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PROJECTS
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Hawaiian Rhodophyta Biodiversity Project
We are underway with a 3-year, NSF-funded project to characterize the red algal biodiversity of the Hawaiian Islands (Co-P.I. Gernot Presting, Molecular Biosciences and Bioengineering, University of Hawaii). We are using a combination of DNA sequencing (3 regions) and morphological / anatomical investigations to assess collections from our own interisland field surveys, Bishop Museum, and expeditionary collections from our collaborators (the Census of Marine Life CReefs team, the Hawaii Undersea Research Laboratory deep water surveys, and the NOAA Coral Reef Ecosystem Division). Stay tuned for our internet-accessible database - the link will be active here in Summer 2008!
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 Selection of Hawaiian marine red algae |
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Biodiversity of Hawaiian freshwater algae
Although many different plant and animal groups have been well studied in Hawaii, only a handful of publications over the last 130 years have addressed the freshwater algal flora of these islands. Levels of endemism are known to be very high for some organisms, such as angiosperms and insects, but little is known about the degree of endemism for the freshwater algal flora, or its biogeographic origins. Amidst ongoing stream surveys of the Hawaiian islands, we are investigating the evolutionary relationships of selected algal species - among the different Hawaiian islands and through comparisons to material from possible colonization sources.
Relevant Publications: Sherwood, A.R. 2007. Where are we now regarding Hawaiian stream algal systematics? (A suspiciously cosmopolitan flora). Symposium on the Biology of Hawaiian Streams and Estuaries, April 2005, Bishop Museum Bulletin in Cultural and Environmental Studies 3: 195-206. Sherwood, A.R. 2006. Stream macroalgae of the Hawaiian islands: a floristic survey. Pacific Science 60: 191-205. Sherwood, A.R. & R.T. Nishimoto. 2005. Algal food preferences of the native Hawaiian fish, Sicyopterus stimpsoni (Osteicthyes: Gobiidae) in Hakalau Stream, Hawai‘i island. Ichthyological Exploration of Freshwaters 16: 97-106. Sherwood, A.R., Vis, M.L. & Sheath, R.G. 2004. Phenology and phylogenetic positioning of the Hawaiian endemic freshwater alga Batrachospermum spermatiophorum (Rhodophyta, Batrachospermales). Phycological Research 52: 193-203. Sherwood, A.R. 2004. Bibliographic checklist of the non-marine algae of the Hawaiian islands. Bishop Museum Occasional Papers Series 80: 1-23. Filkin, N.R., Sherwood, A.R. & Vis, M.L. 2003. Stream macroalgae of the Hawaiian Islands: 23 Additional Collection Sites. Pacific Science 57: 421-431. Sherwood, A.R. & Kido, M.H. 2002. Watershed-scale Comparisons of Algal Biodiversity in High Quality Proximate Hawaiian Stream Ecosystems. Pacific Science 56: 431-440.
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Systematics of Hawaiian Seaweeds
We are employing a combination of traditional microscopic techniques with powerful molecular analyses to examine the evolutionary relationships among selected groups of Hawaiian seaweeds. Research into the systematics of the Hawaiian Nemaliales has been completed in conjunction with Dr. Isabella Abbott and Dr. John Huisman. We are currently working with Dr. Celia Smith and her graduate student, Heather Spalding, to analyze the morphology, anatomy and molecular phylogenetic relationships of members of the Hawaiian deep water macroalgal flora.
Relevant Publications: Huisman, J.M., Sherwood, A.R. & Abbott, I.A. 2004. Studies of Hawaiian Galaxauraceae (Nemaliales, Rhodophyta): Large subunit rDNA gene sequences support conspecificity of Galaxaura rugosa and G. subverticillata. Cryptogamie, Alogologie 25: 337-352. Huisman, J.M., Abbott, I.A. & Sherwood, A.R. 2004. Large subunit rDNA gene sequences and reproductive morphology reveal Stenopeltis as a member of the Liagoraceae (Nemaliales, Rhodophyta), with a description of Akalaphycus gen. nov. European Journal of Phycology 39: 257-272. Huisman, J.M., Abbott, I.A. & Sherwood, A.R. 2004. The Liagoraceae (Nemaliales, Rhodophyta) of the Hawaiian Islands III: The genus Ganonema, with a description of Ganonema yoshizakii sp. nov. Phycologica 43: 296-310. Huisman, J.M., Sherwood, A.R. & Abbott, I.A. 2003. Morphology, reproduction, and the 18S rRNA gene sequence of Pihiella liagoraciphila gen. et sp. nov., (Rhodophyta), the so-called ‘monosporangial discs’ associated with members of the Liagoraceae (Rhodophyta), and proposal of the Pihiellales ord. nov. Journal of Phycology 39: 978-987.
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Phylogeography of native and alien seaweeds in Hawaii
Hawaii's coral reefs have been heavily impacted over the last several decades by a suite of newcomers to the flora. Building on preliminary ISSR data, we are using a combination of molecular and morphological tools to investigate the origins, dispersal, reproductive strategies and amounts of genetic variation in Acanthophora spicifera (funded by the Hawaii Coral Reef Initiative). We are using microsatellites to genotype populations throughout the Main Hawaiian Islands and are studying the phylogeographic patterns of the species across the Pacific (through DNA sequence comparisons) to better understand how this invasive species is able to spread so successfully in Hawaii, and to confirm purported sources of the Hawaiian plants. This information will aid resource managers in their decisions regarding mitigation measures, control techniques and importation regulations of alien invasive algae.
We are also interested in the phylogeographic patterns of species that have been long-recognized as native to Hawaiian waters. For example, a mitochondrial DNA analysis of the red seaweed, Asparagopsis taxiformis, revealed three distinct genetic lineages in the Main and Northwestern Hawaiian Islands, at least one of which is likely a recent introduction (within the last several decades). We are currently examining a number of other Hawaiian algal taxa in a similar manner.
Relevant Publications:
Sherwood, A.R. 2008. Phylogeography of Asparagopsis taxiformis (Bonnemaisoniales, Rhodophyta) in the Hawaiian Islands: two mtDNA markers support three separate introductions. Phycologia (in press).
O'Doherty, D. & Sherwood, A.R. 2007. Genetic population structure of the Hawaiian alien invasive seaweed, Acanthophora spicifera (Rhodophyta) as revealed by DNA sequencing and ISSR analyses. Pacific Science 61: 223-233.
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 Acanthophora spicifera (cystocarpic plant)
Asparagopsis taxiformis overgrowing coral on Maui (photo by Mark Vermeij)
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Impact of stream flow restoration on a Hawaiian stream system
A substantial proportion of Hawaii's 376 perennial streams are diverted, at least to some extent. This study is a remarkable opportunity to monitor the effects of a restored stream flow on the biological stream communities and the geomorphology of the stream itself. We are studying the stream algae of the Lalakea / Hiilawe watershed of Waipio Valley, Hawaii Islands, as part of a combined research team involving researchers from a variety of state agencies and mainland academic institutions. Other aspects of the biota being monitored include the aquatic invertebrates, fishes, and their parasites.
Project Website:
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Twin waterfalls at the back of Waipio Valley, Hawaii
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Systematics and Ecology of Subaerial Algae in Hawaii
We are studying the diversity, distribution and phenology of subaerial members of the green algal orders Trentepohliales and Cladophorales in the Hawaiian islands. Representatives of the genera Trentepohlia, Printzina, Phycopeltis and Cephaleuros, as well as a newly described genus and species in the Cladophorales (Spongiochrysis hawaiiensis), are being monitored in collaboration with Drs. Juan Lopez-Bautista and Fabio Rindi of the University of Alabama (Tuscaloosa).
Relevant Publications: Rindi, F., López-Bautista, J.M., Sherwood, A.R. & Guiry, M.D. 2006. Morphology and phylogenetic position of Spongiochrysis hawaiiensis gen. et sp. nov., the first known terrestrial member of the Cladophorales. International Journal of Systematic and Evolutionary Microbiology 56:913-922. Rindi, F., Sherwood, A.R. & Guiry, M.D. 2005. Taxonomy and distribution of Trentepohlia and Printzina (Trentepohliales, Chlorophyta) in the Hawaiian Islands. Phycologia 44: 270-284.
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Trentepohlia on Pandanus tree in Kahana Valley, Oahu |
