''Phyllospora comosa'', known as crayweed, is a species of

brown algae Brown algae (: alga) are a large group of multicellular algae comprising the class (biology), class Phaeophyceae. They include many seaweeds located in colder waters of the Northern Hemisphere. Brown algae are the major seaweeds of the temperate ...

in the

Seirococcaceae The Seirococcaceae are a family of brown alga Brown algae (: alga) 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 ...

family. It forms temperate seaweed forests that are important as habitat for many marine species and also for producing oxygen and capturing atmospheric carbon.

Taxonomy

''Phyllospora comosa'' is commonly known as crayweed. It is a species of brown algae in the Seirococcaceae family.

Description

Crayweed grows up to in length and forms dense, shallow forests.

Distribution

Crayweed is found in the oceans around Australia and New Zealand. It is abundant in cooler waters along the south-eastern coastline of Australia, around

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

and in

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

. It occurs to a depth of around on the east coast and farther south to about . On some Tasmanian coasts it can occur depths of at . It used to occur around

Sydney Sydney is the capital city of the States and territories of Australia, state of New South Wales and the List of cities in Australia by population, most populous city in Australia. Located on Australia's east coast, the metropolis surrounds Syd ...

, but disappeared from metropolitan areas under pressure from human activities during the 1970s and 1980s. The

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

have a central main axis, usually up to long, which bear many branches along their length, with closely arranged, leaf-like laterals. Some laterals have

conceptacles Conceptacles are specialized cavities of marine and freshwater algae that contain the reproductive organs. They are situated in the receptacle and open by a small ostiole.Boney, A.D. (1969). ''A Biology of Marine Algae''. Hutchinson Educational ...

, in which develop cells which produce sperm and eggs. The strongly seasonal growth of the algae depends on the length of daylight; it occurs from

apical cells Apical means "pertaining to an apex". It may refer to: *Apical ancestor, refers to the last common ancestor of an entire group, such as a species (biology) or a clan (anthropology) *Apical (anatomy), an anatomical term of location for features loc ...

and is restricted to the top of the branches.

Ecological significance

Crayweed forests are important as habitat for many marine species and also for producing oxygen and capturing atmospheric carbon.

Conservation efforts in Sydney

A conservation effort known as "Operation Crayweed" has been working to re-establish the species in the waters around Sydney. Transplants have been established at sites including Malabar, Coogee,

Little Bay Little Bay is a suburb in the Eastern Suburbs of Sydney, in the state of New South Wales, Australia. Little Bay is located 14 kilometres south-east of the Sydney central business district and is part of the local government area of the City of ...

Freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

, and Bondi; other transplants were being planned for Newport and

Dee Why Dee Why is a coastal suburb of northern Sydney, in the state of New South Wales, Australia, 18 kilometres north-east of the Sydney central business district. It is the administrative centre of the local government area of Northern Beaches ...

. In 2022 Operation Crayweed was absorbed into a larger

biodiversity Biodiversity is the variability of life, life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and Phylogenetics, phylogenetic diversity. Diversity is not distribut ...

restoration project, led by the

Sydney Institute of Marine Science The Sydney Institute of Marine Science (SIMS) is a research institute focused on marine science in Sydney, Australia. It is a partnership among four Sydney universities: Macquarie University, the University of NSW (UNSW), the University of Sydne ...

, called

Project Restore The Sydney Institute of Marine Science (SIMS) is a research institute focused on marine science in Sydney, Australia. It is a partnership among four Sydney universities: Macquarie University, the University of NSW (UNSW), the University of Sydne ...

, with funding from the NSW Government.

Taxonomy

Description

Distribution

Ecological significance

Conservation efforts in Sydney

References

Further reading