bluuebunny/crossref_metadata_2025 huggingface dataset:
138  Molecular Evolution of Glutamine Synthetase In Protists
Authors: Robertson D. L.
Published: January 2004

Assimilation of nitrogen into structural and functional macromolecules is a critical process in all living organisms. Glutamine synthetase (GS) catalyzes the ATP‐dependent condensation of NH4+ and glutamate thus coupling nitrogen assimilation with carbon metabolism. The GS superfamily is comprised of three gene families: GSI, GSII, and GSIII. Representatives of the three gene families are found in prokaryotes, suggesting the genes are paralogous. In contrast, knowledge of the distribution and evolution of the GS gene families in eukaryotes is limited. The endosymbiotic origin of plastids is well established. Phylogenetic analyses of genes distributed among photosynthetic and non‐photosynthetic organisms may provide insight into the timing and stability of the endosymbiotic events. GSII has been characterized from a variety of prokaryotic and eukaryotic species, including the stramenopiles, Skeletonema costatum and Phytophthora infestans (AAN31463). I evaluated several a priori hypotheses regarding the placement of the stramenopile GSII sequences in addition to performing unconstrained analyses. In all analyses, GSII from S. costatum and P. infestans grouped together. Also, there was strong to moderate support for a ‘protist+plant’ clade, which included the vascular plants, photosynthetic algae, and the non‐photosynthetic P. infestans. Although it remains unresolved whether GSII was transferred from the nucleus of the endosymbiont early in the evolution of stramenopiles, the continued accumulation of GSII sequences from diverse eukaryotes should allow us to rigorously evaluate this hypothesis in the future.
139  Taxonomic Re‐Examination of Eight Species of Nitella (Charales, Charophyceae) from Asia, And Phylogenetic Relationships Within the Genus Based on rbcL and Atpb Gene Sequences
Authors: Sakayama H. , Hara Y. , Nozaki H.
Published: January 2004

Eight taxa of Nitella, collected from Asia, were investigated using LM and SEM of the oospores and sequencing of rbcL gene to improve understanding of their taxonomic status. Our SEM observations demonstrated that the oospore morphology of six taxa –N. capitulifera (=N. acuminata f. capitulifera), N. japonica (=N. furcata f. japonica), N. tumulosa (=N. furcata f. tumulosa), N. megaspora comb. nov. (=N. pseudoflabellata f. megaspora), N. gracillima (=N. gracilis f. gracillima), and N. axilliformis (=N. translucens f. axilliformis) – is distinctly different from that of the species to which R.D. Wood assigned them as infraspecific taxa. Our rbcL sequence data showed that N. japonica is separated phylogenetically from N. furcata, N. tumulosa from N. furcata, N. megaspora from N. pseudoflabellata, and N. axilliformis from N. translucens. In addition, to re‐examine the taxonomic system of Nitella proposed by R.D. Wood, who treated oospore wall ornamentations as a diagnosis at the infraspecific level, we carried out molecular phylogenetic analyses using the combined sequence dataset for atpB and rbcL genes of these eight species, as well as twelve species of Nitella previously studied. The combined sequence data resolved five robust clades within the subgenus Tieffallenia that were characterized by differences in oospore wall ornamentation. However, the species and sectional diagnoses of R.D. Wood, such as the form and cell number of dactyls in vegetative thalli, were variable within the clades. Therefore, R.D. Wood's taxonomic system appears unnatural, at least within the subgenus Tieffallenia.
14  Phylogeny of chlamydomonads isolated from saline habitats: inferences from 18s and 26s rDNA data
Authors: Buchheim J. A. , Kirkwood A. , Henley W. , Buchheim M. A.
Published: January 2004

Although the vast majority of chlamydomonadalean organisms are found in freshwater habitats, several prominent lineages (e.g., Dunaliella, Brachiomonas and some species of Chlamydomonas) are found in brackish, marine or brine environments. Unknown chlamydomonads from Salt Plains National Wildlife Refuge (SPMO; OK USA) and from the Culture Collection of Marine Phytoplankton (CCMP; Bigelow Labs, ME USA) were included in a broad phylogenetic analysis using both 18S and 26S rDNA data. Results indicate that several halotolerant/halophilic lineages can be identified among the Chlamydomonadales. One lineage, which includes Chlamydomonas parkeae, Chl. hedleyi (symbiont of foraminifer) and five CCMP isolates, is allied in the Tetracystis clade with Chl. moewusii and Chl. noctigama. A second group, which includes Chl. reginae, Chl. uva‐maris and CCMP 233, is allied with Chl. monadina. Brachiomonas, which is sister to Haematococcus lacustris, has no close halotolerant/halophilic allies. The three SPMO isolates plus CCMP 220 and CCMP 1641 are resolved as close allies of various Dunaliella taxa. Two of the SPMO isolates are distinctive from a typical Dunaliella cell in that they regularly form non‐flagellated cellular aggregations in normal saline media. In summary, these observations collectively suggest that the ability to live in a saline habitat has arisen, independently, in at least four chlamydomonadalean lineages. In addition, substantial taxonomic revision is required to accommodate virtually all of the unidentified isolates included in this investigation. Supported by NSF DEB 9726588, DEB 0129030, MCB 0132083 and MCB 0132097.
140  Ecophysiology of The Red Alga Porphyra Umbilicalis Kützing (Rhodophyta, Bangalies): Responses to Abiotic Stress
Authors: Sampath‐Wiley P. , Neefus C. D. , Jahnke L. S.
Published: January 2004

The effects of tidal elevation, emersion, sun exposure, and season on several antioxidant enzymes (ascorbate peroxidase, glutathione reductase, and catalase), pigments (phycoerythrin, phycocyanin, chlorophyll a and total carotene) and photosynthetic efficiency of photosystem II (Fv/Fm) in Porphyra umbilicalis were evaluated. Plants were collected monthly from sun‐exposed and shaded locations in the high, mid, and low intertidal following periods of tidal emersion ranging from 0–6 hours. Glutathione reductase activity was greatly affected by emersion during summer months, while ascorbate peroxidase and catalase activities showed no seasonal patterns. Differences in glutathione reductase and catalase levels occurred between sun‐exposed and shaded plants in the high and mid intertidal during summer. At all elevations, photosynthetic pigments showed a strong seasonal trend, with the effect of sun exposure being most apparent during summer. While total carotene increased with emersion during summer months, the combined effects of emersion and season were inconsistent for phycoerythrin, phycocyanin and chl a. Photosynthetic efficiency (Fv/Fm) decreased following emersion in summer and fall. During most months, sun exposed plants had lower Fv/Fm values compared to plants growing in the shade. This study emphasizes the importance of examining the effects of abiotic stresses simultaneously in order to reveal interactive relationships.
141  New Entities in the Order Chaetopeltidales
Authors: Sanchez Puerta M. V. , Leonardi P. I. , Cceres E. J. , O'Kelly C. J.
Published: January 2004

Two species of microfilamentous green algae are added to the Chaetopeltidales, one of which is new to science. The new taxon, to be placed in a new genus and species, is described from a freshwater environment in Argentina, and is placed in the Chaetopeltidales on the basis of its ultrastructural features. Thalli are prostrate, composed of radiating branched filaments that coalesce to form a disc. The pyrenoid is circled by starch plates and traversed by one or two convoluted cytoplasmic channels. The cell walls lack plasmodesmata. Asexual reproduction takes place by means of quadriflagellate zoospores released from central cells of the thallus. The absolute configuration of the zoospore flagellar apparatus is essentially identical to those of other chaetopeltidalean algae. Leptosiropsis torulosa Jao, 1937, isolated from New Zealand freshwaters, is placed in the Chaetopeltidales on the basis of its position in DNA sequence analyses. Thalli consist of erect branched filaments, the cells of which are connected by cross walls without plasmodesmata. The single large pyrenoid surrounds the nucleus. These are the first truly filamentous green algae to be included within the Chaetopeltidales.
142  Insight Into the Mitochondrial Genome of Emiliania Huxleyi (Haptophyta)
Authors: Sánchez‐Puerta M. V. , Bachvaroff T. , Delwiche C. F.
Published: January 2004

Emiliania huxleyi (Lohmann) Hay et Mohler 1967 (CCMP373) is the most abundant representative of the Haptophyta, and can be found in oceanic and neritic waters from subpolar to tropical latitudes. Blooms of this coccolithophorid may reach cell densities of 2.106 ml−1 and emit vast amounts of DMS (dimethyl sulfide), with the potential to affect the global climate. We report here the DNA sequence of more than 21 kb of the mitochondrial genome of this species, out of an approximate total of 30 kb. Preliminary annotation of the genome using database searches identified at least 16 genes. The data were also compared to the unpublished mitochondrial genome of Pavlova lutheri, another member of the haptophytes, and some important differences were identified. Although the gene content of E. huxleyi mtDNA seems to closely resemble that of P. lutheri mtDNA, the gene order differs substantially. Access to the P. lutheri and E. huxleyi mitochondrial genomes will permit the comparative analysis of two deeply diverging members of an ancient and ecologically significant lineage. Among other potential applications, the data will help to clarify phylogeny within the haptophytes as well as to determine the phylogenetic position of this division in relation to other groups of algae, such as heterokonts, dinoflagellates and cryptophytes.
143  Coalescense During Early Recruitment of Mazzaella Laminarioides
Authors: Santelices B. , Hormazábal M. , Aedo D. , Otaíza R.
Published: January 2004

Coalescence in seaweeds is known to occur in the laboratory among young and older sporelings and in the field between neighboring conspecific clumps. However, because spores and germlings are difficult to study in the field, it is as yet unknown at which stage of population development coalescence is most important. Since many seaweeds disperse aggregated propagules, often with a sticky mucilagous envelope around the spores, aggregated recruitment and coalescence might be more important at early stages of population establishment than among fully grown, well established clumps. Using recruitment plates maintained during several experimental times in the field, we are evaluating the above idea with mid‐intertidal populations of Mazzaella laminarioides. During high fertility seasons, close to 45% of the spores settling within or at close (<1 m) distances of the bed exhibited aggregated recruitment, forming groups of 2 to 150+spores. The probability of aggregated recruitments is a function of dispersal distance and spore density. The number of sporelings produced is a function of spore density and coalescence. Highest after‐recruitment mortality (first 15 days) occurs among solitary recruits, followed by sporelings conformed by small number of spores (2–4). Approximately 50% of the spores recruited, isolated or in group, coalesce within these 15 days, gradually forming massive sporelings with increasingly larger basal areas. Thus, after recruitment, sporelings may disappear (die), survive or coalesce. These three alternatives are integrated in a new demographic model for coalescing seaweeds (supported by grant FONDECYT 1020855).
144  Use of Fourier Transform Infrared (FT IR) Diffuse Reflectance Spectroscopy and Hamming Distances to Study the Phycocolloid Chemosystematics of the Red Algae (Rhodophta)
Authors: Sawhney M. , Chopin T.
Published: January 2004

The use of red algal polysaccharide cell wall structures as taxonomic indicators has been a recurring theme in the literature for over 58 years. Traditionally the polymeric phycocolloids of the red algal cell walls have been classified into definite structures (carrageenans and agars) based on the phycocolloids present. However, this method has some obvious shortcomings, such as its inability to assign hybrid structures (carragars), or the appearance of agarocolloids in traditional ‘carrageenophytes’. Thus, there is a need to develop an unbiased method of examining phycocolloid structures without assigning them names. Fourier transform infrared diffuse reflectance spectroscopy was used to analyze the spectra of a large number of red algal species, belonging to several orders. The spectra for each species resulted in a series of ‘peaks’ corresponding to certain wavenumbers (cm−1), which in term correspond to phycocolloid bonds. On the basis of shared/similar peaks, irrespective of their combinations to describe polymeric units, a series of matrices were developed for each family. These were coded as a 0 and 1, indicating the presence or absence of a peak, respectively. Using the concept of vector addition and Hamming distances, a methodology was formulated for analyzing ordinal and familial level groupings. Initial analysis on 173 species, representing 39 families and 12 orders of the Rhodophyta, proved to be promising. Some results corroborated previous studies, while others proved to be informative and raised the need for further chemosystematic studies. This provides the impetus for continuing to develop this method as a contribution to red algal systematics.
145  Preliminary Results of Cytoskeletal Components in Various Red Algae Using Confocal Laser Scanning Microscopy
Authors: Schmidt W. E. , Krayesky D. , Brown R. C. , Lemmon B. E. , Fredericq S.
Published: January 2004

Data concerning the cytoskeletal components of red algae are scant. The goal of this ongoing comparative survey is to develop a more complete characterization of the red algal cytoskeleton, and subsequent elucidation of its function, using representative taxa belonging to major evolutionary lineages within the Rhodophyta. Preliminary data were obtained using enzyme digestion of cell walls and detergent rinses with direct (phalloidin) and indirect (monoclonal antibodies) labeling methods for microfilaments and tubulin, respectively. Samples were viewed using confocal laser scanning microscopy. Results will be discussed in light of the more thoroughly understood cytoskeletal system reported for green algae.
146  Methodological Problems of Marine Macroalgae Age Estimation
Authors: Selivanova O. N.
Published: January 2004

To know the birthdate of any organism is the best way to estimate its age. Unfortunately direct chronometric method, being the most reliable, can't be generally applied. In these cases indirect methods are used. One of them – morphobiometric – is used to estimate age of trees by the number of year rings in the stem or fucoid algae by the number of dichotomic branching. Both methods are widely used however the data obtained may deviate considerably from the true age of the plants. In this study I compared chronometric data on algal age to those obtained by calculation of the number of dichotomic branching in Fucus evenescens growing in Kamchatka, Russia. Field experiments were carried out from 1999 to 2002. No marked with plastic lables plants survived for 3 years. The comparison showed that morphobiometric data exceeded true age of algae at least in 2–3, sometimes even in 5 times. The first year plants can produce up to 5 dichotomous branching per season and can become fertile in the first months of their life. There is information in Russian literature that Kamchatka's F. evenescens age can reach 12–15 years. I consider these data erroneous and suppose underestimation of the number of branches in the early stages of Fucus development to be the cause of overestimation of its true age. In my opinion it is not more than 4–5 years. Application of morphobiometric method is more problematic in case of polytomy. Besides that this method usually causes damage or death of the plant. So I consider that only chronometric method can give the researcher exact information on the age of macroalgae.
147  Controlling Harmful Algal Blooms Through Clay Flocculation
Authors: Sengco M. R. , Anderson D. M.
Published: January 2004

The potential use of clays to control harmful algal blooms (HABs) has been explored in East Asia, Australia, the United States, and Sweden. In Japan and South Korea, minerals such as montmorillonite, kaolinite, and yellow loess, have already been used in the field effectively, to protect fish mariculture from Cochlodinium spp. and other blooms. Cell removal occurs through the flocculation of algal and mineral particles, leading to the formation of larger aggregates (i.e. marine snow), which rapidly settle and further entrain cells during their descent. In the U.S., several clays and clay‐rich sediments have shown high removal abilities (e.g. >80% cell removal efficiency) against Karenia brevis, Heterosigma akashiwo, Pfiesteria piscicida and Aureococcus anophagefferens. In some cases, the removal ability of certain clays was further enhanced with chemical flocculants, such as polyaluminum chloride (PAC), to increase their adhesiveness. However, cell removal was also affected by bloom concentration, salinity, and mixing. Cell mortality was observed after clay addition, and increased with increasing clay concentration, and prolonged exposure to clays in the settled layer. Mesocosm, field enclosure, and flume experiments were also conducted to address cell removal with increasing scale and flow, water‐column impacts, and the possible benthic effects from clay addition. Results from these studies will be presented, especially those in regards to water quality, seawater chemistry, bottom erodibility and faunal impacts in the benthos. At this time, clay dispersal continues to be a promising method for controlling HABs and mitigating their impacts based on existing information and experimental data.
148  Life History and Feeding Preferences of Gallery‐Forming Harpacticoids in Dictyotalean Seaweeds
Authors: Shimono T. , Sasaki H. , Kawai H.
Published: January 2004

The harpacticoid copepod Dactylopusioides macrolabris has been reported to make galleries beneath the cuticle of cortical cells of Dictyota dichotoma (Dictyotales, Phaeophyceae; Green 1958). Besides this species, we have found several more harpacticoids from Japanese coasts that have similar habits, infesting various dictyotalean species. In laboratory culture experiments growing the harpacticoids for several generations and recording their behaviors by interval video recoding, we have found that these harpacticoids spend most of the lives in the galleries, feeding only on the algal tissues. Different species showed different feeding preferences even among morphologically very close species: one species fed most of the dictyotalean species examined, whereas another species could digest only one species. In order to discuss the evolutionary interactions between the harpacticoids and host seaweeds, comparative molecular phylogenetic analyses of the harpacticoids and host seaweeds were studied using rDNA ITS2 (harpacticoids) and rbcL (Dictyotales) DNA sequences.
149  Distribution and Invasion of Bangia Atropurpurea (Rhodophyta) in the Laurentian Great Lakes
Authors: Shea T. B. , Vis M. L. , Sheath R. G. , Müller K. M.
Published: January 2004

Müller et al. (1998) noted that freshwater collections of the genus Bangia formed a distinct group separate from marine entities in gene sequence analyses. Recently, the species epithet B. atropurpurea has been resurrected to represent this freshwater lineage. This taxon is one of many invasive species within the Laurentian Great Lakes. B. atropurpurea was first observed in Lake Erie in 1964 and by 1982 was observed in all of the Great lakes except Lake Superior. The present study was initiated to examine the further spread of B. atropurpurea and determine the origin of these populations. Hence, a survey of all the Great Lakes was conducted in 1995 (86 sites) and again in 2002 (104 sites). Bangia was observed at 43 sites in 1995 and 39 sites in 2002. For the first time, this alga has been observed to be present in the St. Lawrence River (1995), Georgian Bay on Lake Huron (2002) and Lake Simcoe (eastern shore, 2002) and hence this alga appears to be spreading into new locations. Cluster analyses of morphological data reveal three distinct groupings that do not separate according to location or lake basin. Preliminary analyses of ITS 1 and 2 sequences show differences among samples within Lake Ontario and among all Lakes; however, collections from Lake Simcoe are very similar in sequence. We are continuing to examine the relationship of Great Lakes populations with freshwater collections from Europe.
15  Phylogeny of the chlorophyta: inferences from 18S and 26S rDNA
Authors: Buchheim M. A. , Buchheim J. A.
Published: January 2004

Recent studies of the Chlorophyceae using 18S and 26S rDNA data in meta‐analysis have demonstrated the power of combining these two sets of rDNA data. Furthermore, the 26S rDNA data complement the more conserved 18S gene for many chlorophycean lineages. Consequently, this data approach was pursued in an expanded taxon‐sampling scheme for the Chlorophyta, with special reference to the classes Chlorophyceae and Trebouxiophyceae. Results of these new phylogenetic analyses identify Microspora sp. (UTEX LB 472) and Radiofilum transversale (UTEX LB 1252) as sister taxa which, in turn, form a basal clade in the Cylindrocapsa alliance (Treubaria, Trochiscia, Elakatothrix). The relative position of the “Cylindrocapsa” clade within the Chlorophyceae remains uncertain. The enhanced taxon‐sampling has not resolved the relative positions of the Oedogoniales, Chaetophorales or Chaetopeltidales. Furthermore, the Sphaeropleaceae are supported as members of the Sphaeropleales in only some analyses, raising concerns about the status of the order. Although based on a limited set of taxa (currently <10), a combined data approach reveals support for a monophyletic Trebouxiophyceae that includes the distinctive organisms, Geminella and Eremosphaera. The goal of a well‐resolved phylogeny for the Chlorophyta remains just that, a goal. Achieving that goal obviously will require additional taxon sampling in the Prasinophyceae and Ulvophyceae, as well as, the Trebouxiophyceae. Moreover, it is clear that other genes (e.g., cp‐atpB, cp‐rbcL, cp‐16S, mt‐nad5) will be needed to help address problems of resolution based on the rDNA data alone. Supported by NSF DEB 9726588 and DEB 0129030.
150  Phylogenetic Systematics and Phenology of the Hawaiian Endemic Freshwater Red Alga, Batrachospermum Spermatiophorum
Authors: Sherwood A. R. , Vis M. L. , Sheath R. G.
Published: January 2004

The only known population of Batrachospermum spermatiophorum Vis et Sheath, located in a small stream on east Maui, Hawaii, was sampled from November 2001 to October 2002 to investigate its phenology and taxonomy. Phylogenetic analyses of the rbcL gene for B. spermatiophorum confirm its placement within the Section Contorta. Comparison with rbcL gene sequences for all other available Batrachospermum species illustrates that B. spermatiophorum is distinct in its rbcL nucleotide sequence and should be maintained as a separate species. The phenology of B. spermatiophorum differed from similar studies on temperate Batrachospermum species in that gametophytes were present year round, and no “chantransia” stages were identified at any point during the study. Maximum plant length was highest in late fall and early winter months, while gametangial production peaked in February and March. Carposporophyte abundance rose sharply in July and August, and the percent of carposporophytes producing carpospores was highest in late summer and early fall months. The year‐round presence of gametophytes may be a result of fewer seasonal cues in the tropical environment than occur in temperate locations.
151  Phylogenetic Analysis of The Subgenus Euglena with Particualr Reference to the Type Species Euglena Viridis (Euglenophyceae)
Authors: Shin W. , Triemer R. E.
Published: January 2004

Euglena viridis was first described by Antony van Leeuwenhoek in 1674. This taxon later became the type for the genus Euglena erected by Ehrenberg in 1838. The primary characters that distinguish this taxon are the single stellate chloroplast and spherical mucocysts. A number of related Euglena species are similar in size, bear one or two stellate plastids and possess spherical or spindle‐shaped mucocysts. We conducted morphological and molecular studies on taxa in the subgenus Euglena (all of which bear stellate chloroplasts) and compared this to genera in the subgenus Calliglena (non‐stellate chloroplasts). Morphologically the strains in subgenus Euglena were very similar, except for chloroplast number and mucocyst shape. The E. stellata group has one chloroplast and a distinctive spindle‐shaped mucocyst; the E. geniculata group has two chloroplasts and spherical mucocysts; the E. viridis group has one chloroplast and spherical mucocysts. Molecular analyses using SSU and LSU rDNA demonstrated that the subgenus Euglena is not monophyletic. The combined SSU/LSU trees provide strong support for a stellate clade (subgenus Euglena), but one strain of E. viridis diverges at the base of the Euglena/Calliglena lineage. Multiple subclades are found within the main stellate clade. E. tristellata forms a separate divergence and four E. stellata strains form a single, well‐supported subclade. Two E. viridis strains are among the E. geniculata group clade, while six others form two separate, but well‐supported clades. This study demonstrates that the type species, E. viridis, is paraphyletic and will need to be redefined.
152  Non‐Indigenous and Invasive Marine Algae in Hawaii
Authors: Smith C. M. , Smith J. E. , Hunter C. L.
Published: January 2004

Histories, patterns of introduction, management of impacts and predictable futures? Ecological impacts of weedy introduced and native marine algae have set Hawai'i apart from elsewhere in the tropics and offers a new show case for macroalgal blooms. Partly because of our isolation, impacts of non‐indigenous species have been clearly identified, in some cases almost as quickly as introductions have occurred to Hawai'i. While hull fouling or intentional introductions may have been initial mechanisms for macroalgal introductions, spread among the Hawaiian Islands is not necessarily linked to the vector for arrival. Further, impacts of non‐indigenous species are also not fully predictable, prior to introduction. This situation leads to challenging gaps in management strategies because few generalizations about the roles of nutrients or herbivory as drivers for macroalgal blooms can be supported at this time. Weedy native species represent a wide range of alternate impacts with other apparent combinations of forcing functions. Case histories for the most significant non‐indigenous and weedy native algae will be presented with emphasis on potential new criteria to assess ecological impacts and provide resource biologists with critical new tools for the management of reef ecosystems.
153  Invasive Macroalgae on Tropical Reefs: Impacts, Interactions, Mechanisms and Management
Authors: Smith J. E.
Published: January 2004

The introduction of non‐indigenous species is currently viewed as one of the largest threats to global biodiversity. Non‐indigenous marine algae (NIMA) in temperate seas around the world have caused significant losses to ecosystem structure and function. However, the introduction of invasive species in tropical marine ecosystems has not typically been viewed as a significant threat despite the number of species that have been transported to reef regions around the world for open‐reef aquaculture. The research presented here represents some of the first quantified evidence of significant negative impacts of NIMA in tropical waters. This study characterized several ecological and physiological aspects of one the most successful and potentially threatening NIMA on Hawaii's coral reefs, K. alvarezii. Results of large‐scale surveys and a number of permanently established invader removal plots suggest that K. alvarezii is having negative impacts on native species diversity. Interactions between K. alvarezii and coral abundance were examined using photoquadrats and results indicate that the invader is causing coral death as a result of overgrowth and shading. Possible mechanisms influencing invader success including responses to nutrient enrichment, grazer consumption rates and reproductive characteristics were examined. Results from a number of experiments suggest that without mitigation K. alvarezii will continue to spread. In an effort to minimize negative impacts and prevent spread several management strategies were examined including manual removal, use of chemical and temperature treatments and enhancement of native sea urchins. While some of these tools are promising control options, rapid implementation is needed to prevent further damage.
154  Developments on Two Newly Cultivated Species Capsosiphon Fulvescens and Costaria Costata in Korea
Authors: Sohn C. H.
Published: January 2004

In the recent years, there has been increasing demand of nutritive and health foods in Korea. Species diversification is needed in order for seaweed aquaculture to take advantage of these expanding markets. With this in mind, the cultivation of Capsosiphon fulvescens and Costaria costata, was successfully developed. Capsosiphon fulvescens is a filamentous chlorophycean alga growing in the upper littoral regions of the rocky‐shore. It has been used as food in the form of soup with oysters along the Southwestern Coast of Korea. After the development of artificial ¡ seed¡± production (control of light, photoperiod and temperature of parthogenetic gametes), pilot scale, and then large scale, cultivation techniques were established for mass culture of this species. In 2001, the retail price was about $6.2/kg fresh wt with a total production of 770 ton. Costaria costata, a phaeophycean alga, was initially cultivated along the Eastern Coast of Korea. It has now been transplanted successfully to culture grounds along the Southern Coast. The cultivation techniques are very similar to Undaria and Laminaria, ie. long line techniques. It¡¯price is about $1.7/kg fresh wt with total production of 2,000 ton. An overview of these new maricultures technologies that have lead to the successful expansion of the seaweed industry in Korea will be presented.
155  Mapping Floating Kelp Beds in Alaska With Remote Sensing
Authors: Stekoll M. S. , Deysher L.
Published: January 2004

The commercial harvest of floating kelps has promise as a business opportunity that could be especially valuable for small communities in southeast Alaska. The giant kelp, Macrocystis, is harvested mainly for the commercial herring roe‐on‐kelp harvest in Alaska. In addition, in southeast Alaska the two other species of floating kelps, Nereocystis luetkeana and Alaria fistulosa, have been commercially harvested since 1992 for use as agrochemicals by the Alaska KelpCo. The continued existence of this company and others that may wish to harvest seaweeds on a commercial basis is threatened by the lack of a kelp harvest management system in Alaska. The objective of this research is to develop a reliable and cost effective method for estimating the aerial extent and the standing crop biomass of the floating kelps in SE Alaska. We are employing an aerial multispectral imaging system that can be flown at varying altitudes to achieve spatial resolutions ranging from 0.5 to 2 meters. We are investigating whether the three species have unique spectral or textural characteristics in the multispectral imagery that can be used to differentiate the populations. The end products for this project will be kelp resource maps that delineate the spatial extent and biomass of kelp populations within the beds and a methodology for assessing kelp beds with mixed species composition. These products will find use by resource managers such as the Alaska Department of Fish and Game and the Department of Natural Resources.
156  Effects of Light and Nutrients on Periphyton Community Composition in a Hawaiian Stream
Authors: Stephens S. H. , Smith C. M.
Published: January 2004

Streams in Hawaii are experiencing increasing anthropogenic impacts due to agriculture and urbanization via nutrient enrichment and riparian canopy removal. The effects of these factors on stream algal communities in Hawaii have rarely been studied using manipulative experiments. A study was conducted in a slightly impacted forested stream on Oahu, Hawaii, to examine the effects of nutrient enrichment and canopy cover on the benthic algal community, especially diatoms. Benthic algae were colonized onto nutrient‐diffusing substrata in a factorial design with nitrate and phosphate enrichments, at high and low light levels at similar elevations. Algal productivity as measured by ash‐free dry mass and chlorophyll a levels increased significantly with nitrate enrichment at the high light site. Pulse‐amplitude modulated (PAM) fluorescence was used to estimate photosynthetic parameters in situ, and indicated a higher maximum photosynthetic rate for the algal community with nitrate enrichment at the high light site. Significant differences in diatom community composition were observed at low and high light sites, and several diatom species also responded significantly to either nitrate or phosphate enrichment at both sites. These results suggest that benthic stream algal communities in Hawaii may be significantly affected by human activities within watersheds.
157  Examining Phytoplankton Communities with Environmental PCR
Authors: Stiller J. W.
Published: January 2004

Recent advances in biotechnology have taken much of the guesswork out of many molecular biological procedures, and promote a high rate of success even for relative beginners. In designing the laboratory component of my Phycology course, I have taken advantage of these improved methods to develop a semester‐long, molecular‐based class project, using “environmental PCR” to examine phytoplankton diversity. Students learn a number of common molecular techniques within the context of dynamic and unrehearsed phycological research. This provides a greater appreciation of the general utility of molecular technology, and its application to algal systems in particular. A series of easy to follow protocols are linked together, allowing students to PCR amplify sequences from mixed environmental samples, clone the resulting fragments to separate individual sequences, screen the clones by restriction enzyme digests and sequence clones with clearly different restriction patterns. The resulting sequences then are used in BLAST searches of GenBank to determine the nearest available match among sequences annotated previously. The techniques allow both qualitative and quantitative estimates of the organisms present, as well as comparative analyses of the diversity observed through direct visual observations versus those recovered by PCR. Each step of the procedure can be accomplished in the duration of a typical 3 hour lab period, and most involve intervals of incubation that permit adequate time for other lab exercises, such as a survey algal diversity, on which traditional phycological laboratories are based.
158  Algal Turf Composition at Two Coastal Locations on the Island Of Hawai'i
Authors: Stuercke B. , McDermid K. J.
Published: January 2004

Algal turfs, or mats of interwoven multispecific algal 1–3 cm in height, play an important role in the reef community in Hawai'i, and yet they are often overlooked. Two sites on opposite coasts of the island (Richardson's Beach Park and Puako) were sampled from September 2000 to July 2002. The samples from quadrats along transect lines were analyzed to find percent abundance of each species. Specimens were examined microscopically to generate a species list. Over 50 different species of algae were identified, and red algae (Rhodophyta) dominated the samples at both sites. Several new records for the island of Hawai'i were found. Algal turf species diversity (H') varied between sites and among sampling dates. The most abundant species showed aggregated or patchy spatial patterns in the turf.
159  Incertae Sedis No More: The Phylogenetic Affinity of Helicosporidia
Authors: Tartar A. , Boucias D. G.
Published: January 2004

The Helicosporidia are a unique group of pathogens found in diverse invertebrate hosts. They have been considered to be either protozoa or fungi, but have remained incertae sedis since 1931. Following the isolation of a Helicosporidium sp. in Florida, we showed that the Helicosporidia are non‐photosynthetic green algae. Phylogeny reconstruction inferred on several housekeeping genes (including actin and b‐tubulin) consistently and stably grouped Helicosporidium sp. among member of Chlorophyta. Additionally, nuclear SSU rDNA phylogenies identified Helicosporidium as a sister taxa to another parasitic, non‐photosynthetic algal genus: Prototheca (Chlorophyta, Trebouxiophyceae). Comparison of mitochondrial (cox3) and chloroplast (rrn16) genes confirmed that Helicosporidium and Prototheca have arisen from a common photosynthetic ancestor, and suggested that Helicosporidia contain Prototheca‐like organelles, including a vestigial chloroplast (plastid). In an effort to better characterize the biology of Helicosporidium sp., a cDNA library has been constructed and expressed sequences tags (ESTs) have been generated. Most of these ESTs exhibited similarity with algal and plant genes. Significantly, the EST library provided with additional evidence that Helicosporidium sp. does have a plastid, as numerous nuclear‐encoded, plastid‐targeted genes were identified. Characterization of the plastid is currently underway: several chloroplast‐like genes (rrn16, rrn23, tufA) have been cloned and their sequences are being used to isolate the entire plastid genome. Similar to the situation described in Prototheca, the Helicosporidium plastid may be reduced, as most of the genes involved in photosynthesis likely have been lost during the course of evolution.
16  Comparisons of macrophyte cover and community primary productivity on two southern california shores
Authors: Bullard A. M. , Murray S. N.
Published: January 2004

Light‐saturated net photosynthetic rates and cover of rocky intertidal macrophytes were determined between January and March 2003 at two southern California sites characterized by different macrophyte standing stocks. Overall macrophyte cover at Little Corona del Mar was low (75.4%) and was dominated by articulated corallines, and small, turf‐forming crustose algae that provide little habitat structure. Macrophyte cover was higher at Dana Point (99.4%), where larger, frondose seaweeds were more abundant (34% vs < 5% cover). Our light‐saturated photosynthetic rates for Little Corona del Mar and Dana Point macrophytes were similar to values for the same species obtained during the 1970s and 1980s. Highest photosynthetic rates were obtained for thinner, sheet‐like, and branched, frondose seaweeds, while lowest rates were found for articulated coralline and crustose algae. We estimated the net community productivity of the two sites using photosynthetic rates (calculated as mg C m−2 · h−1) and percent cover data for the most abundant populations. We also compared our community productivity estimates for Little Corona del Mar and Dana Point with values for the same sites calculated using macrophyte cover values obtained during the mid‐1970s. Re‐sampling studies of these and other regional sites reveal that lower‐producing, crustose and coralline algae have become increasingly abundant while the cover of higher‐producing, frondose algae has declined on many southern California shores. Our studies at Little Corona del Mar and Dana Point, indicate that changing macrophyte abundances can have significant effects on the primary productivity of rocky intertidal communities.
160  Copepodology for the Phycologist with Apologies to G. E. Hutchenson
Authors: Tester P. A.
Published: January 2004

Heterocapsa triquetra is one of the most common bloom forming dinoflagellates found in estuaries and near shore regions around the world. In order to bloom, H. triquetra optimizes a suite of factors including low grazing pressure, increased nutrient inputs, alternative nutrient sources, and favorable salinity and hydrodynamic conditions, as well as the negative factors of temperature‐limited growth, short day lengths, and periods of transient light limitation. The prevailing environmental conditions associated its wintertime blooms are largely the result of atmospheric forcing. Low‐pressure systems moved through coastal area at frequent intervals and are accompanied by low air temperatures and rainfall. Runoff following the rainfall events supplies nutrients critical for bloom initiation and development. Heterocapsa triquetra blooms can reach chl a levels >100 mg L−1 and cell densities between 1 to 6×106 L−1. As the blooms develop, nutrient inputs from the river became insufficient to meet growth demand and H. triquetra feeds mixotrophically, reducing competition from co‐occurring phytoplankton. Cloud cover associated with the low‐pressure systems light limit H. triquetra growth as do low temperatures. More importantly though, low temperatures limit micro and macrozooplankton populations to such an extent that grazing losses are minimal.
161  The Recent Spread of an Invasive Kelp, Undaria Pinnatifida, in California: How Similar is This Invasion to Other Undaria Invasions Worldwide?
Authors: Thornber C. S.
Published: January 2004

Invasive algal species have the potential to change the structure and ecology of native algal communities. One well‐known invader, the large Japanese kelp Undaria pinnatifida, has recently become established at several locations along the central and southern California coast (Monterey, Santa Barbara, Catalina, and others). Previous to its introduction in the northeastern Pacific, Undaria has become established along the coastlines of several countries, including Australia, New Zealand, Argentina, England, and France. However, the seasonal population dynamics, rate of spread, and impact on local communities at each invasion site varies. Undaria in the Santa Barbara, CA harbor exhibits two distinct recruitment pulses per year (fall, late winter), with nonoverlapping generations of adult individuals. Individuals can grow rapidly and become reproductive a month after appearing as recruits (2–3 cm long), indicating a potential for rapid spread. However, Undaria may be effectively controlled by grazing via natural recruitment of the kelp crab Pugettia producta. However, Undaria invasions in other California invasions have not been controlled by herbivory, and Undaria populations in these areas have the potential to compete with a wide diversity of native California kelp species for habitat space and light.
162  Interactions Between Planktonic Microalgae and Protozoan Grazers
Authors: Tillmann U.
Published: January 2004

For an algal bloom to develop, the growth rate of the bloom‐forming species must exceed the sum of all loss processes. Among these loss processes, grazing is generally believed to be one of the more important factors. Based on numerous field studies it is now recognised that microzooplankton are dominant consumers of phytoplankton in both open ocean and coastal waters. Heterotrophic protists, a major component of microzooplankton communities, constitute a vast complex of diverse feeding strategies and behaviour which allow them access to even the larger phytoplankton species. A number of laboratory studies have shown the capability of different protistan species to feed and grow on bloom forming algal species. Because of short generation times, their ability for fast reaction to short‐term variation in food conditions enables phagotrophic protists to fulfil the function of a heterotrophic buffer, which might balances the flow of matter in case of phytoplankton blooms. The importance of grazing as control of microalgae becomes most apparent by its failure; if community grazing controls initial stages of bloom development, there simply is no bloom. However, if a certain algal species is difficult to graze, e.g. due to specific defence mechanisms, a reduced grazing pressure will certainly favour bloom development. The present contribution will provide a general overview on the interactions between planktonic microalgae and protozoan grazers with special emphasis on species‐specific interactions and algal defence strategies against protozoan grazers.
163  Identification of Euglenoids That Produce Ichthyotoxin(S) (Euglenophyta)
Authors: Triemer R. E. , Zimba P. V. , Rowan M.
Published: January 2004

Diatoms, dinoflagellates, pelagiophytes, prymnesiophytes, and cyanobacteria are the only divisions of microalgae known to produce toxins. We now report toxin production by freshwater members of the genus Euglena. Fish mortalities (sheepshead minnows, catfish, striped bass, and tilapia) have been observed following exposure in the field to Euglena blooms and in the laboratory when exposed to unialgal isolates of two species of Euglena (E. sanguinea Ehrenberg and E. granulata (Klebs) Lemm.). Three toxic fractions have been isolated from unialgal isolates of both species, and include both water soluble and lipophilic compounds having ichthyotoxic activity. The toxins are stable at −80°C for at least 60 days and are heat stable to 30°C. Erratic swimming behavior of fish suggests a neurological toxin. This is the first report of fish kills by any freshwater algal taxa from both field and laboratory studies.
164  Chemical Antiherbivore Defenses of Temperate Green Macroalgae
Authors: Van Alstyne K. L. , Nelson A. V. , Campos A.
Published: January 2004

Many temperate green macroalgae contain secondary meatbolites that provide protection from grazing by some herbivores. These include the production of dopamine hydrochloride by the ulvoid green alga Ulvaria obscura and the production of dimethylsulfoniopropionate (DMSP) by many species of Ulvales and Caulerpales. The dopamine hydrochloride defense was isolated using bioassay‐guided fractionation and is effective against sea urchins (Strongylocentrotus droebachiensis) and littorinid snails (Littorina sitkana). The DMSP activated defense system involves enzymatic cleavage of DMSP into dimethyl sulfide (DMS) and acrylic acid. It is found in many of the Ulvales and several species of Codium in the northeastern Pacific and Australasian regions. Many green algae such as Ulva fenestrata and Enteromorpha linza are avoided by urchins, which are deterred by DMS and acrylic acid in laboratory assays. However, these algae are often preferred foods of snails, which are deterred by DMS and acrylic acid. Snails may preferentially consume ulvoid green algae, despite being deterred by DMS and acrylic acid, because these algae contain relatively high nitrogen concentrations.