Marine ecosystem responses to past climate change and its oceanographic impacts

Dr Richard Stockey, OES; Professor Tom Ezard, OES; Professor Paul Wilson, OES, University of Southampton

Earth’s oceans are warming and losing dissolved oxygen due to human activity. Experiments on modern animals show that the combined impacts of seawater oxygen and temperature are a substantial environmental threat to animal ecosystems. Ocean warming and deoxygenation (anoxic) events are common in the geologic record, and these ancient climate perturbations were often linked to marine extinctions. But many questions remain unanswered.


What were the magnitudes and rates of warming and the ocean oxygenation responses? What proportion of marine species went extinct? Were some taxonomic or functional groups more likely to survive than others?


Most ancient climate events have been studied qualitatively by investigating extinction at the global scale to link biodiversity in the fossil record to oceanographic change.


You will combine computer models of ancient oceans/climate and ecosystems with quantitative palaeobiological methods to make predictions about the impacts of ancient climate change and then test our understanding against the fossil record.


You will study key intervals of Earth history where past climate change is suggested to have impacted marine ecosystems (e.g. Cretaceous oceanic anoxic events) to produce some of the first direct and statistically robust tests of how ocean warming and deoxygenation have impacted animal ecosystems through Earth’s history.



Many of the methods you will use in this palaeobiology and palaeoclimate project are inspired by techniques from modern global change ecology. Applying these modern approaches to Earth history requires that we translate fossil data into meaningful ecological metrics such as regional biodiversity and geographic range size. You will use emerging techniques from quantitative palaeobiology to estimate shifts in geographic range and regional biodiversity for key warming events over the last ~100 million years. Depending on your interests, these palaeobiological analyses will be combined with fossil observations and measurements from the field and/or museum collections.


These new syntheses of biodiversity dynamics will provide novel insights and will further be used to help test competing hypotheses of ancient warming-induced biodiversity dynamics. You will use Earth system (coupled atmosphere-ocean) and ecological models to simulate the responses to warming of 1) marine environmental conditionals that are important to animal physiology (e.g. dissolved oxygen and seawater temperature), and 2) the migration and extinction of marine animal populations in response to temperature, oxygen and food supply. The balance of palaeoecology and climate/ecological modeling will depend on your interests. There will also be scope for conducting model development and/or geochemical analyses if interested.



The INSPIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and hosted in the School of Ocean and Earth Sciences.


Depending on your interests, project specific training will include at least some of:

  • General computer programming (inc. data wrangling, machine learning/statistics, climate file manipulation, spatial models; training in R, with potential additional training in Python, Fortran, Matlab)
  • Supercomputer cluster computing (Southampton IRIDIS5)
  • Quantitative palaeobiology (regional biodiversity, geographic range size, extirpation/extinction, diversification/migration)
  • Earth system modelling (dynamic climate-ocean models using cGENIE and potentially other models)
  • Ecophysiological modelling (e.g. Metabolic Index)
  • Population modelling
  • Stratigraphic palaeobiology (inc. correlation of palaeobiological records, field/museum skills)
  • Sedimentary geochemistry and ocean biogeochemistry
  • International research conference presentations


Eligibility & Funding Details: 

Please see for details.


Background Reading: 

Stockey et al., (2021) Decreasing Phanerozoic extinction intensity as a consequence of

Earth surface oxygenation and metazoan ecophysiology, Proceedings of the National

Academy of Sciences, 18 (41), e2101900118.


Penn et al., (2018) Temperature-dependent hypoxia explains biogeography and severity of end-Permian marine mass extinction, Science, 326 (6419), eaat1327.


Pohl, Ridgwell, Stockey et al., (2022) Continental configuration controls ocean oxygenation during the Phanerozoic, Nature, 608 (7923), 523-527.


Further relevant literature available on request from: [Richard Stockey email]