Diatoms of North America
Mark Edlund
Taxon Contributor Review Board
Content Editor, Centric Diatoms Diatoms of North America, Editoral Review Board
Senior Scientist Science Museum of Minnesota
It doesn't have to be easy, it just has to be right - EFS
My research interests have developed around algae, especially the diatoms. Diatoms are microscopic algae characterized by their ornate cell walls made of biologically produced glass. I use diatoms to pursue these research areas:
Because diatoms are made of glass, they accumulate in the bottom of lakes, providing researchers clues to conditions in a lake system in earlier times. Our current research is directed at lakes and National Parks across the Upper Midwest. We use diatoms to determine historical lake response, productivity, and nutrient levels to landuse changes, damming, and management practices. My earlier paleolimnological research was used to develop nutrient criteria for Minnesota lakes, to drive policy that reduces loadings to the St. Croix River, and to investigate historical climate change on Devils Lake, ND, and Russia's ancient Lake Baikal.
We are currently surveying the diatom flora of western Mongolia's Valley of the Great Lakes. This landscape is dominated by two large saline lakes (Uvs and Khyargus Nuur) and many smaller lakes that range from fresh to hypersaline. I continue to study diatom biodiversity in an ancient lake system in north-central Mongolia. Lake Hövsgöl is estimated at approximately 1.5 million years old (in comparison to Minnesota's young lakes, which are rarely over 10,000 years old). These projects are in conjunction with researchers at the National University of Mongolia, the Mongolian Academy of Sciences, the University of Minnesota, the Royal Belgian Institute of Natural Sciences, and the Academy of Natural Sciences of Philadelphia.
Conservative estimates set the number of living diatom species at about 25,000, but knowledge of sexuality and life histories is known for only approximately 200 species. This shortfall provides a modern challenge to further a rich scientific history on algal sexuality. My work in this field has centered on description and cytology of sexuality and dormancy strategies.
Projects
Species contributed
Acanthoceras zachariasii | Amphora calumetica | Anomoeoneis fogedii | Anomoeoneis sphaerophora | Asterionella ralfsii var. americana | Aulacoseira islandica | Aulacoseira italica | Biremis undulata | Chaetoceros muelleri | Craticula coloradensis | Cyclostephanos invisitatus | Cyclostephanos tholiformis | Cyclotella quillensis | Diatoma ehrenbergii | Eunotia bidens | Eunotia bilunaris | Eunotia charliereimeri | Eunotia eruca | Eunotia formica | Eunotia metamonodon | Eunotia pectinalis | Eunotia sarraceniae | Eunotia superbidens | Eunotia tauntoniensis | Eunotia zasuminensis | Fragilariforma constricta | Fragilariforma polygonata | Frustulia bahlsii | Gomphonema freesei | Gomphonema gibba | Gomphonema montezumense | Hannaea superiorensis | Hydrosera whampoensis | Lacustriella lacustris | Lindavia bodanica | Lindavia comensis | Lindavia delicatula | Lindavia eriensis | Lindavia michiganiana | Lindavia ocellata | Luticola ignorata | Melosira dickiei | Melosira normannii | Meridion alansmithii | Navicula caterva | Navicula hasta | Neidium sacoense | Orthoseira roeseana | Oxyneis binalis | Oxyneis binalis var. elliptica | Pinnularia turfosiphila | Placoneis amphibola | Placoneis anglophila | Placoneis explanata | Pulchellophycus schwabei | Sellaphora auldreekie | Sellaphora fusticulus | Sellaphora laevissima | Sellaphora moesta | Semiorbis catillifera | Semiorbis eliasiae | Semiorbis hemicyclus | Semiorbis rotundus | Stauroneis bovbjergii | Stauroneis kingstonii | Staurosirella berolinensis | Stephanodiscus binderanus | Stephanodiscus hantzschii | Stephanodiscus hantzschii f. tenuis | Stephanodiscus medius | Stephanodiscus minutulus | Stephanodiscus parvus | Thalassiosira baltica | Ulnaria acus | Ulnaria delicatissima
Species reviewed
Actinocyclus normanii | Aneumastus minor | Aneumastus rostratus | Aneumastus tusculus | Aulacoseira ambigua | Aulacoseira crassipunctata | Aulacoseira granulata | Aulacoseira granulata var. angustissima | Aulacoseira herzogii | Aulacoseira humilis | Aulacoseira newjerseyana | Aulacoseira subarctica | Chaetoceros lauderi | Cyclostephanos dubius | Cyclotella atomus | Cymbellonitzschia diluviana | Cymbopleura stauroneiformis | Decussata placenta | Denticula tenuis | Diadesmis confervacea | Diatomella balfouriana | Diploneis krammeri | Diploneis ovalis | Discostella pseudostelligera | Encyonema latum | Encyonema leibleinii | Encyonema nicafei | Encyonema pergracile | Encyonema reimeri | Encyonema temperei | Encyonema yellowstonianum | Encyonopsis aequaliformis | Encyonopsis albertana | Encyonopsis alpina | Encyonopsis anacondae | Encyonopsis bobmarshallensis | Encyonopsis czarneckii | Encyonopsis dakotae | Encyonopsis descripta | Encyonopsis descriptiformis | Encyonopsis hustedtii | Encyonopsis krammeri | Encyonopsis kutenaiorum | Encyonopsis lacusalpini | Encyonopsis medicinalis | Encyonopsis minuta | Encyonopsis perborealis | Encyonopsis robusta | Eucocconeis alpestris | Eucocconeis flexella | Eucocconeis laevis | Fragilaria recapitellata | Fragilaria vaucheriae | Fragilariforma marylandica | Gomphonema manubrium | Gomphonema sarcophagus | Gyrosigma acuminatum | Krasskella kriegeriana | Kurtkrammeria aequalis | Lindavia affinis | Lindavia rossii | Navicula aitchelbee | Navicula caroliniae | Navicula gregaria | Navicula kotschyi | Navicula metareichardtiana | Navicula piercei | Navicula salinarum | Navicula schweigeri | Navicula staffordiae | Navicula subrhynchocephala | Neidium hitchcockii | Pleurosigma delicatulum | Psammothidium obliquum | Reimeria uniseriata | Stauroneis gracilis | Stauroneis heinii | Stauroneis kishinena | Stauroneis lauenburgiana | Stauroneis pax | Stauroneis phoenicenteron | Stauroneis pikuni | Stauroneis rex | Stauroneis smithii var. incisa | Stauroneis subborealis | Stauroneis supergracilis | Stephanodiscus niagarae | Stephanodiscus reimeri | Stephanodiscus yellowstonensis | Surirella striatula | Surirella tenera | Tetracyclus glans | Tryblionella gracilis
Genera contributed
Acanthoceras | Achnanthes | Achnanthidium | Actinella | Actinocyclus | Adlafia | Afrocymbella | Amphicampa | Amphipleura | Amphorotia | Aneumastus | Anomoeoneis | Asterionella | Aulacoseira | Bacillaria | Biremis | Brachysira | Brevisira | Caloneis | Campylodiscus | Capartogramma | Cavinula | Chaetoceros | Chamaepinnularia | Cocconeis | Cosmioneis | Craticula | Ctenophora | Cyclostephanos | Cyclotella | Cylindrotheca | Cymatopleura | Cymbella | Cymbellonitzschia | Cymbopleura | Decussata | Delicatophycus | Denticula | Diadesmis | Diatoma | Diatomella | Didymosphenia | Discostella | Distrionella | Ellerbeckia | Encyonema | Eolimna | Eucocconeis | Fallacia | Fistulifera | Fragilaria | Fragilariforma | Frustulia | Geissleria | Gomphoneis | Gomphonema | Gyrosigma | Hannaea | Hippodonta | Hydrosera | Hygropetra | Karayevia | Kobayasiella | Lacustriella | Lemnicola | Luticola | Mastogloia | Mayamaea | Melosira | Meridion | Microcostatus | Muelleria | Navicula | Navicymbula | Neidium | Nitzschia | Nupela | Orthoseira | Oxyneis | Pinnularia | Placoneis | Plagiotropis | Planothidium | Platessa | Playaensis | Pleurosigma | Pleurosira | Pliocaenicus | Psammothidium | Pseudostaurosira | Pseudostaurosiropsis | Pulchellophycus | Puncticulata | Reimeria | Rhoicosphenia | Rossithidium | Scoliopleura | Sellaphora | Semiorbis | Skeletonema | Stauroforma | Staurosira | Staurosirella | Stenopterobia | Stephanocyclus | Stephanodiscus | Surirella | Synedra | Tabellaria | Tabularia | Terpsinoë | Tetracyclus | Thalassiosira | Urosolenia