Fiona Tomas Nash, PhD

I graduated with a PhD in Ecology at the University of Barcelona in 2004 and have pursued several postdocs in the US and Spain (Scripps Institution of Oceanography, Bodega Marine Laboratory, University California Davis, Ceab – CSIC). I am a Tenured Scientist at Imedea (UIB-CSIC, Mallorca, Spain).

The theme of my research is to understand the processes and mechanisms that regulate the structure and functioning of marine benthic systems, with particular emphasis on how human activities transform them. To answer these questions I work across different levels of organization (individual, population, community, ecosystem) and I combine strong quantitative field and laboratory experimentation with large-scale field comparisons (temporal and spatial) and fine-scale chemical and molecular analyses. In addition to conducting basic ecological research, I am concerned with applying my findings towards improving the conservation of marine coastal ecosystems.

My research focuses mainly on Coastal systems dominated by Aquatic Macrophytes (CAM) which have a fundamental role as habitat-forming species and perform key ecological functions at the land-sea interface. Seagrass beds and algal forests, for instance, have key ecological functions (e.g. habitat, nutrient cycling) that provide critical ecosystem services (e.g., global carbon sequestration, water quality, shoreline protection, fisheries). I have focused a significant part of my work on studying the ecological consequences of human activities such as overfishing, eutrophication, and the introduction of non-native species, on the structure and function of CAM-based ecosystems. I am interested in plant ecology (e.g., ecophysiology, population dynamics), but largely focus on anthropogenic effects on modifying different aspects of trophic interactions (predator – prey, plant – herbivore), because they are a fundamental process governing ecosystem structure and function as well as species evolution.

Throughout my research I have found that the establishment of productive collaborations is fundamental for the advancement of science and knowledge. I always aim to develop an engaging and collaborative team environment with other researchers and students that encourages and enhances excellence in research.

List of recent / present projects:

  • Ecological functioning and resilience of seagrass meadows and algal forest.

  • Influence of human stressors (e.g. warming, ocean acidification, eutrophication) on plant-herbivore interactions.


  • Seagrass restoration and seedling ecology


  • Seagrass microbiomes


  • Detection, spread, ecology, impacts, and control of invasive species.


  • Tropicalization of temperate ecosystems