Functional diversity in extreme marine environments

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There is growing concern over anthropogenic impacts on the deep ocean, home of the world's largest and most poorly known ecosystems. This programme will develop and apply functional ecology approaches in two ecosystems to assess responses to human activities and global changes. Functional diversity is a useful tool for comparing communities in different habitats and regions. The animals endemic to hydrothermal vents on tectonic spreading ridges are adapted to extreme habitat conditions. A Canadian company plans to start deep-sea mining in 2017 in the South Pacific targeting the metal-rich chimney deposits that form much of the habitat at long-lived sites. My work has amassed decades of data on hydrothermal vent diversity and animal characteristics, especially off the Canadian coast. Our work will develop functional trait approaches to compare abundance-based diversity indices at vent sites along the Juan de Fuca/Explorer Ridges. With funded cruises at vent sites off Tonga (one a mining prospect), we will use the refined methods to examine functional diversity between high versus low “quality” mine targets. A third field site lies in another biogeographic region (Mariana) where the same techniques will support a pan-Pacific functional diversity comparison. Studies on key species, particularly the large animals that host symbionts, will extend known functional traits and facilitate inter-region comparisons. We collaborate with other researchers to amass data and test analyses; it will be the first to make a full functional assessment of the hot vent system with an open access trait database. *** One important objective is to assess the functional methods in stressed communities. We will also use another rich dataset to test the same approaches in a different low oxygen/high sulphide setting: a hypoxic basin. Here, intolerant species are at a metabolic disadvantage as hypoxia rises and habitat compresses. We will examine the transition of functional and diversity components of the epibenthos and seek break-points where functions change or disappear. Despite the greater threat of expanding low oxygen/low pH zones on the west coast, relatively little work is available on northeast Pacific species to predict responses to the changes brought by a warming ocean. *** Overall, the programme will help marine ecologists to apply functional approaches by expanding trait databases and testing analytical methods. A better understanding of functional losses in stressed habitats will support selection of management tools. Vent work will contribute to an international effort to develop methods for assessing likely mining effects, particularly in the context of preserving functional and connectivity components in these fragmented habitats. **