Generic placeholder image I am a Postdoctoral Scholar at Florida State University working in coastal systems and marine biodiversity in the Dr. Rassweiller 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 the field of quantitative ecology examining the environmental and ecological drivers of change in coastal communities and I work 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 (Stazione Zoologica Anton Dohrn, Oregon State University and Universidad Nacional Autónoma de México) 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

  • [8] Lester, S.E., Dubel, A., Hernán G., McHenry, J. and Rassweiler A., (2020): Spatial planning principles for marine ecosystem restoration. Accepted in Frontiers in Marine Science
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    Abstract: Coastal and marine ecosystems characterized by foundation species, such as seagrass beds, coral reefs, salt marshes, oyster reefs, and mangrove forests, are rich in biodiversity and support a range of ecosystem services including coastal protection, food provisioning, water filtration, carbon sequestration, recreational opportunities, cultural value, among others. These ecosystems have experienced degradation and a net loss of total area in regions around the world due to a host of anthropogenic stressors, resulting in declines in the associated ecosystem services they provide. Because of the extensive degradation in many locations, increasing attention has turned to ecosystem restoration of these marine habitats. Restoration techniques for marine and coastal ecosystems are generally more expensive when compared to terrestrial ecosystems, highlighting the importance of carefully selecting locations that will provide the largest return on investment, not only for the probability and magnitude of restoration success, but also for ecosystem service outcomes. However, site selection and spatial planning for marine ecosystem restoration receive relatively little attention in the scientific literature, suggesting a need to better study how spatial planning tools could be incorporated into restoration practice. To the degree that site selection has been formally evaluated in the literature, the criteria have tended to focus more on environmental conditions beneficial for the restored habitat, and less on ecosystem service outcomes once the habitat is restored, which may vary considerably from site to site, or with more complex landscape dynamics and spatial patterns of connectivity. Here we 1) review recent (2015-2019) scientific peer-reviewed literature for several marine ecosystems (seagrass beds, salt marshes, and mangrove forests) to investigate how commonly site selection or spatial planning principles are applied or investigated in scholarly research about marine ecosystem restoration at different spatial scales, 2) provide a conceptual overview of the rationale for applying spatial planning principles to marine ecosystem restoration, and 3) highlight promising analytical approaches from the marine spatial planning and conservation planning literatures that could help improve restoration outcomes. We argue that strategic site selection and spatial planning for marine ecosystem restoration, particularly applied at larger spatial scales and accounting for ecosystem service outcomes, can help support more effective restoration.

  • [7] Rassweiler, A., Dubel, A., Hernán, G., Kushner, J.D., Caselle, J.E., Sprague, J.L., Kui, L., Lamy,T., Lester, S.E., Miller. R.J., (2020): Roving divers surveying fish in fixed areas capture similar patterns in biogeography but different estimates of density when compared with belt transects. Accepted in Frontiers in Marine Science
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    Abstract: Fish abundance and diversity are core measurements taken by many nearshore marine monitoring projects. The most common approaches for counting fish include belt transects and timed counts by roving divers, each with its own limitations. Here we evaluate a fish counting method developed by the Channel Islands National Park’s Kelp Forest Monitoring Program (KFMP), in which roving observers make fish counts that are standardized both by the time taken (30 min) and the area sampled (2000 m2 21 ). This method is potentially very useful because it combines an advantage of simple timed counts – the ability to rapidly sample a large area – with the potential to calculate area-specific density of fish, not just their relative abundance. However, the method has not been comprehensively evaluated and it is uncertain whether fish can effectively be counted in such a large target area within the allotted time. Fortunately, many sites surveyed with this method are also sampled with a more standard fish counting approach of belt transects, both by the KFMP and by the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO). Here we compare estimates of fish density obtained through the area-standardized roving diver method and belt transect methods. In paired samples we find substantial and species-specific differences in densities estimated by each method. Considering all fish taxa together we find that roving divers are likely under-sampling the target area. Despite considerable species-level variation, the different methods produce similar estimates of average diversity and find similar regional and temporal patterns in fish abundance, demonstrating that they can successfully be used in parallel even if the datasets cannot be easily combined. These analyses can guide the interpretation of roving diver data for basic research and management decisions.

  • [6] Hernán G., I. Castejón, J. Terrados and F. Tomas, (2019): Herbivory and resource availability shift plant defense and herbivore feeding choice in a seagrass system. Oecologia, pp 1-14, Link
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    Abstract: Numerous hypotheses have been posited to explain the observed variation in plant defense strategies against herbivory. Under resource-rich environments, plants are predicted to increase their tolerance (limiting resource model; LRM) and, while the resource availability hypothesis (RAH) predicts a decrease in constitutive resistance in plant species growing in resource-rich environments, at the intraspecific level, plants are predicted to follow an opposite pattern (intraspecific RAH). Furthermore, the effect of multiple factors in modulating plant defense strategies has been scarcely explored and is more difficult to predict. Our aim was to understand how plant defense traits respond to herbivory, resource availability and their interactions, and to assess the effects on plant palatability. To this end, we performed an in situ factorial experiment at two sites simulating three herbivory levels and two nutrient availability conditions with the seagrass Posidonia oceanica. Additionally, we performed a series of feeding experiments with its two main herbivores. While plants decreased their constitutive resistance under nutrient fertilization (contrary to intraspecific RAH but in accordance to the RAH), and did not increase allocation to tolerance (likely due to resource limitation, LRM), simulated herbivory induced resistance traits. However, we found no interactive effects of nutrient fertilization and herbivory simulation on plant defense. Both herbivores responded similarly to changes in plant palatability, strongly preferring nutrient-enriched plants and non-clipped plants. This work highlights the need to better understand the drivers of plant defense intraspecific variability in response to resources, particularly in habitat-forming species where changes in plant traits and abundance will cascade onto associated species.

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