Kate F. Neill

Genetic diversity in Undaria pinnatifida (Laminariales, Phaeophyceae) deduced from mitochondria genes – origins and succession of introduced populations

S. Uwai, W. Nelson, K. Neill, W.D. Wang, L.E. Aguilar-Rosas, S.M. Boo, T. Kitayama and H. Kawai. 2006. Genetic diversity in Undaria pinnatifida (Laminariales, Phaeophyceae) deduced from mitochondria genes – origins and succession of introduced populations. Phycologia 45: 687–695. DOI: 10.2216/05-66.1 To elucidate the genetic diversity of the brown alga Undaria pinnatifida in native and introduced populations worldwide, and to discuss the transoceanic introduction processes, we investigated the haplotype divergence of the mitochondrial loci of the coding region of cox3 and noncoding region between tatC and tLeu genes. In its native range (Japan, Korea and China), we found 27 haplotypes, which were classified into 4 genetic and biogeographical groups: (1) Northern Japan type, distributed in Hokkaido and Pacific northern Honshu; (2) Continental type, found in Korea and China; (3) Pacific central Japan type; and (4) Sea of Japan type. Among the introduced populations, European and Mexican populations agreed with the Northern Japan type. In Australia, the Tasmanian population agreed with the Sea of Japan type, whereas the Victorian population was of the Continental type. Very high diversities were found in New Zealand: 10 haplotypes were found (including 2 only in old herbarium specimens), including both the Northern Japan type and the Continental type. The haplotype found in California agreed with a component of the Central Japan type collected at Kanagawa Prefecture. The samples from Argentina agreed with the Continental type. The alignment of the European populations with the Northern Japan type is consistent with the notion that the Undaria in Europe was first introduced with oyster spat. It is speculated that Californian and Mexican populations were recently introduced by shipping vectors. There have been many introduction events to New Zealand since the late 1980s, and the dominant haplotypes in the local populations appear to have changed over time. Introduction to Argentina/Australia (Victoria) could have resulted from secondary introductions from New Zealand populations, because transport within the same latitudinal range is considered to be easier than transport by shipping across the equator. Within Japan, the occurrence of both the Continental and the Northern Japan types in the Osaka Bay area is considered to be the result of recent intentional introduction for fisheries purposes.

Utility of psbA and nSSU for phylogenetic reconstruction in the Corallinales based on New Zealand taxa

A number of molecular studies of the Corallinales, a calcified order of the red algae, have used the conservative nSSU gene to investigate relationships within the order. However interspecific variation at this locus is low for closely related species, limiting resolution of recently diverged groups. In this study, we obtained psbA sequence data from specimens of the order from New Zealand that had been identified according to current taxonomic criteria. We compared phylogenetic analyses based on psbA with those based on nSSU for the same dataset, and also analysed nSSU sequences of the New Zealand material with nSSU sequences of Corallinales taxa from other parts of the world. Our study shows that psbA has considerable potential as a marker for this group, being easily amplified and considerably more variable than nSSU. Combined analyses using both markers provide significant support for relationships at both distal and terminal nodes of the analysis. Our analysis supports the monophyly of all three families currently defined in Corallinales: the Sporolithaceae, Hapalidiaceae and Corallinaceae, and indicates cryptic speciation in Mesophyllum and Spongites.

Ulva, Umbraulva and Gemina: genetic survey of New Zealand taxa reveals diversity and introduced species

The genetic diversity of the green algal genus Ulva sensu lato in the New Zealand region was surveyed, examining rbcL sequences of 581 samples from a wide geographical range. Twenty-four genetically distinct taxa were discovered in New Zealand waters, belonging to three genera–Ulva (19 species), Umbraulva (four species) and Gemina (one species). Of the 19 species of Ulva reported here, 13 could be identified to the species level based on morphological and genetic data. The remaining six species cannot currently be assigned to known species groups due to a lack of close homology with sequences in GenBank. These species may include undescribed endemic taxa, recognised taxa for which rbcL sequences are not yet available, or may represent cryptogenic species. The genus Umbraulva is recorded for the first time for the New Zealand region and for the Southern Hemisphere. Of the four species distinguished, one is considered to be introduced to the region and the other three are undescribed indigenous taxa. Subantarctic samples provide the first evidence of the genus Gemina since its description in 1952: sequence data confirmed that Gemina is distinct from Ulva and Umbraulva. A number of the species identified in this study can be distinguished through a combination of growth form, morphological, ecological and distributional characters. However there remain considerable problems in distinguishing a number of other species by morphological characters alone. Based on information such as distribution in New Zealand (percentage of samples occurring in highly modified environments and/or areas with frequent vessel traffic), as well as the genetic similarity of New Zealand samples to material from overseas, we have concluded that at least five species have been introduced to the New Zealand region: Ulva armoricana, U. californica, U. flexuosa, U. lactuca and Umbraulva olivascens.

Multi-gene phylogenetic analyses of New Zealand coralline algae: Corallinapetra Novaezelandiae gen. et sp. nov. and recognition of the Hapalidiales ord. nov.

Coralline red algae from the New Zealand region were investigated in a study focused on documenting regional diversity. We present a multi‐gene analysis using sequence data obtained for four genes (nSSU, psaA, psbA, rbcL) from 68 samples. The study revealed cryptic diversity at both genus and species levels, confirming and providing further evidence of problems with current taxonomic concepts in the Corallinophycidae. In addition, a new genus Corallinapetra novaezelandiae gen. et sp. nov. is erected for material from northern New Zealand. Corallinapetra is excluded from all currently recognized families and orders within the Corallinophycidae and thus represents a previously unrecognized lineage within this subclass. We discuss rank in the Corallinophycidae and propose the order Hapalidiales.

History, current status and future of marine macroalgal research in New Zealand: Taxonomy, ecology, physiology and human uses

New Zealand has a rich and diverse macroalgal flora that has been studied since James Cooks first voyage to New Zealand in 1769. The New Zealand region ranges from cool temperate seas at southerly latitudes to subtropical waters in the north. Here we review the history of phycological research in New Zealand since 1900, and the current status of research in taxonomy, ecology, physiology and seaweed uses including aqua‐culture and seaweed extracts. Some 770 species of seaweed are known to New Zealand, of which 22 are alien. Few taxa have received monographic treatment and many remain to be described. Polysaccharides have been identified from over 80 New Zealand seaweeds and many of these compounds have commercial potential. In addition to urgent taxonomic work, future research should include a national program of long‐term (> 5 years) monitoring of macroalgal communities, rates of growth and primary production, and the contribution of seaweed‐based production to coastal food webs.

Insights from natural history collections: analysing the New Zealand macroalgal flora using herbarium data

Abstract Herbaria and natural history collections (NHC) are critical to the practice of taxonomy and have potential to serve as sources of data for biodiversity and conservation. They are the repositories of vital reference specimens, enabling species to be studied and their distribution in space and time to be documented and analysed, as well as enabling the development of hypotheses about species relationships. The herbarium of the Museum of New Zealand Te Papa Tongarewa (WELT) contains scientifically and historically significant marine macroalgal collections, including type specimens, primarily of New Zealand species, as well as valuable exsiccatae from New Zealand and Australia. The herbarium was initiated in 1865 with the establishment of the Colonial Museum and is the only herbarium in New Zealand where there has been consistent expert taxonomic attention to the macroalgae over the past 50 years. We examined 19,422 records of marine macroalgae from around New Zealand collected over the past 164 years housed in WELT, assessing the records in terms of their spatial and temporal coverage as well as their uniqueness and abundance. The data provided an opportunity to review the state of knowledge of the New Zealand macroalgal flora reflected in the collections at WELT, to examine how knowledge of the macroalgal flora has been built over time in terms of the number of collections and the number of species recognised, and identify where there are gaps in the current collections as far as numbers of specimens per taxon, as well as with respect to geographical and seasonal coverage.

Recognition and distribution of Polysiphonia morrowii (Rhodomelaceae, Rhodophyta) in New Zealand

Abstract Polysiphonia morrowii, a species native to the North Pacific, is believed to have been introduced to Chile, Turkey, Italy and France. This species was first recorded from New Zealand in 2011, based on collections made in 2004 from two sites on South Island, but no commentary was provided in the distribution or characteristics of the material collected. In 2009, as part of a study on macroalgae associated with soft sediment habitats in New Zealand, several samples of P. morrowii were collected from Otago Harbour, a location already known to host 17 non-indigenous macroalgal species. However, this species has gone unnoticed in New Zealand. We present the current understanding of the distribution of this species in New Zealand, and the distinguishing features of the specimens collected, to assist with biosecurity and monitoring programmes. Including this report of P. morrowii, there are now seven species of Polysiphonia and Neosiphonia that are regarded as non-indigenous in New Zealand.

Northern New Zealand rhodoliths: assessing faunal and floral diversity in physically contrasting beds

Rhodolith beds are recognised internationally as unique ecosystems, harbouring a high diversity and abundance of marine biota. Beds typically occur in environments of moderate exposure and coarse sandy sediments, in which individual rhodoliths are not moved away from the beds, and do not get buried by fine sediments. For the first time in New Zealand, we have physically and biologically characterised selected rhodolith beds in order to document the marine biota within and beneath them. Three beds at two locations in the Bay of Islands, northern New Zealand, were sampled in February and September 2010; two beds were located in a typical rhodolith habitat (a sandy channel), and one in an atypical habitat (a muddy bay). In each bed, rhodolith species and abundance were analysed along with environmental characteristics (sediment granulometry, light environment, temperature, current speed and direction). Characterisation of biological diversity associated with the rhodolith beds included assessment of macroalgae, invertebrates (surface and subsurface) and fish. Sampling within the beds produced a total of 238 taxa: 197 invertebrates, 37 algal and four fish taxa, indicating that a high diversity of biota occur within these northern New Zealand rhodolith beds. We found significant differences in the abundance, taxon richness, and community structure of the biota among rhodolith beds, and surprisingly, the highest abundance and taxon richness occurred in a bed in a highly sedimented environment. In addition, two adjacent and physically similar beds were significantly different from each other in terms of community structure. This finding points to the importance of sampling individual rhodolith beds and suggests that it would be risky to extrapolate findings to other beds, even those in close proximity.

Macroalgal Diversity Associated with Rhodolith Beds in Northern New Zealand

Abstract The macroalgal flora associated with rhodolith beds in the Bay of Islands, northeastern North Island, was investigated as part of the first detailed study of subtidal rhodoliths in New Zealand. The rhodolith beds differed in their physical characteristics and in the dominant rhodolith-forming species present, one bed with clear water and predominantly Lithothamnion crispatum rhodoliths, and the other bed with turbid water, and Sporolithon durum rhodoliths covered by fine sediments. One hundred and three taxa were identified (12 green, 24 brown and 67 red algae), with similar numbers of taxa found in the two seasons sampled. The floral composition at the two beds differed significantly. The flora included range extensions for species previously reported within New Zealand (e.g. Cutleria multifida), new records for the New Zealand region (at family, genus and species levels — e.g. Dumontiaceae, Cutleria, Dictyota, Peyssonnelia spp), and new discoveries (e.g. Halymenia sp., Grateloupia sp., Tsengia sp.). Two species with a partially prostrate growth habit, Caulerpa flexilis and Chondracanthus chapmanii, were present in both beds consolidating rhodoliths and shell debris.

When seaweeds go bad: an overview of outbreaks of nuisance quantities of marine macroalgae in New Zealand

When large volumes of macroalgae wash up on beaches, accumulate in coastal areas or within confined bays, there can be significant local impacts. Blooms of macroalgae are being reported throughout the world with increasing frequency in estuarine and coastal areas in both temperate and tropical regions. This review examines examples of nuisance accumulations of macroalgae in New Zealand, the geographic and seasonal distribution of nuisance algal records, available data on impacts on coastal communities, including impacts on human activities, and considers some of the factors that may lead to excessive growth, as well as attempts to ameliorate the associated problems.