| Summary: | Metadata record for data from ASAC Project 2914 See the link below for public details on this project. Can animals raft between countries on floating seaweed? We aim to answer that question using powerful genetic tools. We can tell whether gene flow is strong between populations of animals by comparing their mitochondrial DNA; this could show us whether animals from one species in New Zealand are isolated from individuals of the same species in Chile. If they are not isolated, how are they managing to maintain gene flow? We know there are many millions of clumps of floating seaweed in the Southern Ocean, and these might provide a means of intercontinental travel for a range of small invertebrates. Project objectives: The primary objective of the project is to determine the effectiveness of rafting as a dispersal mechanism for sessile and semi-sessile organisms around the Southern Ocean using genetic tools. The secondary objectives, by which the primary objective will be addressed, are: - to examine the biogeography of bull kelp (Durvillaea antarctica) and its holdfast fauna around the Southern Ocean - to undertake genetic analysis of a wide range of macroalgal (seaweed) species throughout the Southern Ocean to assess 1) whether sea ice indeed extended further north than previously believed, and 2) the ecological and evolutionary impacts of historic ice scour on Southern Ocean islands. - to determine which holdfast invertebrates are the most common and ubiquitous in holdfasts of Durvillaea antarctica around the Southern Ocean - to compare the genetic structure of populations of both the kelp itself, and select invertebrate taxa* from its holdfasts, on a number of spatial scales: --- genetic variation at HOLDFAST level: are members of a single species, e.g., the isopod Limnoria stephenseni, closely related within a single holdfast? --- genetic variation at SITE level: are members of a single species, e.g., Durvillaea antarctica itself, closely related at one site? In this case, a 'site' means a single intertidal ...
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