PhD-positie: Ecophysiology of benthic infauna in estuarine sediments under climate- and anthropogenic stressors

The department of Estuarine and Delta Systems research of the Royal Netherlands Institute of Sea Research (NIOZ) is looking for an enthusiastic PhD candidate to study the ecophysiology of benthic infauna in estuarine sediments under the combined influence of climate change and anthropogenic stressors.

THE INSTITUTE

NIOZ is the national oceanographic institute of the Netherlands. Its principal mission is to perform academically excellent, multidisciplinary, fundamental and frontier-applied marine research and education addressing important scientific and societal questions pertaining to the functioning of oceans, seas and deltas. NIOZ advances fundamental understanding of marine systems, the way they change, the role they play in climate and biodiversity, and how they may provide sustainable solutions to society in the future. NIOZ serves as national marine research facilitator for the scientific community in the Netherlands. In addition to its research and education, NIOZ supports marine-policy development within the national and international context.

THE DEPARTEMENT

The department of Estuarine and Delta Systems (EDS) of NIOZ is based in Yerseke. We study how the interplay between biota, hydrodynamics, sediment dynamics and biochemistry shapes the estuarine, deltaic and coastal environments within the context of natural and human-induced environmental changes. Our department has a multidisciplinary approach that combines state-of-the-art biophysical, biochemical, ecological and physiological measurements and experiments with remote sensing and numerical modelling to create in-depth understanding of the processes that control estuarine and delta systems. One important focus for the department is how our research can create value for society.

THE RESEARCH

Biodiversity loss is a global challenge that threatens ecosystem stability and resilience. Although nature restoration initiatives are expanding, their long-term success remains uncertain, as climate extremes can trigger mass mortality events that reset communities and undermine restoration outcomes. Many nature-based solutions, such as sediment or hydrodynamic manipulations to create or enhance habitats, overlook sediment properties, which may play an important role in buffering or amplifying the effects of environmental stressors such as temperature change and chemical and physical conditions.

This PhD project investigates how sediment characteristics shape the microclimatic conditions experienced by benthic infauna during extreme events, with the aim of advancing climate-resilient restoration practices. By combining field observations with laboratory and mesocosm experiments, exposing organisms to simulated heatwaves across different sediment types (e.g., mud versus sand), the project will quantify temperature and biogeochemical gradients and assess how these influence the performance, stress tolerance, and survival of benthic species such as the common cockle (Cerastoderma edule) that has been shown to be sensitive to heat waves.

Integrating data from estuarine field sites with controlled simulations of marine and atmospheric heatwaves, the research will provide a mechanistic understanding of how sediment dynamics mediate biological responses to environmental stress. This will enable you to assess how climate change and human interventions, such as tidal flat nourishments and managed realignments, affect benthic communities.

The findings will support more effective sediment management and inform the design of climate-adaptive restoration strategies for estuarine ecosystems. In doing so, the project addresses the key question: how do different sediment types buffer or amplify the impacts of climate extremes and shape the vulnerability of benthic communities?

KEY RESPONSIBILITIES

As a PhD candidate, you will:

• Investigate how sediment properties (e.g., grain size, bulk density, silt and organic matter content) influence the thermal and biogeochemical microclimate of intertidal habitats under both typical and extreme conditions

• Conduct fieldwork in estuarine environments, including deploying temperature loggers and operating a microprofiler to measure thermal and chemical profiles of sediments

• Design and execute laboratory and mesocosm experiments examining how sediment type affects the performance, stress tolerance, and recovery of benthic species under simulated heatwaves

• Analyze environmental and experimental data using statistical approaches (e.g., in R)

• Explore interactions between organisms and their environment, such as how benthic species may modify sediment conditions through bioturbation or bio irrigation

• Help assess how sediment characteristics used in management practices (e.g., nourishments, realignments) influence the resilience of benthic communities

• Publish research findings in peer-reviewed journals and present results at national and international conferences

• Contribute to a vibrant and inclusive research culture within the research group

• Mentor and supervise BSc and MSc students in thesis projects and field/laboratory activities.

• Submit and defend a PhD-thesis at the end of the assignment period

THE CANDIDATE

You are a motivated and creative researcher with a strong ambition to pursue a PhD, with a background in marine or estuarine science and a clear interest in coastal ecology, benthic infauna, and climate change. You enjoy working both independently and collaboratively, and bring a critical, proactive mindset to your research.

We are looking for a candidate with:

An MSc degree in marine or estuarine biology, ecology, environmental sciences, biogeochemistry, or a related field

• Experience in quantitative data analysis

• A strong interest in coastal ecology, benthic fauna, and climate change

• Experience with laboratory or (advantageous) mesocosm experiments

• Affinity with fieldwork in coastal or estuarine environments

• Experience with or interest in eco physiological measurements (e.g., growth, respiration, stress responses)

• Excellent English communication skills (written and spoken); interest in science communication or interdisciplinary collaboration is an asset

• A driver’s license valid in the Netherlands and willingness to conduct fieldwork

• Interest in the impacts of human activities on marine ecosystems and in climate-resilient restoration

For this position your command of the English language is expected to be at C1 level. Sometimes it is necessary to submit an internationally recognized Certificate of Proficiency in the English Language. More information can be found here.

WHAT YOU WILL GAIN

You will gain hands-on experience in field sampling, experimental ecology, and data analysis, working at the interface of ecology, physiology, and biogeochemistry. Your research will improve our understanding of sediment–fauna–climate interactions and provide practical guidance for sustainable sediment management and climate-resilient delta design. During your PhD project you will be offered ample opportunities to develop yourself further following an individual training plan.

DELTA CLIMATE CENTER

This PhD project contributes to the mission of the Delta Climate Center by generating fundamental knowledge for climate-proof restoration and strengthening our understanding of estuarine ecosystem resilience. The Delta Climate Center (DCC) in Vlissingen is a new and innovative knowledge center in the field of climate adaptation. It unites science and practice through a unique partnership between the knowledge institutions Scalda, HZ University of Applied Sciences, University College Roosevelt, NIOZ, Utrecht University, and Wageningen University & Research. The core question of the DCC is: how to advance the transition towards sustainable, climate-resilient, and prosperous deltas? With the Zeeland delta as its living lab, the DCC fosters innovative and impactful solutions for future-proof delta’s worldwide.

You will work here You will join the Department of Estuarine & Delta Systems (EDS) at NIOZ in Yerseke, under the supervision of Dr. Brenda Walles and Dr. Emil De Borger. You will also be affiliated with the Marine Animal Ecology (MAE) group at Wageningen University, with Prof. Dr. Tinka Murk as your promotor and Edwin Foekema as co-supervisor. In addition, you will be enrolled in the Wageningen Institute for Animal Sciences (WIAS) graduate school.

You will spend most of your time at NIOZ in Yerseke, with regular visits (approximately once per month) to Wageningen to collaborate with the MAE group. You will also participate in DCC community meetings and events in Vlissingen. In addition, there is the opportunity for a short research stay abroad (e.g., one to two months) with an international partner.

We want to be a transparent institute with a healthy working climate and an inclusive culture, where people from diverse backgrounds and gender bring their talents and further develop these . We aim for inclusive decision-making processes and expect our leadership to show visible commitment, awareness of bias, and cultural intelligence.

CONDITIONS

• Employment of this full-time position at Royal NIOZ is by NWO-I, for a total duration of 4 years. You start with an appointment for the duration of 1 year, that, after a positive evaluation in the 9th month (Go-No go), will be extended to the full period of 4 years. · Salary compliant with scales for PhD candidate (OIOs) CAO-WVOI (Collective Labour Agreement for Dutch Research Institutes).

• An appointment at NIOZ as a PhD candidate means working and learning simultaneously conform the NIOZ PhD policy.

• Your PhD position will include a total of 30 ECTS advanced training according to your personal training and supervision plan.

• 338 annualized holiday hours for a full-time 40-hour work week.

• Pension scheme via ABP, 8% holiday allowance and a year-end bonus of 8.33%.

• 2nd class public transportation travel is reimbursed 100%.

• Employment benefits plan to exchange a portion of your salary for days off or vice versa, or can be used to purchase a bicycle with tax benefits.

• We offer relocation expenses for employees coming from abroad and support with finding accommodation.

MORE INFORMATION

For additional information about this vacancy, please contact Brenda.walles@nioz.nl. For additional information about the procedure, please send an e-mail to working@nioz.nl