title: Protists in Arctic drift and land-fast sea ice.
abstract: Global climate change is having profound impacts on polar ice with changes in the duration and extent of both land-fast ice and drift ice, which is part of the polar ice pack. Sea ice is a distinct habitat and the morphologically identifiable sympagic community living within sea ice can be readily distinguished from pelagic species. Sympagic metazoa and diatoms have been studied extensively since they can be identified using microscopy techniques. However, non-diatom eukaryotic cells living in ice have received much less attention despite taxa such as the dinoflagellate Polarella and the cercozoan Cryothecomonas being isolated from sea ice. Other small flagellates have also been reported, suggesting complex microbial food webs. Since smaller flagellates are fragile, often poorly preserved, and are difficult for non-experts to identify, we applied high throughput tag sequencing of the V4 region of the 18S rRNA gene to investigate the eukaryotic microbiome within the ice. The sea ice communities were diverse (190 taxa) and included many heterotrophic and mixotrophic species. Dinoflagellates (43 taxa), diatoms (29 taxa) and cercozoans (12 taxa) accounted for ~80% of the sequences. The sympagic communities living within drift ice and land-fast ice harbored taxonomically distinct communities and we highlight specific taxa of dinoflagellates and diatoms that may be indicators of land-fast and drift ice.
authors.affiliation: Québec-Océan, Département de Biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec, G1V 0A6, Canada.
authors.forename: André M
authors.initials: AM
authors.lastname: Comeau
authors.affiliation: Institut des Sciences de la Mer (ISMER), Université du Québec à Rimouski, Rimouski, Québec, G5L 3A1, Canada.
authors.forename: Benoît
authors.initials: B
authors.lastname: Philippe
authors.affiliation: Québec-Océan, Département de Biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec, G1V 0A6, Canada.
authors.forename: Mary
authors.initials: M
authors.lastname: Thaler
authors.affiliation: Institut des Sciences de la Mer (ISMER), Université du Québec à Rimouski, Rimouski, Québec, G5L 3A1, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Gosselin
authors.affiliation: Research & Collections, Canadian Museum of Nature, Ottawa, Ontario, K1P 6P4, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Poulin
authors.affiliation: Québec-Océan, Département de Biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec, G1V 0A6, Canada.
authors.forename: Connie
authors.initials: C
authors.lastname: Lovejoy
keywords: Arctic; drift ice; eukaryotes; land-fast ice; pyrosequencing; sea ice; sympagic