Department of Earth, Ocean and Ecological Science Events

Friday 9th March
Start time: 1:00pm
Venue: Jane Herdman Lecture Theatre

Tracing fluid transfer across subduction zones using iron and zinc stable isotopes

This study involved targeting samples from Western Alps ophiolite complexes, interpreted as remnants of serpentinized oceanic lithosphere metamorphosed and devolatilized during subduction. A striking negative correlation is present between bulk serpentinite Fe isotope composition and proportion of ferric iron, with the highest grade samples displaying the heaviest Fe isotope compositions and proportion of oxidised iron. The same samples also display a corresponding variation in Zn isotopes, with the highest grade samples displaying isotopically light compositions. The negative correlation between Fe and Zn isotopes and decrease in ferric iron content can explained by serpentinite sulfide breakdown and the release of fluids enriched in isotopically light Fe and heavy Zn sulphate complexes. The migration of these highly oxidizing sulfate-bearing fluids from the slab to the slab-mantle interface or mantle wedge has important implications for the redox evolution of the sub-arc mantle and the transport of metals from the subducting slab.

Dr Helen Williams, University of Cambridge

Thursday 15th March
Start time: 4:00pm
Venue: Brodie Tower, Room 106

Eco-engineering of the Grey: making space for nature in artificial shorelines

Coastal defence structures are proliferating as a result of rising sea levels and stormier seas. With the realisation that most coastal infrastructure cannot be lost or removed, research is required into ways that coastal defence structures can be built to meet engineering requirements, whilst also providing relevant ecosystem services - ecological engineering. This approach requires an understanding of the types of assemblages and their functional roles that are desirable and feasible in these novel ecosystems. I summarise research carried out by myself and the wider team on eco-engineering and I outline guidelines and recommendations to provide multiple ecosystem services while maintaining engineering efficacy. This work demonstrated that simple enhancement methods can be cost-effective measures to manage local biodiversity. Care is required, however, in the wholesale implementation of these recommendations without full consideration of the desired effects and overall management goals.

Dr Louise Firth, University of Plymouth

Thursday 19th April
Start time: 4:00pm
Venue: Brodie Tower, Room 106

Predicting invasive species impact: old challenges and new approaches

Invasion biology has faced a number of challenges concerning the impacts of invasive alien species.  One such challenge is the development of predictive methodologies that can reliably forecast the ecological impacts of existing, emerging and potential invasive species. These challenges need to be addressed to advance both the fundamental science of invasion ecology and provide practical methodologies that can mitigate invasions. Consequently, the comparison of the classical ‘functional response’ (relationship between resource use and availability) between invasive and trophically analogous native species may allow prediction of invader ecological impact. Indeed it has now been shown that a range of damaging invasive species have consistently higher functional responses than comparator native species. Importantly is has been shown that such heightened responses correlate to a high degree with known field impacts. Ecological impact of new and emerging invaders may therefore be predicted by the magnitude of difference in such functional responses. This seminar will review the work to date, demonstrating how comparisons between invasive and native species allow for testing of the likely population-level outcomes of invasion events for affected species across a broad range of aquatic systems.

Dr Mhairi Alexander, University of West Scotland