Generic placeholder image I am a postdoc Fellow at the Mediterranean Institute for Advanced Studies working in coastal systems in the Dra. Fiona Tomas lab. My research interest is to understand how environmental factors or other ecological state changes affect the processes and mechanisms of coastal systems at different levels, from individuals to communities, and at different spatial and temporal scales. Most of my work focuses on marine macrophytes and fish communities and my research is motivated by dual goals of advancing ecological knowledge and influencing management decisions. To this end, I take an integrative perspective in physiology and ecology combining observational and experimental approaches, and modelling tools.

My current research is related to seagrass systems examining how ecological changes such as invasive species or human stressors affect them. Also, I am collaborating in a project looking at the dynamics and accumulation of microplastics in these systems.

In my previous postdoc at Florida State University I was working in the Dr. Rassweiller lab using quantitative ecology to examine the environmental and ecological drivers of change in coastal communities and also on improving methods for monitoring marine biodiversity.

In my doctoral work at the Mediterranean Institute for Advanced Studies, I studied the effects that changes in environmental factors (e.g., eutrophication, warming and acidification) have on seagrass-herbivore interactions by examining a wide range of plant responses and at different plant life stages and how some of these changes influenced herbivore behavior. During my PhD I visited different research groups and institutions collaborating with international researchers and I try to extend this collaborative spirit everywhere I work.

I enjoy sharing my research with the public and inspiring students. I have participated in outreach activities such as lab open doors and women in science events and judged regional science fairs. Also, I am a scientist you can Skype in the skype a scientist program. For more information see my list of publications and C.V.

Last 3 published papers

  • [13] McHenry J., Rassweiler A., Hernán G., Uejio C.K., Pau S., Dubel A.K., Lester S.E. (2021): Modelling the biodiversity enhancement value of seagrass beds. Divers. Distrib. 00,1-14. doi:10.1111/ddi.13379. Link [PDF]
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    Abstract: Aim: Seagrass beds are declining globally and are increasingly vulnerable to sea level rise (SLR), which could have consequences for the rich biodiversity they support. Spatial variation in the role of seagrass beds in enhancing biodiversity is poorly resolved, limiting our ability to set priorities for conservation and restoration. We aimed to model the biodiversity enhancement value of seagrass beds. Location: Florida Gulf Coast, USA. Methods: We used generalized additive mixed models (GAMMs) to describe the distribution, total cover and species composition of seagrass beds and to estimate their effects on spatial patterns of faunal species richness under three scenarios. Specifically, we: (a) quantified the biodiversity enhancement value of current seagrass beds, (b) inferred the biodiversity value of potential restoration areas and (c) projected potential changes in the distribution and biodiversity enhancement value of seagrass beds due to SLR using low (+0.50 m) and high (+1.0 m) SLR forecasts for 2100. Results: Current seagrass beds supported 43%–64% more species than unvegetated habitats, even when accounting for spatial variability in predicted faunal richness due to other environmental, seascape, temporal and geographic factors. Seagrass restoration in potential habitats would also increase biodiversity in the near-term (i.e., 43%–45% above unvegetated levels). However, model projections indicate that SLR could result in significant losses of current seagrass beds and potential restoration areas, causing contracted distributions and lower seagrass cover. Overall, these changes could result in significant reductions in the enhancement value provided by seagrasses. Although, there could also be many suitable locations for seagrasses by 2100, with some having either comparable or potentially increased enhancement value. Main conclusions: : Our findings highlight the importance of considering spatial variation in biodiversity benefits when planning for seagrass conservation and restoration and when managing the impacts of SLR.

  • [12] Hernán G., M.J. Ortega, J. Henderson, J. Alós, K. Boyer, S. Cimon, V. Combes, M. Cusson, C.M. Hereu, M. Hessing-Lewis, K. Hovel, P. Jorgensen, S. Kiriakopolos, N. Kollars, M.I. O ́Connor, J. Olsen, P.L. Reynolds, J. Ruesink, E. Voigt, F. Tomas (2020): Latitudinal variation in plant defence against herbivory in a marine foundation species does not follow a linear pattern: The importance of resource availability. Global Ecol Biogeogr. doi: Link
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    Abstract: Aim: Studies on latitudinal patterns in plant defence have traditionally overlooked the potential effect that resource availability may have in shaping plant defence. Likewise, latitudinal patterns of tolerance traits have rarely been studied, yet they can be a critical component of plant defence. Therefore, the aim of our study was to examine latitudinal variation in the production of tolerance and resistance traits against her- bivory along a latitudinal range and a natural gradient of resource availability from upwelling conditions. Location: Canada, North America and Mexico. Time period: Summer months of 2015. Major taxa used: The seagrass Zostera marina. Methods: We conducted experiments simulating macroherbivore (e.g., bird, fish) dam- age on the seagrass Z. marina at 10 sites across the Eastern Pacific coast (Canada– Mexico) and Quebec and analysed several traits related to resistance and tolerance strategies against herbivory. In addition, we examined the effects of potential sea- grass changes in defence strategies by performing a series of feeding experiments with mesoherbivores in a subset of sites. Results: We found that eelgrass resistance defences did not follow a linear latitudinal pattern but rather followed a bell-shaped curve which correlated with bottom-up control. In sites with higher nutrient availability, plants allocated resources to tol- erance strategies and had lower resistance traits. Furthermore, seagrasses did not respond linearly to increased herbivory pressure; while they tolerated moderate lev- els of herbivory, they underwent a significant reduction in tolerance and resistance under high herbivory levels, which also made them more susceptible to consumers in feeding experiments. Main conclusions: Our results highlight the importance that nutrient availability has in shaping latitudinal patterns of plant defence against herbivory and show how these defences may not respond linearly to increased herbivory pressure in seagrasses.

  • [11] Máñez-Crespo,J., Tuya, F., Fernández-Torquemada, Y., Royo, L., Pilar-Ruso, Y., Espino, F., Manet, P., Antich, L., Castejón,I., Curbelo, L., de la Ossa, J.A., Hernán, G., Mateo-Ramírez, A., Pereda-Briones, L., Procaccini, G., Terrados, J., Tomas, F. (2020). Seagrass Cymodocea nodosa across biogeographical regions and times: differences in meadow structure and sexual reproduction. Mar. Env. Res. 162 : 105159. Link
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    Abstract: Seagrasses are key habitat-forming species of coastal areas. While previous research has demonstrated considerable small-scale variation in seagrass abundance and structure, studies teasing apart local from large-scale variation are scarce. We determined how different biogeographic scenarios, under varying environmental and genetic variation, explained variation in the abundance and structure (morphology and biomass allocation), epiphytes and sexual reproduction intensity of the seagrass Cymodocea nodosa. Regional and local-scale variation, including their temporal variability, contributed to differentially explain variation in seagrass attributes. Structural, in particular morphological, attributes of the seagrass leaf canopy, most evidenced regional seasonal variation. Allocation to belowground tissues was, however, mainly driven by local-scale variation. High seed densities were observed in meadows of large genetic diversity, indicative of sexual success, which likely resulted from the different evolutionary histories undergone by the seagrass at each region. Our results highlight that phenotypic plasticity to local and regional environments need to be considered to better manage and preserve seagrass meadows.

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