Project: Effects of biological invasion on diversity and ecosystem functioning of benthic communities impacted by fishing.

Scientific Background

I graduated in October 2004 in Marine Animal Resource Biology, from the Faculty of Sciences, University of Lisbon (Portugal). During the final year of that degree, I worked with Jan Hiddink, Michel Kaiser and Hilmar Hinz at the School of Ocean Sciences (UWB), on a project entitled “Effects of chronic bottom trawling disturbance on benthic biomass, production and size spectra in different habitats”. We focused on the effects of trawling on the biomass of macrofauna from the North Sea (sandy grounds) and the Irish Sea (muddy grounds), observing how these effects related to changes in community size spectra and secondary production.
After this, I spent one year specializing in Statisitical Methods in Biology, receiving training in Generalized Linear and Non-linear Models, Spatial Data Analysis, Multivariate Statistics and Bayesian Methods. I graduated in June 2005 from the Faculty of Sciences, University of Lisbon (Portugal).

PhD research

I am currently a full-time PhD student. My project is funded by the Portuguese government through the Foundation for Science and Technology (Fundação para a Ciência e Tecnologia). I am investigating the effects of the introduction of the Manila clam (Ruditapes philippinarum, Adams and Reeve) on biodiversity patterns in benthic communities, trying to understand how these relate to ecosystem functioning - namely bioturbation and biogeochemical cycling. Biological invasions, i.e. the successful establishment and spread of organisms outside of their native ranges, can significantly modify biodiversity and ecosystem functioning relationships (BD-EF) through changes in community diversity. Introduced ecosystem engineers (such as the Manila clam) are high impact species because they have additional impacts due to disproportionate contributions to ecosystem function (g.e. bioturbation) and through the modulation of resources to other species populations. Consequent changes to the strength of species interactions (i.e. competition, facilitation, etc) through alteration of resource use and supply add to the impacts of invasion on BD-EF relationships. However, the way through which these changes take place is hard to predict due to the intricate nature and high specificity of invasion processes. Abiotic factors, such as climatic conditions, play a key role in nonindigenous species invasion success - climate can significantly condition ecosystem processes and species interactions, and it is therefore expected that current global climate changes will progressively become determinant factors of biological invasion success rates.

I am therefore trying to understand how biological invasion impacts on benthic systems can modify BD-EF relationships. The study focuses on four coastal lagoons across Europe (Ria Formosa (Portugal), Venice Lagoon (Italy), Bay of Arcachon (France), and Poole Harbour (England)) which have been successfully invaded by the same ecosystem engineer species (the Manila clam). This project is expected to provide a better understanding on how invasion effects propagate across the food-web under the influence of different temperature regimes, with emphasis on the relationship between Manila clam density, native macrofauna diversity, meiofauna diversity, and ecosystem functioning (bioturbation). Potential displacement the grooved carpet shell (Ruditapes decussatus, Linnaeus), native to these systems, as a consequence of invasion is also to be analysed. The project relies strongly on the use of Sediment Profile Imagery (SPI) - a technology which allows for superficial layers of sediment to be photographed. Images obtained in this manner can be used to estimate the depth of the superficial oxic sediment layer, which lies just below the sediment-water interface, which is then used as a proxy for community bioturbation rates (once environmental mixing of sediments has been accounted for).

As a side goal, I am also trying to undestand how changes to sediment habitat, as a consequence of the introduction of a new ecosystem engineer (the Manila clam), can impact on biogeochemical cycling through consequential modification of microbial diversity. I am using terminal-restriction fragment length polymorphism (T-RFLP, a molecular based technique) to observe changes in microbial community composition across the four study areas.

This project is supervised by Prof. Michel Kaiser and Dr. Jan Hiddink (School of Ocean Sciences, Bangor University), and by Dr. Henrique Cabral (Institute of Oceanography, University of Lisbon, Portugal). Dr. Martin Solan (Oceanlab, University of Aberdeen) is also a joint colaborator of the project, as is Dr. Sasa Raicevich (Istituto Centrale per la Ricerca Scientifica e Tecnologica Applicata al Mare, Italy).

Figures (left to right and top to bottom): Prof. Kaiser and myself, sampling in Poole Harbour (2006); the SPI camera in a sand boat in Ria Formosa (2007); Joao Mendes and Dr. Sasa Raicevich manually deploying the SPI camera in the Venice lagoon (2007); sampling gear in clam viveiros of the Ria Formosa (2007); the Manila clam (Ruditapes philippinarum) in the Venice lagoon; the grooved carpet shell /palourde (Ruditapes decussatus) in the Ria Formosa.

Publications

Queirós, A.M., Hiddink, J.G., Hinz, H. and Kaiser, M.J., 2006. The effects of chronic bottom trawling disturbance on benthic biomass, production and size spectra in different habitats. Journal of Experimental Marine Biology and Ecology 335: 91-103.

Hiddink, J.G., Jennings, S., Kaiser, M.J., Queirós, A.M., Duplisea, D.E. and Piet, G.J., 2006. Cumulative impacts of seabed trawl disturbance on benthic biomass, production and species richness in different habitats. Canadian Journal of Fisheries and Aquatic Sciences 63: 721 – 736.

Communications

Poster: Trawling effects on Production and Size Spectra of Benthic Communities in the North Sea, awarded Best Poster prize at the Postgraduate workshop of the MBA, in Menai Bridge, 3-4 April 2004.

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