Distribution, phylogeny, and growth of cold-adapted Picoprasinophytes in Arctic Seas

• Published in: Journal of Phycology
• Main Authors: Lovejoy, Connie, Vicent, Warwick F., Bonilla, Sylvia, Roy, Suzanne, Martineau, Marie-Josée, Potvin, Marianne, Massana, Ramon, Pedrós-Alió, Carlos
• Format: Article in Journal/Newspaper
• Language: English
• Published: Phycological Society of America 2007
• Subjects: Arctic Ocean; Biogeography; Climate change; Phytoplankton; Picoeukaryotes; Picoplankton; Pigments; Polar; Prasinophytes; Psychrophiles; Arctic; Canada; Ellesmere Island; Greenland; Arctic Basin; Beaufort Sea
• Online Access: http://hdl.handle.net/10261/26982; https://doi.org/10.1111/j.1529-8817.2006.00310.x

12 pages, 7 figures, 2 tables Our pigment analyses from a year-long study in the coastal Beaufort Sea in the western Canadian Arctic showed the continuous prevalence of eukaryotic picoplankton in the green algal class Prasinophyceae. Microscopic analyses revealed that the most abundant photosynthetic cell types were Micromonas-like picoprasinophytes that persisted throughout winter darkness and then maintained steady exponential growth from late winter to early summer. A Micromonas (CCMP2099) isolated from an Arctic polynya (North Water Polynya between Ellesmere Island and Greenland), an ice-free section, grew optimally at 61C–81C, with light saturation at or below 10 lmol photons .m-2 . s-1 at 0ºC. The 18S rDNA analyses of this isolate and environmental DNA clone libraries from diverse sites across the Arctic Basin indicate that this single psychrophilic Micromonas ecotype has a pan-Arctic distribution. The 18S rDNA from two other picoprasinophyte genera was also found in our pan-Arctic clone libraries: Bathycoccus and Mantoniella. The Arctic Micromonas differed from genotypes elsewhere in the World Ocean, implying that the Arctic Basin is a marine microbial province containing endemic species, consistent with the biogeography of its macroorganisms. The prevalence of obligate low-temperature, shade-adapted species in the phytoplankton indicates that the lower food web of the Arctic Ocean is vulnerable to ongoing climate change in the region This research was supported by the Natural Sciences and Engineering Research Council of Canada; the Strategic Science Fund from Fisheries and Oceans, Canada; the Japan Marine Science and Technology Center, Tokyo, Japan; the Canada Climate Action Fund; ARTIC (REN2001-4909-E/ANT, MCyT) and ESTRAMAR (CTM2004-12631/MAR, MEC) Spain; GENmMar (CTM2004-02586/MAR), European Union; and Fonds québécois de recherche sur la nature et la technologie, Québec, Canada Peer reviewed