brown algae are a large group of multicellular algae comprising the class Phaeophyceae. They include many seaweeds located in colder waters of the Northern Hemisphere. Brown algae are the major seaweeds of the temperate and polar regions. Many brown algae, such as members of the order Fucales, commonly grow along rocky seashores. Most brown algae live in marine environments, where they play an important role both as food and as a potential habitat. For instance, Macrocystis, a kelp of the order Laminariales, may reach 60 m (200 ft) in length and forms prominent underwater kelp forests that contain a high level of biodiversity. Another example is Sargassum, which creates unique floating mats of seaweed in the tropical waters of the Sargasso Sea that serve as the habitats for many species. Some members of the class, such as kelps, are used by humans as food.
In phycology, a pneumatocyst is a floating structure that contains gas found on brown seaweed. A seaweed's thallus may have more than one. They provide buoyancy to lift the blades toward the surface, allowing them to receive more sunlight for photosynthesis.
Caulerpa is a genus of seaweeds in the family Caulerpaceae. They are unusual because they consist of only one cell with many nuclei, making them among the biggest single cells in the world.
Ascophyllum nodosum is a large, common cold water seaweed or brown alga (Phaeophyceae) in the family Fucaceae. Its common names include knotted wrack, egg wrack, feamainn bhuí, rockweed, knotted kelp and Norwegian kelp. It grows only in the northern Atlantic Ocean, along the north-western coast of Europe including east Greenland and the north-eastern coast of North America. Its range further south of these latitudes is limited by warmer ocean waters. It dominates the intertidal zone. Ascophyllum nodosum has been used numerous times in scientific research and has even been found to benefit humans through consumption.
Halimeda is a genus of green macroalgae. The algal body (thallus) is composed of calcified green segments. Calcium carbonate is deposited in its tissues, making it inedible to most herbivores. However one species, Halimeda tuna, was described as pleasant to eat with oil, vinegar, and salt.
A raceway pond is a shallow artificial pond used in the cultivation of algae.
Dictyotales is a large order in the brown algae containing the single family Dictyotaceae. Members of this order generally prefer warmer waters than other brown algae, and are prevalent in tropical and subtropical waters thanks to their many chemical defenses to ward off grazers. They display an isomorphic haplodiploid life cycle and are characterized by vegetative growth through a single apical cell. One genus in this order, Padina, is the only calcareous member of the brown algae.
Pylaiella (mung) is a genus of seaweed that can be a nuisance due to its ability to coat people, ropes, animals, and more when it blooms close to the shore under particular conditions.
Turbinaria is a genus of brown algae (Phaeophyceae) found primarily in tropical marine waters. It generally grows on rocky substrates. In tropical Turbinaria species that are often preferentially consumed by herbivorous fishes and echinoids, there is a relatively low level of phenolics and tannins.
Hypnea is a genus of red algae, and a well known carrageenophyte.
Chlorella sorokiniana is a species of freshwater green microalga in the Division Chlorophyta. It has a characteristic emerald-green color and pleasant grass odor. Its cells divide rapidly to produce four new cells every 17 to 24 hours. The alga was described by Martinus W. Beijerinck in 1890. In 1951, the Rockefeller Foundation in collaboration with the Japanese Government and Hiroshi Tamiya developed the technology to grow, harvest and process Chlorella sorokiniana on a large, economically feasible scale. This microalga has also been used extensively as a model system to study enzymes involved in higher plant metabolism.
Pyropia is a genus of red algae in the family Bangiaceae. It is found around the world in intertidal zones and shallow water. The genus has folding frond-like blades which are either red, brown or green. Some Pyropia species are used to create nori, and are thus important subjects for aquaculture.
Caulerpa cupressoides, commonly known as cactus tree alga, is a species of seaweed in the Caulerpaceae family. Green alge of Caulerpa genus are salty and pungent in style and are consumed by several marine cultures around the world.
Dictyota is a genus of brown seaweed in the family Dictyotaceae. Species are predominantly found in tropical and subtropical seas, and are known to contain numerous chemicals (diterpenes) which have potential medicinal value. As at the end of 2017, some 237 different diterpenes had been identified from across the genus.
Susan Brawley is an American marine ecologist at the University of Maine known for her research on algae, especially algal reproduction. She was elected a fellow of the American Association for the Advancement of Science in 2012.
Joanna M. Jones was a phycologist, marine biologist and diver. She researched kelp forest ecology adding to the scientific knowledge on its population, reproduction, competition and growth as well as descriptions of subcanopy seaweeds found in kelp forests. She was president of the British Phycological Society from 1987 to 1988.
Mesospora negrosensis is a species of macroalga occurring in the western Atlantic.
Padina is a genus of brown macroalgae in the family Dictyotaceae.
Champia novae-zelandiae is a species of seaweed.
