Polysiphonia invasions

Polysiphonia is known as an invasive algae in many locations throughout the world. Furthermore, many invaders and their impacts have probably gone unnoticed because many native species have invasive sibling species, that is, related species which are difficult to tell apart, but which cannot produce fertile hybrids. Click to learn more about two examples of invasive Polysiphonia species: P. harveyi, which is now found in several locations worldwide, and P. breviarticulata, which occurred in bloom proportions in North Carolina in 1988.

Polysiphonia harveyi is found in Japan, Europe, Nova Scotia, California, New Zealand and North Carolina. It’s appearance in various European locations during the past 170 years, especially its introduction and subsequent rapid spread in the British Isles in the early 1900s, prompted researchers to look at where it originally came from and how it was spreading.

Studying interbreeding data, rcbL sequences and chromosome analysis of P. harveyi from various locations from around the world revealed that there are two invasive lineages. P. harveyi found in the North Atlantic, including Europe and Nova Scotia, are from one source near Hokkaido, Japan. This spread from Japan to Europe may have occurred with the transport of oysters, as with many European macroalgae; alternatively, it may have hitchhiked on shipping vessels or other macroalgae. The other invasive lineage of P. harveyi is found in California, North Carolina and New Zealand, and originated in Honshu, Japan. It is likely that the California populations spread naturally. The New Zealand populations, whose introduction went unnoticed because of sibling species in the area, were probably introduced by shipping. On the North Atlantic coast, both lineages are found; those from colder Hokaido are found farther north in Nova Scotia, and those from the warmer Honshu are found farther south in North Carolina.
Many features of P. harveyi contribute to its role as an invader. It can survive at a wide range of temperatures and it forms bromophenols, which deter grazing by being toxic to microalgae. It grows abundantly on many substrates, including drifting macroalgae and artificial surfaces such as fish cages and mooring facilities. Because it seems to favor artificial substrates in marinas and harbors, it fortunately does not seem to have a great effect on native communities.

P. breviarticulata was collected for the first time in the Western Atlantic in North Carolina in December 1982 and soon became established as a common member of the flora. In late spring and summer 1988, drifting P. breviarticulata occurred in bloom proportions along 200 kilometers of coastline, from Cape Lookout North Carolina to Myrtle Beach, South Carolina, and in some areas, formed piles on beaches 30-40 cm deep and several meters wide. It became a nuisance on beaches and an impedement to trawler and sinknet fishermen, who reported problems with their nets becoming fouled. This is the first record of Polysiphonia occurring as a free-floating bloom.
P. breviarticulata, a Mediterranean species, may have been introduced to North Carolina by currents. It is thought that growth and reproduction are normally curtailed when waters exceed 20-24°C. The bloom during 1988 may have been caused by unseasonably cool surface water temperatures which lengthened the effective growth season by six to eight weeks.

Polysiphonia Morphology | Life History | Taxonomy | Ecology

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MARINE BOTANY Monterey Bay Flora Seagrasses Green algae Red algae Brown algae Phytoplankton Lichens Methods Habitats Bibliography Glossary Syllabus Students PHYCOLOGICAL SOCIETY OF AMERICA	Plysiphnia Eclgy: Invasions Substrates \| Animal Communities \| Invasions \| Ecology Home Polysiphonia is known as an invasive algae in many locations throughout the world. Furthermore, many invaders and their impacts have probably gone unnoticed because many native species have invasive sibling species, that is, related species which are difficult to tell apart, but which cannot produce fertile hybrids. Click to learn more about two examples of invasive Polysiphonia species: P. harveyi, which is now found in several locations worldwide, and P. breviarticulata, which occurred in bloom proportions in North Carolina in 1988. Polysiphonia harveyi is found in Japan, Europe, Nova Scotia, California, New Zealand and North Carolina. It’s appearance in various European locations during the past 170 years, especially its introduction and subsequent rapid spread in the British Isles in the early 1900s, prompted researchers to look at where it originally came from and how it was spreading. Worldwide distribution of P. harveyi Studying interbreeding data, rcbL sequences and chromosome analysis of P. harveyi from various locations from around the world revealed that there are two invasive lineages. P. harveyi found in the North Atlantic, including Europe and Nova Scotia, are from one source near Hokkaido, Japan. This spread from Japan to Europe may have occurred with the transport of oysters, as with many European macroalgae; alternatively, it may have hitchhiked on shipping vessels or other macroalgae. The other invasive lineage of P. harveyi is found in California, North Carolina and New Zealand, and originated in Honshu, Japan. It is likely that the California populations spread naturally. The New Zealand populations, whose introduction went unnoticed because of sibling species in the area, were probably introduced by shipping. On the North Atlantic coast, both lineages are found; those from colder Hokaido are found farther north in Nova Scotia, and those from the warmer Honshu are found farther south in North Carolina. Many features of P. harveyi contribute to its role as an invader. It can survive at a wide range of temperatures and it forms bromophenols, which deter grazing by being toxic to microalgae. It grows abundantly on many substrates, including drifting macroalgae and artificial surfaces such as fish cages and mooring facilities. Because it seems to favor artificial substrates in marinas and harbors, it fortunately does not seem to have a great effect on native communities. top P. breviarticulata was collected for the first time in the Western Atlantic in North Carolina in December 1982 and soon became established as a common member of the flora. In late spring and summer 1988, drifting P. breviarticulata occurred in bloom proportions along 200 kilometers of coastline, from Cape Lookout North Carolina to Myrtle Beach, South Carolina, and in some areas, formed piles on beaches 30-40 cm deep and several meters wide. It became a nuisance on beaches and an impedement to trawler and sinknet fishermen, who reported problems with their nets becoming fouled. This is the first record of Polysiphonia occurring as a free-floating bloom. P. breviarticulata, a Mediterranean species, may have been introduced to North Carolina by currents. It is thought that growth and reproduction are normally curtailed when waters exceed 20-24°C. The bloom during 1988 may have been caused by unseasonably cool surface water temperatures which lengthened the effective growth season by six to eight weeks. top Polysiphonia Morphology \| Life History \| Taxonomy \| Ecology Acknowledgements \| Home © Sarah Skikne 2000 Marine Flora Habitats Glossary Syllabus Students
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Plysiphnia Eclgy: Invasions