Ascophyllum nodosum is commercially harvested in the southwestern parts of Nova Scotia. Here the hypothesis is evaluated that harvesting results in a reduction in the abundance of Vertebrata lanosa, an obligate epiphyte of A. nodosum. Sampling at 10 harvested and 16 non-harvested sites showed that percent cover and frequency were significantly lower at harvested sites (i.e. 5.4±4.0 and 0.6±0.7% cover, and 61±24 and 21±18% frequency for non-harvested and harvested sites, respectively). Vertebrata lanosa is suggested as a useful indicator of ecological integrity at harvesting sites.
Phylogenetic relationships of the fungal symbiont of two brown algae were evaluated in the context of host diversity using ribosomal large subunit (nuLSU) sequences. Phylogenetic analysis indicates that Mycophycias ascophylli (phycobionts Ascophyllum nodosum, Pelvetia canaliculata) is misclassified in Verrucariales (Eurotiomycetes). There was no evidence for speciation of M. ascophylli within its two hosts, nor evidence for geographic differentiation between the eastern and western Atlantic Ocean and the White Sea (Arctic Ocean). The placement of M. ascophylli in Capnodiales (Dothideomycetes) will require a reclassification of this species, and calls into question the current classification of the other species of Mycophycias, M. apophlaea.