Team: Shahar Chaikin

Meet Shahar who recently started a postdoc position with Araújo Lab at the MNCN-CSIC.

Can you share a bit about your academic and research background?

I hold a BSc in marine biology and a PhD in marine ecology and have a broad interest in the effects of global change on marine organisms with a particular interest in marine fish. I am highly enthusiastic about spending time underwater as it is priceless and promotes generating new questions and hypotheses. Over the years I gained experience in sampling fish communities, mostly in the Mediterranean Sea and Red Sea. While working at the local scale increases my understanding of how ecosystems are structured it may raise difficulties in generalizing conclusions. Thus, I am also enthusiastic about macroecology. Currently, I am funded by a two-year grant from the Israeli Council of Higher Education to study the effects of marine heatwaves on fish populations worldwide.

What specific research projects have you been involved with in the past, and what role did you play?

During my bachelor’s, I independently gathered data on threatened batoid coastal breeding aggregations in the eastern Mediterranean. This work matured into a scientific paper and served as a basis for a batoid monitoring program within a marine protected area. With a recently completed PhD, I published seven papers, five as lead author. I studied marine species depth shifts across the Mediterranean Sea and the relationship between depth shifts and abundance shifts in a hotspot of warming. I also focused on alien species and studied, using fieldwork, properties associated with successful biological invasions in an attempt to forecast the next invaders in the eastern Mediterranean. By observing numerous video samples, I was intrigued by the behavior of fish and their interactions. This led me to quantify the impact of invasive species on other co-occurring species. Further, I led a project in the international working group of the Quebec Center for Biodiversity Science, investigating the relationship between species range shift velocities and local abundance changes. Beyond academia, I gained hands-on experience in marine conservation by leading a batoid monitoring program and writing reports for the Israeli Nature and Parks Authority, thus assisting in science-based decision-making.

What are your primary research interests, and how did you become interested in these areas?

I am interested in elucidating the impacts of climate change on fish species (e.g., range shifts and abundance changes) across different scales. Coming from the eastern Mediterranean, a hotspot for climate change and biological invasions, I witnessed the constant changes happening in marine ecosystems, especially the accumulating evidence of species range shifts alongside dramatic environmental changes. These changes fueled my curiosity, and elucidating their impacts is crucial for developing science-based conservation plans in an era of rapid change.

What will you be working on in our research group, and what are your goals for this project?

I am leading a project aimed at explaining the impact of marine heatwaves on fish species worldwide. I aim to analyze heatwaves at numerous locations across the world’s oceans and associate their impacts on local populations. Ecological progress taught us that the location of a population with respect to the species range may harness a lot of variation in species response to climate change. I aim to compile large datasets of fish biomass, abundance, and occurrences alongside global climatic models. Hopefully, this project will manage to estimate population-level responses to marine heatwaves for more than 1000 fish species across vast parts of the oceans, thus generalizing their impact.

How does your current research align with the overall objectives of our research group?

My research directly addresses the core themes of the group’s aim by investigating the effects of a major global change driver, marine heatwaves, on marine biodiversity across broad spatial scales. My overarching goal will focus on informing conservation strategies and improving our ability to forecast the future of marine fishes.

Are there any particular challenges you anticipate facing in your current research? How do you plan to address them?

Working on a macroecological scale poses tremendous challenges. Naming a few, I will compile datasets that are not perfectly designed to my question of interest. However, this is part of the challenging and most interesting part. I will have to elucidate the effects of marine heatwaves on fish populations using several perspectives and temporal scales. These may include associating heatwaves with the nearest biological samples using either daily or annual scales. Further, extreme weather events can be measured at multiple facets (e.g., cumulative intensity, duration, rate of onset, etc.,). Hence, I will have to carefully predict and test how each of these may impact fish populations at different positions across the species range.

What skills or knowledge are you hoping to develop during your time in this research group?

I am keen to create new connections and collaborate with researchers in the group, and the MNCN-CSIC, hopefully coming up with new research lines. I wish to get increased experience with the extraction and handling of large climatic data and improve my statistical toolkit (e.g., getting deeper into Bayesian stats). Importantly, I wish to come up with new insights regarding the impact of marine heatwaves on species and communicate my findings to a broad type of audience.

Where do you see your research taking you in the next five years?

Hopefully, it will allow me to utilize vast sets of biological, climatological, and anthropogenic data to elucidate how global change is changing marine ecosystems and their services but at the same time offer guidelines for science-based decision-making and balancing human society and nature.

Are there any particular conferences, journals, or professional networks you are keen to engage with through your research here?

Starting in 2025, I am participating in a working group focused on the effects of range shift velocities on species across both the oceans and terrestrial environments (German Centre for Integrative Biodiversity Research). I wish to participate in Spanish conferences to increase the new local community that I am now a part of. At the same time, I look forward to participating in the International Biogeography Society, Species on the Move, and the Effects of Climate Change on the World’s Oceans.

What do you think are the most pressing questions or challenges in your research field today?

• What is the relationship between fish population size and marine heatwaves and can it be generalized?
• What are the consequences of range shifts on species persistence?
• Which species and populations are about to increase in the face of global change and which are about to decline?
• What actions are needed or recommended to maintain ecosystems’ functioning and preserve a sufficient level of available services?

How do you stay updated with the latest developments and research in your area of interest?

I try to invest time every week in reading new papers in my field. I follow researchers with whom I have commonalities and occasionally review papers for different journals.

Can you recommend any groundbreaking or influential papers/books in your field that you think everyone should read?

Lawton, J. H. (1999). Are there general laws in ecology? Oikos 84(2): 177-192

Outside of research, what are your hobbies or interests?

My greatest hobby is being immersed underwater. It always surprises me how wild life can get when we simply wear a mask and a snorkel. It immediately connects me with nature, relaxing me, and reminds me how beautiful life can be. Now in the Comunidad de Madrid, I take advantage of the mountains and proximity of nature to travel outside.

How do you balance your research commitments with your personal life?

Well, I have a two-year-old daughter, she is taking good care of me balancing my work and life, and reminds me that every day we should spend some time being present right here and a bit less on predictions of the future. I try to spend the first half of the day working and the second half for my family and myself.

Are there any non-research activities or groups within our institution or community that you’re interested in joining?

If there are hiking or outdoor activities I think it can be a good opportunity to create new connections.