A DNA barcode survey of Haida Gwaii kelp (Laminariales, Phaeophyceae) reveals novel ecological and distributional observations and Saccharina druehlii sp. nov.

Abstract

A DNA barcode survey using mitochondrial COI-5P and nuclear internal transcribed spacer (ITS) markers of kelp from Haida Gwaii, British Columbia, has uncovered 18 genetic groups encompassing 17 morphospecies. The discrepancy derived from collections identified in the field as Saccharina sessilis (C.Agardh) Kuntze, which formed two distinct clusters in molecular (both mitochondrial COI-5P and nuclear ITS) analyses leading to the proposal of Saccharina druehlii sp. nov. The morphospecies listed in the literature for this region (∼25), but not found during our survey (8) were accounted for in previous molecular studies that have synonymized taxa, viz., from six to a single species of Alaria, or involve uncertain reports for two Laminaria spp. We did not collect Eisenia arborea Areschoug, which with its distinctive morphology would represent bona fide records for this region. This species was previously reported at only two locations in Haida Gwaii, suggesting that it is rare and restricted in distribution in this flora yielding a total of 19 species of Laminariales. In addition, novel distributional and ecological observations are discussed for the kelp in Haida Gwaii.