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.
Fucus is a genus of brown algae found in the intertidal zones of rocky seashores almost throughout 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.
Macrocystis is a monospecific genus of kelp with all species now synonymous with Macrocystis pyrifera. It is commonly known as giant kelp or bladder kelp. This genus contains the largest of all the Phaeophyceae or brown algae. Macrocystis has pneumatocysts at the base of its blades. Sporophytes are perennial and the individual may live for up to three years; stipes/fronds within a whole individual undergo senescence, where each frond may persist for approximately 100 days. The genus is found widely in subtropical, temperate, and sub-Antarctic oceans of the Southern Hemisphere and in the northeast Pacific from Baja California to Sitka, Alaska. Macrocystis is often a major component of temperate kelp forests.
Intertidal ecology is the study of intertidal ecosystems, where organisms live between the low and high tide lines. At low tide, the intertidal is exposed whereas at high tide, the intertidal is underwater. Intertidal ecologists therefore study the interactions between intertidal organisms and their environment, as well as between different species of intertidal organisms within a particular intertidal community. The most important environmental and species interactions may vary based on the type of intertidal community being studied, the broadest of classifications being based on substrates—rocky shore and soft bottom communities.
A rocky shore is an intertidal area of seacoasts where solid rock predominates. Rocky shores are biologically rich environments, and are a useful "natural laboratory" for studying intertidal ecology and other biological processes. Due to their high accessibility, they have been well studied for a long time and their species are well known.
Codium is a genus of edible green macroalgae under the order Bryopsidales. The genus name is derived from a Greek word that pertains to the soft texture of its thallus. One of the foremost experts on Codium taxonomy was Paul Claude Silva at the University of California, Berkeley. P.C. Silva was able to describe 36 species for the genus and in honor of his work on Codium, the species C. silvae was named after the late professor.
Mastocarpus stellatus, commonly known as carrageenan moss or false Irish moss, is a species in the Rhodophyceae division, a red algae seaweed division, and the Phyllophoracea family. M. stellatus is closely related to Irish Moss. It grows in the intertidal zone. It is most collected in North Atlantic regions such as Ireland and Scotland, together with Irish moss, dried, and sold for cooking and as the basis for a drink reputed to ward off colds and flu. Marine biologists have completed studies on the medicinal reputation of M. stellatus to discover the full potential of its pharmaceutical benefits. Additionally, marine biologists have conducted research on its potential to serve as an alternative to plastic. The application of M. stellatus in these different industries is correlated with the seaweed's adaptations which developed in response to the environmental stressors present around its location on the rocky intertidal.
Postelsia palmaeformis, also known as the sea palm or palm seaweed, is a species of kelp and classified within brown algae. It is the only known species in the genus Postelsia. The sea palm is found along the western coast of North America, on rocky shores with constant waves. It is one of the few algae that can survive and remain erect out of the water; in fact, it spends most of its life cycle exposed to the air. It is an annual, and edible, though harvesting of the alga is discouraged due to the species' sensitivity to overharvesting.
Durvillaea is a genus of large brown algae in the monotypic family Durvillaeaceae. All members of the genus are found in the southern hemisphere, including Australia, New Zealand, South America, and various subantarctic islands. Durvillaea, commonly known as southern bull kelps, occur on rocky, wave-exposed shorelines and provide a habitat for numerous intertidal organisms. Many species exhibit a honeycomb-like structure in their fronds that provides buoyancy, which allows individuals detached from substrates to raft alive at sea, permitting dispersal for hundreds of days over thousands of kilometres. Durvillaea species have been used for clothing, tools and as a food source by many indigenous cultures throughout the South Pacific, and they continue to play a prominent role in Chilean cuisine.
Durvillaea antarctica, also known as cochayuyo and rimurapa, is a large, robust species of southern bull kelp found on the coasts of Chile, southern New Zealand, and Macquarie Island. D. antarctica, an alga, does not have air bladders, but floats due to a unique honeycomb structure within the alga's blades, which also helps the kelp avoid being damaged by the strong waves.
Durvillaea willana is a large species of southern bull kelp endemic to New Zealand.
Apophlaea is a genus of thalloid algae that is endemic to New Zealand. This genus has two species, both from the high intertidal zone on New Zealand's coasts. Specimens can reach around 15 cm in size. The thalli take a crustose form, but also contain upright, branching frond-like protrusions that reach 5–8 cm in height. Secondary pit connections and secondary pit connectionsare present in the organisms. Apophlaea reproduces by means of conceptacles; it produces tetraspores.
Fucus gardneri is a species of seaweed, a brown alga living on the littoral shore of the Pacific coasts of North America. It has the common names of rockweed and bladderwrack.
Whangapoua Harbour is a shallow natural harbour in the northeast of the Coromandel Peninsula. It is located between Whangapoua in the north, Te Rerenga in the southwest, and Matarangi on the Omara Spit in the north separating it from the ocean. Two boat ramps and a jetty provide boat access into the harbour.
Spongites yendoi is a species of crustose red seaweed with a hard, calcareous skeleton in the family Corallinaceae. It is found on the lower shore as part of a diverse community in the southeastern Atlantic Ocean and the Indo-Pacific Ocean.
Notheia anomala is a macroalga in the family Notheiceae and the brown algae order Fucales. It is an obligate epiphyte of another brown algae, Hormosira banksii.
Hildenbrandia rubra is a marine species of thalloid red alga. It forms thin reddish crusts on rocks and pebbles in the intertidal zone and the shallow subtidal zone. It is a common species with a cosmopolitan distribution, and is able to tolerate a wide range of conditions.
Pseudorhizoclonium is a genus of algae in the Cladophoraceae family.
Lessonia corrugata is a species of kelp, a brown algae in the genus Lessonia, commonly known as strapweed, common crapweed, or Tasmanian kombu. It is a subtidal species endemic to Tasmania and southern Victoria, Australia, and is the least studied of the only three Laminarian kelps in the region. The species was first described by Arthur Henry Shakespeare Lucas in 1931, and is most closely related to the New Zealand species Lessonia variegata.
High densities of Hormosira on a broad rocky platform in Kaikoura, New Zealand
High densities of Hormosira at Long Reef, Sydney, Australia
Hormosira at Eaglehawk Neck, Tasmania, Australia
Hormosira growing alongside a petrified log at Curio Bay, Otago, New Zealand
