Sea Grant Final Report: Introduced Asiatic Porphyras: a C. Mathieson and C

Sea Grant Final Report: Introduced Asiatic Porphyras: A C. Mathieson and C. D. Neefus

Overview: As outlined in the synopsis of publications and theses resulting from our studies of non-native Porphyra taxa, multiple assessments of Northwest Atlantic seaweeds were employed (Mathieson, Pederson et al. 2008), including historical and recent floristic studies (Mathieson, Hehre et al. 2008), rapid assessment surveys (Mathieson et al. in press), molecular enumerations of cryptic seaweed taxa (Bray et al. 2006; Brodie et al. 2007; Neefus et al. in press), and morphological/ecological of evaluations (Nettleton 2008; Dare 2008). A total of four Asiatic taxa (i.e. Rhodophyta) were documented, including P. katadae A. Miura, P. suborbiculata Kjellman, P. yezoensis f. narawaensis A. Miura, and P. yezoensis f. yezoensis . The dates of their introductions, probable vectors, and sites of origins are summarized in Table I.

Methods: Molecular evaluations of rbcL and ITS-1 sequences were used to identify introduced Porphyra taxa between Long Island Sound and the Canadian Maritime Provinces (Bray 2006; Klein et al, 2003). Initially tissue samples were ground in a mortar and pestle; subsequently their genomic DNA was extracted using a Puregene Genomic DNA Purification kit. The ITS1-5.8S-ITS2 region was amplified using two primers- i.e. JBITS7 (Broom et al. 2002) and AB28 (Steane, 1991). The PCR reagents and amplification profiles were identical to those used by Teasdale et al. (2002). Prior to sequencing, the resulting amplicons were gel-purified to confirm their size and decrease non-specific or contaminating products (Klein et al. 2003).

The PCR amplified rbcL and ITS1 products were evaluated with an ABI 373 Automated Sequencer at the UNH Hubbard Center for Genome Sciences, using standard procedures outlined by Klein et al. (2003), Bray (2006), and Bray et al. (2006). Raw sequences were edited in Chromas (version 2.2, Technelysium, Pty. Ltd., Tewantin, Queensland, Australia). Contiguous sequence assembly and alignments were done in SeqMan II and MegAlign (version 5.08 for Windows, DNAStar, Inc., Madison, Wisconsin, USA), respectively. Searches of GenBank were conducted using Blastn via the Net Search option in MegAlign. Critical species identifications were confirmed by molecular comparisons of herbarium and recent collections (Bray, 2006; Bray et al. 2006), plus evaluations of GenBank accessions.

Results:

Species composition and distribution. Each of the four introduced Asiatic Porphyras may have been confused with one or more native species (cf. Brodie et al. 2007), including P. leucosticta Thuret in Le Jolis and P. rosengurttii Coll & Cox. Porphyra suborbiculata has small fronds and marginal spines, while P. katadae has sectored male and female blade segments like those found in P. purpurea (Bird and McLachlan, 1992). Reproductive plants of P. yezoensis often have pale marginal or distal streaks of spermatangia in between female gametangia (Miura, 1984). Thus, they look like P. leucosticata (Bird and McLachlan, 1992; Taylor, 1962). Porphyra katadae was the most recently discovered of the four Asiatic taxa (Bray et al. 2006), while the others probably occurred earlier and were not delineated until recent molecular evaluations of older herbaria samples. Several other previously undescribed Porphyras are present in the northwest Atlantic, as they have unique rbcL, SSU and ITS sequences (cf. Bray, 2006; Nettleton 2008).

Porphyra katadae has the most circumscribed distribution, occurring only at four sites near the north and south ends of the Cape Cod Canal. The two forms of Porphyra yezoensis exhibit varying distributional patterns, with f. narawaensis only occurring south of Cape Cod at seven sites (i.e. Massachusetts, Rhode Island and Connecticut), while f. yezoensis extends from mid-coastal Maine to the western end of Long Island Sound. The broader distribution of f. yezoensis than f. narawaensis suggests that at least two separate introductions of P. yezoensis have occurred. Further as f. narawaensis is a more recently developed cultivar than f. yezoensis the former is probably a later introduction than f. yezoensis (Mathieson, Pederson et al. 2008). The distribution of P. suborbiculata extends from Long Island Sound to at least Florida (Table 1), with a circumscribed occurrence in southern New England. Herbarium specimens of P. yezoensis f. yezoensis from Dover Point, New Hampshire date back to the mid-1960s when Reynolds (1971) identified it as P. leucosticta. In a recent molecular ecological study at the same site West et al. (2005) found no P. leucosticta, while P. yezoensis f. yezoensis was common from January-May. It is likely that the plant has been at Dover Point for 40 or more years and not distinguished from native species. In discussing the occurrence of P. yezoensis f. yezoensis at Dover Point, both West et al. (2005) and Bray (2006) ruled out the Eastport, Maine nori aquaculture operations (cf. Levine, 1998) as a source, as the rbcL sequence of its U51 cultivar differed by 2 bp (Klein et al. 2003) and it was f. narawaensis rather than f. yezoensis.

Historical and recent floristic assessments: Based upon early floristic studies in Casco Bay, Maine, Collins (1911) only found two introduced seaweeds, while 107 years later Mathieson, Hehre et al. (2008) found nine non-native taxa, including Porphyra yezoensis f. yezoensis. Thus, the number of introduced species from Casco Bay is now 4.5 times greater those previously recorded, including the occurrence of the Asiatic red alga P. yezoensis f. yezoensis. The more recent expansion (~40 years) of the same taxon at Dover Point should be recalled. Thus, floristic comparison and historical assessments are fundamental in determining the rates of expansion and potential impacts of introduced species.

Recent ecological and molecular studies: Nettleton (2008) recently documented the distribution and ecology of Porphyra yezoensis f. yezoensis and P. yezoensis f. narawaensis between New York and Downeast Maine. Populations of f. yezoensis were found at nine sites, including two beyond earlier documentations by Bray (2006), while P. yezoensis f. narawaensis occurred at four sites in Long Island Sound. Monthly density and biomass data were gathered along 20m transect lines at seven southern New England sites. Porphyra yezoensis f. yezoensis was not detected at two historic sites documented by Bray (2006), while the f. narawaensis had expanded to Cape Cod. Fucoid algae epiphytized by P. yezoensis demonstrated no stature reduction. Another cryptic Porphyra taxon, “P. stamfordensis” may be competing with P. yezoensis within western reaches of Long Island Sound.

Dare (2008) is presently finalizing molecular evaluations of diverse historical herbarium specimens of “Porphyra leucosticta”. The specimens were obtained from historical collections from the Hodgdon Herbarium (i.e. NHA) at UNH, as well as several other herbaria, including those of the Brooklyn and New York Botanical Gardens. The use of small DNA fragments has allowed her to evaluate many older historical specimens dating back more than 100 years. Such data will help to enumerate the occurrence of initial expansion patterns of diverse Asiatic taxa.

Publications and theses resulting from studies of introduced non-native Porphyra taxa from the Northwestern Atlantic:

Bray, T. L., C. D. Neefus, and A. C. Mathieson. 2006. Morphological and molecular variability of Porphyra purpurea (Roth) C. Agardh (Rhodophyta, Bangiales) from the Northwest Atlantic. Nova Hedwigia 82: 1-22.

Brodie, J., I. Bartsch, C. Neefus, S. Orfandis, T. Bray and A. Mathieson. 2007. New insights into the cryptic diversity of the North Atlantic- Mediterranean ‘Porphyra leucosticta’ complex”: P. olivii sp. nov. and P. rosengurtii (Bangiales, Rhodophyta). Eur. J. Phycol. 42: 3-28.

Dawes, C. J. and A. C. Mathieson. A review of invasive seaweeds. In Recent Advances on Applied Aspects of Indian Marine Algae With Refrence to Global Scenario, Vol. 3. . Ed. A. Tewari. Central Salt and Marine Chemical Research Institute, Bahavnagar, India (in press).

Mathieson, A. C., E. Hehre, C. J. Dawes, and C. D. Neefus. 2008.An historical comparison of seaweed populations from Casco Bay, Maine. Rhodora 110: 1-102.

Mathieson, A. C., J. Pederson and C. J. Dawes. 2008. Rapid assessment surveys of fouling and introduced seaweeds in the Northwest Atlantic. Rhodora (in press).

Mathieson, A. C., J. R. Pederson, C. D. Neefus, C. J. Dawes and T. L. Bray. 2008. Multiple assessments of introduced seaweeds in the Northwest Atlantic. ICES J. Mar. Sci. 65: 730-741.

Neefus, C. D., A. C. Mathieson, and T. L. Bray. 2008. The distribution, morphology and ecology of three introduced Asiatic species of Porphyra (Bangiales, Rhodophyta) in the Northwest Atlantic. J. Phycol. 44 (6). (in press).

Nettleton, J. C. 2008. Ecology, distribution, quantification, and impact of introduced, Asian Porphyra yezoensis f. yezoensis Ueda and Porphyra yezoensis f. narawaensis A. Miura in the Northwestern Atlantic. M. Sc. thesis, 87 pp.

Master’s theses:

Dare, S. 2008. A comparison of historical and recent collections of Porphyra leucosticta Thuret in Le Jolis. M. Sc. thesis, in preparation.

Reference Citations

Bird, C. J. and J. L. McLachlan. 1992. Seaweed Flora of the Maritimes 1. Rhodophyta- The Red Algae. Biopress Ltd., Bristol, England, 176 pp.

Bray, T. L. 2006. A molecular and morphological investigation of the red seaweed genus Porphyra (Bangiales, Rhodophyta) in the northwest Atlantic. Ph. D. Dissertation, University of New Hampshire, Durham New Hampshire, 165 pp.

Broom, J. E., W. A. Nelson, C. Yarish, W. A. Jones, R. Aguilar Rosas and L. E. Aguilar Rosas. 2002. A reassesment of the taxonomic status of Porphyra orbiculata, Porphyra carolinensis and Porphyra lilliputiana (Bangiales, Rhodophyta) based on molecular and morphological data. European Journal of Phycology 37: 227-236 .

Collins, F. S. 1911. The marine algae of Casco Bay. Proceedings of the Portland Society of Natural History 2: 257-282.

Humm, H. J. 1969. The Marine Algae of Virginia. University Press of Virginia, Charlottesville, 263 pp.

Klein, A. S., A. C. Mathieson, C. D. Neefus, D. F. Cain, H. A. Taylor, B. W. Teasdale, A. L. West, E. J. Hehre, J. Brodie, C. Yarish and A. L. Wallace. 2003. Identification of north-western Atlantic Porphyra (Bangiaceae, Bangiales) based upon sequence variation in nuclear SSU and plastid rbcL genes. Phycologia 42: 109-122.

Levine, I. 1998. Commercial cultivation of Porphyra (nori) in the United states. World Aquacultue 29: 37-47.

Mathieson, A. C., E. Hehre, C. J. Dawes, and C. D. Neefus. 2008.An historical comparison of seaweed populations from Casco Bay, Maine. Rhodora 110: 1-102.

Mathieson, A. C., J. R. Pederson, C. D. Neefus, C. J. Dawes and T. L. Bray. 2008b. Multiple assessments of introduced seaweeds in the Northwest Atlantic. ICES J. Mar. Sci. 65: 730-741.

Miura, A. 1984. A new variety and a new form of Porphyra (Bangiales, Rhodophyta) from Japan: Porphyra tenera Kjellman var. tamatsuensis Miura var. nov. and P. yezoensis Ueda form. narawaensis Miura form. nov. Journal of Tokyo University of Fisheries 71: 1-14.

Reynolds, N. B. 1971. The ecology of a New Hampshire estuarine tidal rapid. Ph. D. dissertation, University of New Hampshire, 101 pp.

Steane, D. A., B. A. McClure, A. E. Clarke and G. T. Kraft. 1991. Amplification of the polymorphic 5.8S rRNA gene from selected Australian Gigartinalean species (Rhodophyta) by polymerase chain reaction. Journal of Phycology 27: 758-762.

Taylor, W. R. 1962. Marine Algae of the Northeastern Coast of North America. University of Michigan Press, Ann Arbor, 509 pp.

Teasdale, B. W., A. West, H. Taylor and A. Klein. 2002. A simple restriction fragment length polymorphism (RFLP) assay to discriminate common Porphyra (Bangiophyceae, Rhodophyta) taxa from the northwest Atlantic. Journal of Applied Phycology 14: 293- 298.

West, A. L., A. C. Mathieson, A. S. Klein, C. D. Neefus and T. L. Bray. 2005. Molecular ecological studies of New England species of Porphyra (Rhodophyta, Bangiales). Nova Hedwigia 80: 1-24.

Table 1. Introduced Asiatic Porphyras found within the Northwest Atlantic.

Species Date and site of first observation, plus [present Mode of Probable known distribution] introduction* origin†

Porphyra katadae A. Miura ?2006, Cape Cod Canal, MA ?sh ?J,C

[Cape Cod Canal area]

Porphyra suborbiculata Kjellman ?1960s, Beaufort, NC ?sh NWP [as P. carolinensis J. Coll & Cox]

[Long Island Sound to Florida]

Porphyra yezoensis f.yezoensis Ueda1 1960s, Dover Point, NH ?sf J

[Maine to Long Island Sound]

Porphyra yezoensis f. narawaensis A. Miura2 >1960, Long Island Sound ?sf J

[Connecticut and Rhode Island]

1Porphyra yezoensis f. yezoensis was initially identified from the Northwest Atlantic from New Hampshire USA based upon molecular data (West et al., 2005) 2See Watson et al. (2000) and Bray (2006) in terms of farming of the U–51 strain of P. yezoensis f. narawaensis in Cobscook Bay, ME, USA. * Ship ballast (b), ship hulls (sh), seaweed endophyte (se), cultured shellfish (sf). † Australasia (AA); China (C); Europe (E); Japan (J); Northwest Pacific (NWP).