bluuebunny/crossref_metadata_2025 huggingface dataset:
165  The Chloroplast Genome of the Toxic Stramenopile Heterosigma Akashiwo (Raphidophyceae)
Authors: Veluppillai J. M. , Jacobs M. A. , Duplessis M. R. , Choi L. , Cattolico R. A.
Published: January 2004

Algae live in an informationally dense environment. To ensure survival, many phytoplankton species respond to specific environmental signals by alternating between motile vegetative and non‐motile resting life history phases. Heterosigma akashiwo (Raphidophyceae) can be induced to enter stasis by altering light, temperature and/or nutrient levels. In the resting phase, this obligate photoautotroph can survive for months in cold, dark coastal sediments. To understand how H. akashiwo modifies chloroplast function as it moves between life history phases, we want to (a) identify the signal transduction mechanisms and (b) transcriptional processes in this organelle. Sequencing the chloroplast genome represents the first step in this endeavor. Electron microscopy, reassociation kinetic analysis and restriction analysis show the Heterosigma chloroplast DNA to be 154 kb. Chloroplast DNA recovered by Hoescht dye/CsCl centrifugation has been sheared to 700 bp fragments, cloned in pUC19 and sequenced according to standard protocols. All Heterosigma chloroplast genes lack introns, some genes overlap, others contain large repeats. At least one gene encodes large (90–100 amino acid) domains that are inexplicably inserted within highly conserved proteins and finally, some chloroplast genes encode proteins that have an extended 5′ domain compared to homologues in other plastids. The Heterosigma genome has little co‐linearity with the stramenopile (Odontella), rhodophyte (Cyanidium, Porphyra), glaucophyte (Cyanophora), or cryptophyte (Guillardia) chloroplast DNAs that have been sequenced to date. Novel genes encoding signal transduction proteins have been identified.
166  Phylogeny of the Chlorophyceae: Inferences from the Chloroplast atpB Gene
Authors: Verghese B. , Buchheim M. A.
Published: January 2004

Phylogenetic reconstruction using the 18S and 26S rDNA genes has proven successful for many chlorophycean lineages, but some nodes remain poorly‐resolved. The chloroplast‐encoded atpB gene has been used to examine phylogenetic problems in several green algal lineages, including the basal streptophytes. However, data for other Chlorophyta are largely unavailable. The class Chlorophyceae, in particular, has not been examined (save for dense sampling among colonial and unicellular flagellates) using the atpB gene. An investigation of variability in the atpB gene for various chlorophycean exemplars was undertaken. Intergeneric distances (p) range from 0.08 (Chlamydomonas reinhardtii vs. Volvox carteri) to 0.24 (Haematococcus lacustris vs. Chloromonas radiata). Distance analysis also reveals high levels of divergence (as compared to the 18S and 26S rDNA data) for the family Sphaeropleaceae. Preliminary phylogenetic reconstructions fail to support a monophyletic Sphaeropleales, but this observation may be due to inadequate taxon sampling. The relative positions of other examplars (e.g., Chaetophora, Elakatothrix, Ascochloris) are largely consistent with interpretations of 18S and 26S rDNA data, although the position of Elakothrix is not robust. These preliminary observations suggest that the atpB gene will provide a powerful complement to current phylogenetic assessments of the Chlorophyceae using 18S and 26S rDNA data. Supported by NSF DEB 9726588 and DEB 0129030.
167  Algal Monitoring Studies on Remote Tropical Pacific Reefs
Authors: Vroom P. S. , Page K. N.
Published: January 2004

Coral reefs of US‐held islands in the central Pacific Ocean are among the most pristine in the world and represent over 93% of the reef systems under United States jurisdiction. The remote location of many islands has limited past algal research, resulting in incomplete understanding of species diversity, quantity, and ecology. Starting in 2000, the Coral Reef Ecosystem Investigation (CREI) began rapid ecological assessments on many Pacific island reefs to monitor ecological changes in reef biota over time. During the past year, algal efforts have concentrated on the French Frigate Shoals (Northwestern Hawaiian Islands) where we have increased the number of algal species reported by 1000%. Additionally, species new to science, including Acrosymphyton brainardii and Scinaia huismanii, have been described. Quantitative field sampling using a photoquadrat method is revealing species of the green algae Halimeda and Microdicyton to be ecological dominants in many areas during late summer/early autumn. Preliminary analyses with Primer software show species composition and abundance of all benthic organisms to differ significantly between most field sites sampled. Additional benthic habitat mapping of Pacific island reefs by CREI researchers is breaking the long‐held paradigm that macroalgal cover is minimal in healthy tropical reef systems. Videotape analyses of benthic communities often find over 50% algal cover from 1 to 20 meter depths in many locations. Common ratios of macroalgae, turf algae, and crustose coralline algae to corals, other benthic organisms and substrate types on US Pacific reefs are being calculated for the first time.
168  Cell Wall Proteomics of the Green Alga Haematococcus Pluvialis (Chlorophyceae)
Authors: Wang S. B. , Hu Q. , Sommerfeld M. , Chen F.
Published: January 2004

The green microalga, Haematococcus pluvialis, which can synthesize and accumulate large amounts of the ketocarotenoid astaxanthin, undergoes profound changes in cell wall composition and architecture during the cell cycle and in response to environmental stress. In this study, cell wall proteins (CWPs) of H. pluvialis were systematically analyzed by SDS‐PAGE coupled with peptide mass fingerprinting (PMF) and sequence‐database searching. In total, 163 protein bands were analyzed, which resulted in positive identification of 106 protein orthologues. The highly complex and dynamic composition of CWPs are manifested by the fact that the majority of identified CWPs are differentially expressed during specific stages of the cell cycle along with a number of common wall‐associated ‘housekeeping’ proteins. The detection of cellulose synthase orthologue in the vegetative cells suggested that the biosynthesis of cellulose occurred during primary wall formation. A transient accumulation of a putative cytokinin oxidase at the early stage of encystment pointed to a possible role in cytokinin degradation while facilitating secondary wall formation. This work represents the first attempt to use a proteomic approach to investigate CWPs of microalgae. The reference protein map constructed and specific protein markers obtained from this study provides a framework for future characterization of the expression and physiological functions of the putative proteins involved in the biogenesis and modifications of the cell wall of Haematococcus and other related organisms.
169  Cyanobacteria, Taxonomy and Aquatic Odour: Within‐ and Among‐Species Differences Re‐Examined
Authors: Watson S.B. , Kling H. , Izaguirre G.
Published: January 2004

Aquatic taste and odour (T/O) is most often associated with musty/earthy volatile organic compounds (VOCs) produced by cyanobacteria, the most‐studied taxa in T/O research. In fact although cyanobacteria represent over 200,000 described morphological species, relatively few (<characteristics. non‐robust apparently on based classification taxonomic to approach morphological traditional the re‐examine need underline also results These management and prediction odour for samples, field in taxa these of identification implications profound has This flasks. culture treatments same within even variable, highly fact are – coiling trichome shape, size akinete cell species this define currently which criteria key Several geosmin. compound production capita per morphology, differences intra‐strain inter‐marked show isolates ranges, natural representative levels over varied nutrients) temperature, light, (e.g. parameters major where conditions under variation productionn(c) VOC vitro their compares CA, Lake Castaic Ontario from lemmermanii Anabaena study a presents paper protocols. iv) culture; long‐term changes physiological undergone have or unconfirmed, is original whose strains, collection studies; iii) environment; growth with morphology; ii) misidentification; i) from: stem may ambiguity. Much treatment proactive development confounds Clearly, trait. robust not that suggest some sources, O T as confirmed been 0.025%)>.
17  Restoration Techniques For Nereocystis Luetkeana (Mertens) Postels Et Ruprecht (Bull Kelp)
Authors: Carney L. T.
Published: January 2004

The establishment and growth of Nereocystis luetkeana communities are limited by many environmental and biotic factors. Temperature, light quantity and quality, turbidity, salinity, wave motion, and competition for space and light all determine where populations of this annual kelp will establish and persist from season to season. Like much of the nearshore marine vegetation in Puget Sound and the San Juan Archipelago, Nereocystis is negatively impacted by anthropogenic disturbances, such as shoreline development and sediment loading from terrestrial erosion. These events can alter or eliminate optimal habitat and conditions that support adult populations, as well as interfere with the development of the microscopic life stages. Various techniques to establish a Nereocystis bed in the northern waters of Washington, USA are examined and will serve as a model for future restoration efforts. Techniques being investigated are as follows: 1) out‐planting Nereocystis during different seasons; 2) out‐planting at different stages of maturity, i.e., zoospore and microscopic sporophyte (0.5–1.0 mm blade length) from cultures; 3) out‐planting directly on natural substratum versus at elevated positions; 4) transplanting juveniles (10 cm stipe length); and, 5) seeding natural substratum with out‐planted sori (sporophylls), bypassing the lab culturing phase. Results of this study will help define the optimal restoration procedure, including environmental parameters, for Nereocystis in order to aid coastal managers in the implementation of nearshore restoration projects. Preliminary results will be presented.
18  Morphology, 16s rRNA gene sequences, and internally transcribed (ITS) regions: towards a meaningful systematic framework for the cyanobacteria
Authors: Casamatta D. A. , Johansen J. R.
Published: January 2004

Cyanobacterial systematics is currently in a state replete with confusion. Many systematic frameworks have been proposed to varying degrees of success. Traditional designated clades (e.g., Chroococcales and Oscillatoriales) have been shown to be polyphyletic, and do not truly reflect evolutionary histories. Recently, however, research has identified some phylogenetically informative characters at the familial level based on morphological characters. The 16S rRNA gene sequence has been advocated as the gold standard for systematic assignment of members of this clade, although the utility of this gene at assigning higher level taxonomy and species level designations remains questionable. We propose a three pronged approach to cyanobacterial systematics. First, the use of thylakoid arrangement and type of cell division is useful at the familial level. Next, 16S rRNA gene sequence data can be used to assign generic placement and together with morphology is sufficient for recognition of separate species. Third, the secondary folding structure of the 16S‐23S rRNA internally transcribed spacer region provides an excellent tool for species level assignments by providing recognizable autapomorphies. We have employed these characters in the analysis of 25 members of the Oscillatoriales, and obtained an excellent degree of resolution and stability in their systematic placement. Taken together, we feel this combined approach can lead to an accurate assessment of cyanobacterial phylogeny and taxonomy in the context of the autapomorphic phylogenetic species concept.
19  Periphytic algae as bioindicators of nitrogen inputs in lakes
Authors: Cascallar L. , Mastranduono P. , Mosto P. , Rheinfeld M. , Santiago J. , Tsoukalis C. , Wallace S.
Published: January 2004

Increased nitrogen levels has been shown to be a problem in Southern New Jersey lakes, with anthropogenic loadings being the most serious concern (Aber, 1992). It has been suggested that biomass, diversity, and community structure of periphytic algae are good biotic indicators for monitoring water quality and nutrient enrichment in fresh water lakes. (Biggs, 1989). Since, for algae and many other aquatic organisms, nitrogen is one of the most important factors for growth, a good correlation it is expected between nitrogen loading and algal growth. In this bench‐scale microcosm study the periphytic community was analyzed using chlorophyll a, dry‐ash weight biomass and cell counts, as well as the diversity and community structure for a six‐month period, in three tanks with different nitrogen levels (control=non‐detectable; low and high). Physical (T/DO/pH) and chemical (nutrients) parameters were measured monthly. Biological parameters were compared with the different nitrogen loading using correlation analysis to show whether nitrogen is a factor in the over‐enrichment of New Jersey lakes. To compare the bench‐scale microcosm study with the natural settings periphytic algae from two Southern New Jersey lakes, Oswego Lake (no nitrogen) and Oakford Lake (high nitrogen), were also collected during fall of 2002 to summer of 2003.
2  Influence of mixed host populations on success of the parasitic dinoflagellate Amoebophrya
Authors: Armstrong T.‐N. , Felton C. , Coats D. W.
Published: January 2004

Parasitic dinoflagellates of the genus Amoebophrya commonly infect bloom‐forming dinoflagellates of Chesapeake Bay, including Akashiwo sanguinea and Karlodinium micrum. While different strains of Amoebophrya appear host specific, infective dinospores liberated from A. sanguinea do enter the cytoplasm of K. micrum, but fail to complete the infection cycle. Thus, in mixed‐species dinoflagellate blooms, interference from inappropriate hosts may influence the success of Amoebophrya spp. To explore that possibility, we conducted laboratory studies to examine the effect of the toxic dinoflagellate K. micrum on success of Amoebophrya from A. sanguinea. Treatments consisted of A. sanguinea (1000/mL) plus corresponding dinospores (10,000/mL) in the presence of different K. micrum densities (0 to 100,000/mL). We also examined whether changes in parasite success were due to interaction with K. micrum cells, or from indirect effects of bacteria or dissolved substances present in K. micrum cultures. Success of Amoebophrya was unaffected by low densities of K. micrum, but decreased at high concentrations of K. micrum. Reduced parasite success appeared to result from combined effects of non‐host cells and dissolved substances in K. micrum media. Results suggest that parasitism of A. sanguinea in Chesapeake Bay would be reduced when K. micrum is a major component of mixed‐species blooms.
20  Chloroplast signal transduction in heterosigma akashiwo
Authors: Cattolico R. A. , Jacobs M. A. , Velluppillai J. M. , Adman E.
Published: January 2004

Maintenance of homeostasis requires that an organism perceive selected physical and chemical signals and convert this information via signal transduction pathways into an appropriate metabolic response. The Heterosigma chloroplast genome encodes the regulatory protein of a His/Asp signal transduction system. This two‐ component system, which is also found in prokaryotic cells, allows the organism to selectively modify chloroplast gene transcription in response to environmental cues. Using artificially created 50 base oligomeres in a TRG1‐DNA binding assay, it was determined that this regulatory protein recognized the 6‐base consensus sequence TTAGGT. Analysis of 27 sequenced Heterosigma chloroplast genes revealed that this six ‐base motif was found almost exclusively in genes associated with photosystem II, Calvin cycle and energy generation functions with high statistical probability‐ suggesting that TRG1 may be a global regulator of this gene set. Molecular modeling has shown that the Heterosigma TRG1 protein with the sigma 70 subunit of eubacterial‐like RNA polymerase which we know from sequencing data to be chloroplast localized in Heterosigma. Antibodies generated against TRG1 showed no change in the concentration of this protein when vegetative Heterosigma cells were maintained on a 12 h light:12 h dark photoperiod or during resting cell biogenesis. This observation suggests that TRG1, like its bacterial counterparts, is regulated by phosphorylation. The presence of a His/Asp two‐component signal transduction pair in the chloroplast genome is taxon‐specific.
21  Differential screening and suppression subtractive hybridization identifies genes differentially expressed in male and female plants of aglaothamnion oosumiense (rhodophyta)
Authors: Chah O. K. , Kim G. H.
Published: January 2004

Sex determination and development of reproductive structures in Aglaothamnion oosumiense were examined by cytogenetic and molecular studies. Chromosome studies of male and female reproductive cells indicated that the sexuality of this species might be determined by a sex chromosome. Chromosome counts in female and male gametophytes were 37 and 36, respectively. The sex ratio of the gametophytes was 1:1. Also male‐derived bisexual plants were observed. They were different in morphology, position of carpogonial branches and chromosome number. Some male plants also developed parasporangia. Chromosome number of the paraspore germlings was the same as in the male plants. A novel method combining element of suppression subtractive hybridization (SSH) with high throughput differential screening permitted an efficient and rapid cloning of rarely transcribed differentially expressed genes. Potential of the method is demonstrated by the isolation of 212 subtractive clones that were differentially expressed in male and female plants. About 18 subtractive clones were confirmed by reverse northern blotting. Two genes, AOMS‐1 and AOMS‐2, which showed male specific expression were analyzed. These genes seem to be involved in differentiation of male reproductive structures.
22  Nutrient use efficiency and coastal productivity: comparative perspectives on ecosystem structure and mechanisms of control
Authors: Chan F. , Menge B. A. , Nielsen K. , Lubchenco J.
Published: January 2004

Net primary production in marine ecosystems ultimately reflects the inputs of nutrients and the efficiency with which nutrients are acquired and used by phytoplankton in growth. In contrast to our understanding of the linkages between nutrient loading and production, the influence of nutrient use efficiency (NUE) on cross‐system variations in coastal productivity remains unclear. Nutrient use efficiency at the ecosystem scale is the product of the per capita efficiency of nutrient use in phytoplankton growth and the efficiency with which phytoplankton communities are able to assimilate limiting nutrient(s). We measured the relative dominance of ecosystem N pools by phytoplankton biomass as an index of NUE across 56 inner‐shelf sites. These sites were distributed across a strong geographic range of upwelling intensity and productivity along the coasts of Oregon, California and New Zealand. We also compiled an extensive dataset of published NUE values in coastal and oceanic sites in order to assess cross‐system patterns and differences in NUE. Our results indicate that exceptional rates of productivity in inner‐shelf upwelling systems arise as a consequence of near dominance of ecosystem N pools by phytoplankton biomass. Elevated rates of NUE nevertheless appear to be a transient phenomenon in marine systems. Cross‐shelf transects across upwelling fronts off the Oregon coast reveal a temporal pattern of intense phytoplankton blooms and decline that reflects the eventual dominance of ecosystems N pools by detrital and dissolved organic N pools. Our findings suggest that NUE may play a central role in governing the productivity of marine ecosystems.
23  Phylogenetic position of Alaria Fistulosa (laminariales, phaeophyceae) based on nuclear its and plastid coding genes
Authors: Cho G. Y. , Yoon H. S. , Klotchkova N. G. , Hansen G. I. , Boo S. M.
Published: January 2004

Alaria is a common kelp genus generally found in the lower intertidal and shallow subtidal regions of rocky shores in the cold waters of the northern Hemisphere. About 16 species are currently recognized worldwide and, of these, A. fistulosa is distinguished by having hollow midrib and large blades with 10–30 m in length and 30–90 cm in width. It is the only canopy‐producing kelp in the northwest Pacific, where it is restricted to the waters of north Hokkaido, Kamchatka, Aleutian Islands, and Alaska. In order to know the phylogenetic position of A. fistulosa, sequences of nr DNA ITS and plastid rbcL including spacer and psaA regions were determined in A. fistulosa and compared with homologous positions of newly sequenced putative relatives and with published sequences of other kelp species. Combined data of ITS and Rubisco spacer show that A. fistulosa was more related to the clade of Lessoniopsis and Pterygophora than to the clade of other species of Alaria, which is supported by the rbcL and psaA sequence data. The topologies from nuclear and plastid DNA sequences lead to phylogenetic independence of A. fistulosa, which is clearly different from the genus Alaria.
24 Diversity of macroalgal epiphytes on Thalassia and Syringodium in tampa bay, florida
Authors: Cho T. O. , Fredericq S.M , Yates K.
Published: January 2004

Blooms of seagrass epiphytes have potentially important economic and ecological consequences in Tampa Bay, one of the Gulf of Mexico's largest estuaries. As part of a Tampa Bay Study to monitor the impact of environmental stresses, we are characterizing epiphyte diversity for efficient management of affected resources for assessment of ecosystem health. We have collected green, brown an red algal epiphytes on Thalassia testudinum and Syringodium filiforme from fixed monitoring sites at Bishop Harbor, Cockroach Bay, Feather Sound, and from dense and sparse Thalassia testudinum and Syringodium filiforme seagrass bed sites at Mariposa Key and north of Port Manatee. A main goal of this ongoing study is the determination of indicator species for both healthy and stressed seagrass bed environments.
25  Proposal of a new red algal genus in the ceramieae (ceramiaceae, ceramiales)
Authors: Cho T. O. , Fredericq S. , Hommersand M. H. , Boo S. M.
Published: January 2004

A new genus is proposed to accommodate four species belonging in the Ceramium flaccidum complex based on comparative vegetative morphology and rbcL sequence analysis: C. flaccidum (Harvey ex Kuetzing) Ardissone (1871), C. gracillimum, C. Agardh (1824), C. fimbriatum S. & G. (1924) and C. rectocorticum Dawson 1950. Comparative rbcL sequence analysis indicates that this complex forms a distinct monophyletic clade separate from other Ceramium species. Although C. flaccidum has been placed in Hormoseras Kuetzing 1841 (as H. flaccidum Harvey ex Kuetzing 1862), the type species of Hormoceras is Ceramium diaphanum. The new genus is characterized by alternate branching, incomplete cortication, production of three cortical filament initials of which the basipetal initial divides horizontally, and unicellular rhizoids terminating in pad‐like structures produced from periaxial cells. Cortical filament development is discussed for related genera in the tribe Ceramieae (Campylaephora, Carpoblepharis, Centroceras, Ceramium, Corallophila, Herpochondria, Microcladia, Reinboldiella). RbcL‐based phylogenies indicate that the new genus is sister to Centroceras, a genus possessing three cortical filament initials. The phylogenetic relationships within the tribe may correlate with cortication patterns that characterize each genus
26  Development of the cultivation of Laminaria Saccharina as the extractive inorganic component of an integrated aquaculture system and monitoring of therapeutants and phycotoxins
Authors: Chopin T. , Bastarache S. , Belyea E. , Haya K. , Sephton D. , Martin J. L. , Eddy S. , Stewart I.
Published: January 2004

The development of sustainable integrated aquaculture systems requires combining fed aquaculture (finfish) with extractive inorganic aquaculture (seaweed) and extractive organic aquaculture (shellfish). With the support of AquaNet, the Network of Centers of Excellence in Aquaculture in Canada, we are developing such a system at an industrial pilot scale by co‐cultivating salmon (Salmo salar), kelp (Laminaria saccharina) and blue mussel (Mytilus edulis) at aquaculture sites in the Bay of Fundy, Canada. This presentation will focus on the development of the extractive inorganic component. The entire cycle of rearing Laminaria saccharina has been completed and improved, both in the laboratory and at the integrated sites: release in the laboratory of spores from mature macroscopic sporophytes, seeding of ropes, germination of microscopic gametophytes, sexual maturation of male and female gametophytes, development of zygotes into juvenile sporophytes, which are then transplanted to the sites for rapid grow‐out. Another aspect of the project, food safety monitoring of chemical therapeutants and phycotoxins in mussel and kelp cultured in proximity to salmon, will also be described. The productivity, nutrient absorption capacity, and role of the seaweed component are being analyzed so that its appropriate scale to the other components can be defined in order to develop responsible aquaculture practices in which metabolic/physiological processes of the different co‐cultured organisms counter‐balance each other within acceptable operational limits. Adopting polytrophic strategies will be key to the aquaculture industry to develop its environmentally and economically‐balanced diversification and increase its social acceptability within a broader coastal management framework.
27  Spatiotemporal distribution of abundance and density of calcareous green macroalgae along the florida keys: a synchrony study
Authors: Collado‐vides L. , Rutten L. , Fourqurean J.
Published: January 2004

Discerning patterns of spatiotemporal variation in wide areas is a basic step in understanding changes on coastal communities. Spatial autocorrelation or spatial synchrony (i.e. how populations covary in abundance over time) provides helpful information from population dynamics that allow us to detect common trends of variation at different spatial scales. In this study we describe the spatial and temporal variation of five calcareous green macroalgae, and analyze the synchrony of abundance and density of the five genera separately and as a functional‐group along the Florida Keys. For this study we are using data from thirty sites that have been quarterly monitored since 1996. Abundance and density of seagrass and macroalgae have been recorded using a Braun‐Blanquet methodology for the Seagrass monitoring program. We found that each genus has a distinct spatiotemporal distribution, different to the group distribution. We evaluated synchronous changes in abundance and density over time at different space scales; we found that synchrony was high between patches and lower between distinct geographical areas; and each genus showed its own synchrony pattern which was obscured when analyzed as a group. We compared the results from functional‐group to individual genus analyzing the validity of the use of functional‐groups for monitoring programs. We discuss the role of synchrony in the selection of genera for a functional‐group.
28  Lipid composition of members of the algal class chlorarachniophyceae
Authors: Dahmen J. L. , Leblond J. D. , Chapman P. J.
Published: January 2004

The algal class Chlorarachniophyceae is comprised of a small group of unicellular eukaryotic algae that are often characterized by an unusual amoeboid morphology. This morphology is hypothesized to be the result of a secondary endosymbiosis in which a green alga was engulfed as prey by a nonphotosynthetic amoeba or amoebaflagellate. Whereas much is known about the phylogenetic relationships of individual chlorarachniophytes to one another, and to possible ancestral host organisms in the genera Cercomonas and Heteromita, little is known about their physiology, particularly that of their lipids. In an initial effort to characterize the lipids of this algal class, seven organisms were examined for their fatty acid and sterol composition. These included Bigelowiella natans, Chlorarachnion globusum, Chlorarachnion reptans, Gymnochlora stellata, Lotharella amoeboformis, Lotharella globosa, and Lotharella sp. Fatty acids associated with chloroplast‐associated glycolipids, cytoplasmic membrane‐associated phospholipids, and storage triglycerides were characterized. Glycolipid fatty acids were found to be of limited composition, containing principally eicosapentaenoic acid [20:5(n‐3)] and hexadecanoic acid (16:0), which ranged in relative percentage from 67–90% and 10–29%, respectively, in these seven organisms. Triglyceride‐associated fatty acids were found to be similar. Phospholipid fatty acid composition was more variable. The principal phospholipid fatty acids, 16:0 (25–32%) and a compound tentatively identified as docosapentaenoic acid [22:5(n‐3)] (26–35%), were found along with a number of C18 and C20 fatty acids. All organisms contained two sterols as free sterols. These were tentatively identified as 24‐ethylcholesta‐5,22E‐dien‐3b‐ol (stigmasterol; 70–95%) and 24‐methylcholesta‐5,22E‐dien‐3b‐ol (brassicasterol; 5–30%).
29  Pin the part on the dinoflagellate: a hands on learning activity
Authors: Dalpra D. , Kirkpatrick B. , Fleming L. E.
Published: January 2004

Marine science education often uses animals with high student appeal, such as manatees, sea turtles, whales and dolphins, to introduce science concepts. The challenge in teaching microalgae concepts is to make the activity as equally appealing and engaging to students. The activity created used an enlarged diagram of a marine dinoflagellate, Karenia brevis, to introduce anatomy and function concepts. The activity was simple in design requiring only a large color diagram of the organism, laminated for durability and hook and loop fastener for placement of parts in the appropriate area. Because of its simplicity in design, the activity is inexpensive can be easily reproduced. Key words were also created and laminated to reinforce vocabulary. This activity was found to reach a wide age range from elementary school students to high school. The facilitator could adjust the prompts to assist the students in the proper labeling based on age. At the elementary level, basic anatomy such as nucleus and flagella could be introduced. At the middle school level, labeling of the chloroplasts could lead the discussion to photosynthesis and the food web, and at the high school level the discussion could be focused toward primary productivity and harmful algal blooms. The concepts taught in this activity easily address many key points in the National Science Education standards such as structure and function of living systems and diversity and adaptation of organisms. This activity could easily be adapted to numerous algal organisms in both the marine and freshwater environments.
3  Phylogenetic affinity of the palmelloid green algae, verdigellas and palmophyllum (chlorophyta), based on analyses of nuclear‐encoded small subunit rDNA sequences
Authors: Ashworth M. P. , Spalding H. L. , Hanisak M. D. , Fawley M. W. , Buchheim M. A. , Zechman F. W.
Published: January 2004

Palmophyllum, Verdigellas and Palmoclathrus are marine palmelloid green algae with morphologies ranging from closely adherent crusts, peltate discs, to upright branched thalli. Thalli of these taxa are comprised of small spherical cells embedded within a dense mucilaginous matrix. Taxonomic affinities of these palmelloid genera, however, has remained uncertain. Previous studies of Palmophyllum and Verdigellas classified these algae within the Palmellaceae, but the complete absence of data regarding reproduction have blurred ordinal designations. Generally, these algae have been classified as members of the Tetrasporales within the class Chlorophyceae, but the Chlorococcales has also been proposed. Global analyses of eukaryotic nuclear‐encoded small subunit rDNA sequences based on parsimony (MP), neighbor joining (NJ) and likelihood (ML) methods confirm the placement of Palmophyllum and Verdigellas as a monophyletic group within the Chlorophyta, but class and ordinal affinities were not clearly resolved. ML suggested that Verdigellas and Palmophyllum are members of a clade with coccoid prasinophyte algae at the base of the Chlorophyta, while NJ and ML suggested that the palmelloid genera formed a basal lineage of the Viridiplantae. A consistent feature of all analyses, however, is that Verdigellas and Palmophyllum did not group with the chlorophycean orders, Tetrasporales or Chlorococcales. Results will be discussed in the context of taxonomy, character evolution, and implications for green plant evolution. (Supported in part by NSF grants DEB‐0128952 to MWF, DEB‐0129030 to MAB, and DEB‐0128977 to FWZ)
30 Seasonal control of phytoplankton biomass and productivity in coastal british columbia lakes and reservoirs
Authors: Davies J. M. , Nowlin W. H. , Mazumder A.
Published: January 2004

Factors controlling algal abundance and carbon fixation form a cornerstone of aquatic ecology. Central among these are light, nutrients, and grazers. We measured 14C fixation over one year in six coastal BC lakes that differed in trophic status and grazer community structure. The lakes in our study were never covered with ice, so mixing due to wind energy was more similar to summer months and light levels were higher during winter than comparable ice‐covered lakes. Our study, therefore, offered a unique opportunity to examine how seasonal changes in light and temperature affects the functioning of these lakes. While many of our study lakes had higher chlorophyll concentrations during winter months, only the lake with a community dominated by small grazers maintained moderate nutrient deficiency throughout the year and increased 14C‐fixation during the winter (Jan–Feb).
31  Effects of light and ammonium on growth, ammonium uptake and pigmentation of four porphyra (bangiales, rhodophyta) species native to the northwestern atlantic
Authors: Day J. P. , Neefus C. D. , Kraemer G. P. , Yarish C. , Chopin T.
Published: January 2004

The marketability and physiological characteristics of Porphyra (nori) make it a good candidate for integrated aquaculture. Four species were grown in separate three‐week greenhouse trials via tumble culture in small tanks (38L). Porphyra umbilicalis, P. linearis, P. leucosticta and P. amplissima were grown at 15, 8, 15 and 12 C, respectively. Plant growth, ammonium uptake, and pigment content were evaluated at three light levels (4%, 13%, and 58% of ambient sunlight), and two ammonium concentrations (25 and 250 ?M). The growth of Porphyra umbilicalis was higher at 250 ?M than at 25 ?M ammonium (P?0.002), while growth of the other three species were not affected by nitrogen concentration (P>0.05). With the exception of P. leucosticta, plant growth was greatest in high light (58% of ambient). Overall, average growth rates ranged from 31.8 (±2.8)%·day‐1 for P. amplissima to 8.8 (±1.2)%·day‐1 for P. leucosticta. Ammonium uptake rates were consistently higher in 250 than 25 ?M ammonium (P?0.05), except for P. amplissima (P>0.05). Uptake by P. umbilicalis was greatest at high light (P<0.005), but light did not affect uptake rates in the other three species (P>0.05). The phycoerythrin content of P. umbilicalis and P. leucosticta was greater at 250 ?M than 25 ?M ammonium, while it was not affected by nitrogen level in P. linearis and P. amplissima. The phycoerythrin content of all species decreased from low to high light (P<0.05); however, light affected the net phycoerythrin production only in P. leucosticta.
32  Phytopia: an educational cd‐rom to explore the bottom of the food web
Authors: Decharon A. V. , Mcdonnell wysor T. A. , Sieracki M.
Published: January 2004

“Phytopia: Discovery of the Marine Ecosystem” is an educational CD‐ROM that features a wealth of new images, animations, microscope‐ and satellite‐derived data sets, and multimedia discovery tools. It has received support from NASA and the National Science Foundation and can ordered on‐line through http://www.bigelow.org/phytopia. A pre‐release version of the “Phytopia” was tested by students, educators, and scientists at 34 institutions in Britain, Germany, Russia, and throughout the U.S. This product is designed for use in undergraduate classes; however, our testing has shown that it provides an exciting and interactive learning experience appropriate for Grades 7 and higher. The virtual microscope tool allows the user to view prepared assemblages of plankton at various magnifications, under different epifluorescence conditions, or by scanning electron microscopy. For several species, the user can view movies showing the organism's motility. Some species are featured as three‐dimensional models that can be viewed from any perspective. “Phytopia” also helps users connect ocean primary productivity patterns with environmental factors in several geographic areas. Innovative tools allow investigation of co‐registered temperature, wind, current, nutrient, and ocean color data. This tool is aligned with research efforts to better understand plankton ecology using remotely sensed data.
33  Boron in diatoms
Authors: Deyhle A. , Hodge V. , Lewin R. A.
Published: January 2004

Lewin, J. C. (1965) showed that boron is required for the growth of Cylindrotheca fusiformis, and, presumably, other diatoms too. It may be involved in cellular metabolism, as in higher plants, or incorporated by accident or design into the siliceous skeletons (frustules), since B2O3 has been proven to replace SiO2 (e.g. in siliceous rocks). Thus the frustules may contain or bear at their surface a proportion of borosilica, which might reduce their solubility in water. (Incidentally, boron has also been implicated in human bone formation and stability (Newnham, 1994). Deyhle (2002), who determined the content of B in calcareous skeletons of marine foraminifera and compared the isotopic ratios of 11B/10B with that in the environmental sea water, found the B content to be generally less than 10 ppm We sought comparable values for diatom frustules, washed and bleached to remove salts and organic matter, if possible without leaching away any of the B that could be present. We studied fossil diatomite from Lompoc, California; diatomaceous ooze from Myvatn, Iceland; natural plankton diatoms harvested from the sea; and pure cultures of marine and freshwater diatoms grown in the laboratory. By contrast with foraminiferan calcite, our data indicated that diatom frustules contain up to 1,600 ppm of boron, with a more marked enrichment of the lighter isotope. Rough calculations indicate that the B2O3, even if concentrated at the frustule surface, might be enough to reduce the solubility of the frustules. Our B‐isotope enrichment data range between +3.9 to −0.2‰, indicating that diatoms preferentially incorporate the light 10B. Such values can provide indications to physico‐chemical conditions under which the skeletons were deposited (cf. Lewin, E. et al. 2000) Data will be presented.
34  Pieces of a puzzle: biogeography of southeast farallon Island, California
Authors: Dickey K.
Published: January 2004

Rocky intertidal communities in cold waters on open shores tend to have a stable, predictable makeup worldwide. The structure of the environment, the morphology and life history of species, the economics of species behavior and the dynamics of population changes all contribute to the distribution of species in a given habitat. South East Farallon Island, in the Pacific Ocean off the northern California coast, hosts an intertidal community typical in many ways of other rocky intertidal communities. However, two orders of marine algae one might expect to be there, the Fucales and Laminariales, are unexpectedly uncommon on this island. In this paper some of the possible environmental, morphological and life history factors contributing to and restricting the distribution of marine algae in the intertidal zone on South East Farallon Island are considered.
35  Diversity and distribution of fusiform microchlorophyte algae from itasca state park, minnesota, and arrowwood national wildlife refuge, north dakota
Authors: Dimmer Stephanie K. , Fawley M. W. , Fawley K. P.
Published: January 2004

Several types of fusiform microchlorophyte algae (Monoraphidium, Ankistrodesmus, and related genera) have been characterized from lakes and ponds of Itasca State Park, Minnesota, and Arrowwood National Wildlife Refuge, North Dakota. PCR‐RFLP analysis of 18s ribosomal RNA genes was used to categorize 29 different isolates from Itasca State Park into 9 different types, and 15 isolates from the Arrowwood National Wildlife Refuge samples into 8 different types. 18S ribosomal DNA sequences were determined for at least one isolate from each type for phylogenetic analysis. All of these sequences were different than any sequence published in GenBank. None of the types were found in both Itasca State Park and Arrowwood National Wildlife Refuge. These results suggest that fusiform green algae are highly diverse, with little species overlap in different habitats.
36  Nutrients and harmful algal blooms: general issues and examples from the northern gulf of mexico
Authors: Dortch Q.
Published: January 2004

Nutrient inputs have increased worldwide in both marine and freshwater ecosystems, stimulating algal growth. The resulting increased eutrophication can be manifested in different ecosystems as hypoxia/anoxia, loss of submerged aquatic vegetation, or Harmful Algal Blooms (HABs). HABs can significantly impact human and ecosystem health. It has been hypothesized that HABs are increasing worldwide, in part because of increasing nutrient inputs, but establishing a direct cause and effect link has been difficult for a variety of reasons. Two examples from the Louisiana coastal zone illustrate some of the difficulties and successes: annual Pseudo‐nitzschia spp. blooms on the shelf in the extended plume of the Mississippi River and sporadic, toxic cyanobacterial blooms in low salinity estuaries. The challenge is to determine if a HAB is caused by increased nutrient inputs and which nutrient(s) are the main culprit(s), to identify the source(s) of the increased nutrients, and to develop effective management strategies. The latter is often a social/political problem that must be well‐informed by the science.
37  Production, survival and morphology of kelp (protista) “sporophytes” arising from selfings, apogamy and hybridizations
Authors: Druehl L. , Collens J.
Published: January 2004

The production and survival of sporophyte morphologies that arose from selfings, parthenogenesis, male apogamy and reciprocal hybridizations of Costaria costata (C.A. Agardh) Saunders, Laminaria saccharina (L) Lamouroux, Alaria marginata Postels and Ruprecht, Eisenia arborea Areschoug, Lessoniopsis littoralis (Tilden) Reinke, Macrocystis integrifolia Bory, and Nereocystis leutkeana (Mertens) Postels and Ruprecht was tracked for 215 hybridization trials for 30 weeks. Each trial consisted of selfings for each species, solo cultures of males and females for each species and reciprocal crossings. At the end of 30 weeks, “sporophyte” survival in the 215 cases was 13% for selfings, 10% for parthenogenesis, 6% for apogamy, and 16% for the reciprocal hybridizations. The morphologies of sporophytes resulting from selfings were typical of the selfed species. Parthenosporophytes and reciprocal hybrids usually had the distinctive morphology of the female parent. Male, apogamously derived “sporophytes” often had reduced morphological features. For example, A. marginata male apogamous sporophytes often lacked a midrib. The sporophyte morphologies that arose in the reciprocal crossings are considered to be putative hybrids. Molecular evidence is required to establish their genetic origins.
38  The sysytematics of ochromonas (chrysophyceae)
Authors: Edgar S. M. , Andersen R. A.
Published: January 2004

Ochromonas sensu lato is the largest genus in the Chrysophyceae, containing over 100 names. Ochromonas species are biflagellate, naked, plastid‐bearing single cells, distinguished from loricate, scaled, colonial and colorless genera. Most, if not all, species of Ochromonas are mixotrophic, i.e., they photosynthesize but they also engulf bacteria and other small prey. Preliminary evidence from SSU rRNA sequences show that Ochromonas is a polyphyletic genus. Ochromonas tuberculata is the most distinct from all other Ochromonas species. The other Ochromonas species (examined thus far) are scattered in three clades. For example, O. danica and O. sphaerocystis are sister to Poterioochromonas stipitata and P. malhamensis. Four additional species (identified by light microscopy as O. elegans Doflein, O. globosa Skuja, O. ovalis Dolfein, O. sociabilis Pringheim) have SSU rRNA sequences identical to P. malhamensis. Of these, only O. sociabilis has been transferred to Poterioochromonas. Thus, at least some species may be synonymous with others. Two clades of marine species are also known, one containing coastal species and the other containing open ocean species. A number of genera (some also polyphyletic) are interspersed amongst the Ochromonas species (e.g., Chrysolepidomonas, Chrysonephele, Chrysoxys, Cyclonexis, Dinobryon, Epipyxis, Uroglena, Uroglenopsis). The goal of this research (just beginning) is to establish a monophyletic Ochromonas, probably by assigning some species to other genera (existing or new). One major problem is that the type species, O. triangulata Vysotskii, hasn't been observed in over 100 years, and it is unclear which of several clades of Ochromonas contains the type. Results will be discussed.
39  Phylogeny of aulacoseira (bacillariophyta)
Authors: Edgar S. M. , Theriot E. C.
Published: January 2004

The phylogeny of 67 populations representing 45 species of Aulacoseira is estimated by maximum parsimony methods using a combination of nucleotide sequence data and qualitative and quantitative morphological characteristics of the silica cell wall gathered primarily from original observation by LM and SEM. A new type of character employing continuous quantitative variables describing the ontogenetic‐allometric trajectories of cell wall characteristics over the life cycle (size range) of diatoms is introduced. In addition to the 45 Aulacoseira species, the phylogeny also incorporates one Alveolophora species, and two outgroup species (Melosira varians and Stephanopyxis cf. broschii). Fifteen species, represented by 24 populations, also contain molecular data from the chloroplast genome (rbcL) as well as the nuclear genome (18S), which were sequenced or downloaded from GenBank. The phylogeny of Aulacoseira is composed of five major clades: 1) an A. crenulata and A. italica clade, which is the most basal, 2) an A. subarctica and A. distans clade, 3) an A. granulata complex clade, 4) an A. ambigua clade, and 5) an A. islandica, A. skvorzowii, A. baicalensis, clade that also contains Alveolophora and many extinct Aulacoseira taxa. Monophyly of Aulacoseira is only achieved if Alveolophora, originally identified as Aulacoseira, is no longer given separate generic status.