Algal Biodiversity Research Articles

The Single, Ancient Origin of Chromist Plastids

AbstractPhylogenetic comparisons suggest that plastid primary endosymbiosis, in which a single‐celled protist engulfs and ‘enslaves’ a cyanobacterium, likely occurred once and resulted in the primordial alga. This photosynthetic cell diversified, through vertical evolution, into the ubiquitous green (Chlorophyta) and red (Rhodophyta) algae, and the more scarce Glaucophyta. However, some modern algal lineages have a more complicated evolutionary history involving a secondary endosymbiotic event, in which a protist engulfed an existing eukaryotic alga (rather than a cyanobacterium), which was then reduced to a secondary plastid. Secondary endosymbiosis explains the majority of algal biodiversity, yet the number and timing of these events is unresolved. Here we analyzed a five‐gene plastid dataset to show that a diverse group of chlorophyll c‐containing protists comprising cryptophyte, haptophyte, and stramenopiles algae (Chromista) share a common plastid that most likely arose from a single, ancient (about 1260 million years ago) secondary endosymbiosis involving a red alga. This finding is consistent with C. monophyly and implicates secondary endosymbiosis as a driving force in early eukaryotic evolution.

Watershed-Scale Comparisons of Algal Biodiversity in High-Quality Proximate Hawaiian Stream Ecosystems

The stream macroalgal floras of two proximate, high-quality stream valleys (Hanakapi'ai and Limahuli) located on the northern quadrant of the Hawaiian island of Kaua'i were inventoried and compared on a watershed scale, providing interesting insight into Hawai'iOs potential taxonomic diversity and the influential role played by physical factors in shaping community characteristics. A total of 26 species of macroalgae (five Cyanophyta, 18 Chlorophyta, one Rhodophyta, and two Chromophyta) was identified, of which only eight were common to both streams. Chlorophyta composed the majority of macroalgal taxa identified (63.2% in Hanakapo'ai Stream and 66.7% in Limahuli Stream). Three macroalgal species are new records for Hawai'i and one (Chamaesiphon curvatus var. elongatum Nordst.) is a Hawaiian endemic. Significant differences in the macroalgal densities between Hanakapo'ai and Limahuli Streams (Chlorophyta versus Chromophyta, respectively) were attributed to measured differences in riparian canopy cover (34.8% versus 70.0% closed, respectively). Significantly lower densities of macroalgal species in riffle-run habitats in Hanakapi'ai as compared with Limahuli Stream were potentially explainable by top-down control by robust populations of native herbivorous fish species.

A DISTRIBUTIONAL ANALYSIS OF BENTHIC MARINE ALGAE COLLECTED IN SOUTH CENTRAL ALASKA DURING THE CHIA STUDIES OF EVOS

Hansen, G. I.1 & Stekoll, M. S.2 1Hatfield Marine Science Center, Oregon State University, Newport, OR 97365 USA; 2Juneau Center for the School of Fisheries and Ocean Sciences, University of Alaska, Juneau, AK 99801 USADuring the University of Alaska's Coastal Habitat Injury Assessment (CHIA) study of the Exxon Valdez oil spill, intensive investigations were carried out on the intertidal algal communities of Prince William Sound, the Kenai Peninsula, the Kodiak Islands, and the Alaska Peninsula. As a part of these investigations, thorough voucher collections were made of the benthic marine algae present in more than 100 transect areas used for the study. The 7,300 collected specimens were pressed, identified to species, curated, and cataloged. For this study, we have utilized these data as well as information on the habitat types and species life histories to prepare regional checklists and distributional analyses of the species discovered. Environmental conditions in south central Alaska vary regionally as well as seasonally, and the narrow vs. broad ranges of these species appear to reflect closely their ability to tolerate these diverse conditions. The algal biodiversity, distribution, and habitat data made available through this study provide crucially needed background information for future environmental impact studies and for restoration and conservation efforts in Alaska.

Biodiversity of aquatic algal communities in the Sikhote-Alin biosphere reserve (Russia): Biodiversité des communautés algales de la réserve de la biosphère Sikhote-Alin (Russie)

This paper presents the results of long-term research regarding the algal biodiversity of the Sikhote-Alin biosphere reserve, Primorsky region (Russian Far East). The algal flora is compised of 675 species represented by 839 subspecific taxa from seven divisions: Cyanophyta, 77 (91 including subspecific taxa); Euglenophyta, 18 (21); Chlorophyta, 84 (86); Streptophyta, 137 (169); Rhodophyta, 3; Ochrophyta, 355 (468): Diatomophyceae, 331 (444), Chrysophyceae, 6, Xanthophyceae, 16, Phaeophyceae, 2; Dinophyta, 1. The algal floras of ecologically different reserve water bodies are described, including the brackish, Blagodatnoe Lake, the shallow freshwater Golubichnoe Lake, the alpine Solontsovskie Lakes, the rapid cold-water Serebryanka and Dzhigitovka rivers, and the lowland Kolumbe River. The taxonomic composition of the algal flora has been analysed. Differences between the algal communities of lakes and rivers are described and rare species are noted. The algal flora of the Sikhote-Alin biosphere reserve is currently the richest and most diverse of the six reserves studied in the Primorsky region.

Marine viruses and their biogeochemical and ecological effects.

Viruses are the most common biological agents in the sea, typically numbering ten billion per litre. They probably infect all organisms, can undergo rapid decay and replenishment, and influence many biogeochemical and ecological processes, including nutrient cycling, system respiration, particle size-distributions and sinking rates, bacterial and algal biodiversity and species distributions, algal bloom control, dimethyl sulphide formation and genetic transfer. Newly developed fluorescence and molecular techniques leave the field poised to make significant advances towards evaluating and quantifying such effects.

A Natural Spore Trap for Algae in Polluted Estuaries

Fucus vesiculosus was transplanted from one locality with an impoverished flora to another with a species-poor but different vegetation. Discs of Fucus thallus incubated in culture showed a significant increase in epiflora in the transplants. The possible applications to routine monitoring of polluted estuaries are discussed.Harmful effects of pollution on the algal biodiversity of estuaries have been reported in numerous floristic studies (e.g. Edwards, 1972). The species-list approach suffers from a number of quite serious flaws: it is highly labour intensive; the absence of sampling rigour makes it difficult to interpret the results; and it is unsuitable as a basis for routine monitoring. In order to overcome these objections, it was decided to see if Fucus vesiculosus L. (Algae: Fucophyceae) a perennial macrophyte with high tolerance to pollution, can function as a trap for spores of smaller algae in the same locality and so express, in some way, the species richness of the surrounding vegetation. The method adopted to test this idea was simply to transfer Fucus from one locality with an impoverished flora to another with a species-poor but different vegetation, and then to quantify the effects of transference on the diversity of the epiflora.

Diversity of eukaryotic algae

Algae are ubiquitous. They are the primary producers for all the oceans and seas, an area that covers 71% of the Earth's surface. Algae also occur in freshwater lakes, ponds and streams as well as on and in soil, rocks, ice, snow, plants and animals. In total, 40% of global photosynthesis is contributed by algae. The algae are tremendously diverse. These are at least seven distinct phylogenetic lineages that arose independently during geological time and that evolved at different rates (based upon molecular clocks). Consequently, the algaein toto do not form a single, cohesive group, and they must be considered a polyphyletic assemblage. The red algal lineage has approximately 5000 recognized species (excluding nomenclatural synonyms, superfluous names, etc.) that are extant, and an estimated 500 to 15 000 new species remain to be described. The green algal lineage has approximately 16 000 recognized extant species and up to 100 000 species that remain to be described. The chromophyte lineage has approximately 15 000 recognized extant species and from one to ten million species that remain to be described. The dinophycean lineage (primarily dinoflagellates) has approximately 3000 recognized, extant species and workers estimate that from 500 to 8000 species remain to be described. The euglenophyte lineage has approximately 900 recognized extant species, and experts estimate that up to 1000 species remain to be described. The cryptophyte lineage is undergoing total revision and the numbers of species is very uncertain; perhaps 200 extant species are recognized and 1000 species remain to be described. The glaucophyte lineage has 13 recognized species, and perhaps several dozen species remain to be described. Since the 1960s, clonal culture followed by electron microscopic examination is often required before an alga can be identified or described as new. Recently, electron microscopy is being augmented by, or replaced by, gene sequence comparisons. Both electron microscopy and molecular sequencing are time consuming and expensive methods that slow the descriptions of new species. Time consuming methods for describing new algal species, a reduction in the number of algal systematists, a reduction in funds to support systematic research, and phycologically unexplored geographical areas act synergistically to hamper the rate of accessing algal biodiversity.