Skip to content
Natural Environment Research Council
Grants on the Web - Return to homepage Logo

Details of Award

NERC Reference : NE/X015386/1

The evolution of Chalk Sea ecosystems: biodiversity, resilience and ecological function in a warming world

Grant Award

Principal Investigator:
Professor P Bown, University College London, Earth Sciences
Co-Investigator:
Dr A Jourdan, University College London, Earth Sciences
Science Area:
Earth
Marine
Overall Classification:
Panel C
ENRIs:
Biodiversity
Global Change
Science Topics:
Palaeobiology
Anoxic events
Biodiversity change
Climate change
Fossil record
Isotopic analysis
Marine ecosystems
Mass extinctions
Mesozoic
Palaeoecology
Palaeoenvironments
Anoxic events
Evolutionary history
Fossil record
Marine carbonates
Mass extinctions
Mesozoic climate change
Palaeo proxies
Palaeoecology
Community Ecology
Benthic communities
Biodiversity
Community structure
Ecosystem function
Extinction
Marine communities
Ecosystem Scale Processes
Ecosystem function
Species response
Biodiversity
Abstract:
The amount of carbon dioxide in our atmosphere is already at a level last recorded millions of years ago, and is steadily rising. As our planet continues to warm, scientists are increasingly turning to the fossil record to help understand what marine ecosystems look like and how they were able to function under extreme climate change. One past warming event occurred in the Late Cretaceous about 94 million years ago and is recorded in the British Chalk. Known as the Cenomanian-Turonian Boundary Event, it led to global extinctions and the highest sea levels of the past 250 million years. We will study how marine ecosystems responded to, and were shaped by, this event in unprecedented detail, using the vast and untapped chalk fossil collections of the Natural History Museum, coupled with new fieldwork and a novel method of measuring past temperatures. From the white cliffs of Dover and the rolling downs of southern England, west to Devon and north to Yorkshire, the chalk is an iconic and important part of the British landscape. The rock we see today is made up of the microscopic skeletons of fossil plankton (nannofossils) that lived in the Late Cretaceous Chalk Sea. When they died, their tiny skeletons drifted down to the seafloor forming an ooze that gradually accumulated over time and turned into rock. The skeletons and burrows of other Chalk Sea species were also fossilised, providing a unique record of the entire ecosystem; from the tiniest plankton to the largest apex predators such as sharks and marine reptiles. Owing to its use in building and other industries, numerous chalk pits and quarries were excavated across the UK. These provide a dense network of study sites, enabling us to see how Chalk Sea ecosystems changed in space and time in far more detail than for any other past warming event. Fossils from these sites have been collected for over 200 years and most are housed in the Natural History Museum. One reason why this 'whole ecosystem' archive has not been studied before is that most specimens collected in the 1800s lack details of exactly which part of the chalk they came from, and whether they were alive before, during or after the warming event. We have shown recently, however, that it is possible to extract dust-sized nannofossils from the chalk rock that still adheres to the larger fossils, and to use these plankton to date the specimens. This opens up the fossil collections for study in a way that has not been possible before. We will also undertake new field studies of key sites around the UK to study detailed bed-by-bed changes; counting and identifying all the fossils present to help us understand the whole ecosystem. Usually, such studies only focus on one fossil group, such as ammonites or foraminifera, but we will collect information on everything so we can show how the entire Chalk Sea ecosystem changed through the warming event. Determining the temperature of the Chalk Sea is our final challenge. Traditional techniques require assumptions about the chemical composition of past seawater - something that cannot be known for certain. Instead, we will apply a recently developed chemical technique, called clumped isotope palaeothermometry, to measure the bonds between different, rare, heavy isotopes within the well-preserved shells of fossil animals. These isotopes tend to 'clump' together as temperature falls, and so the bonds between them provide a direct measurement of temperature at the time the shell was formed. By analysing individual growth bands within the shells we will reconstruct seasonal changes across several years, showing how local winter and summer temperatures change with global warming. As well as having the first, detailed study of how Chalk Sea ecosystems changed in response to past warming, we will also compare our findings to projections of how current marine ecosystems might change in response to present-day warming; using the past to test predictions of future change.
Period of Award:
1 Jul 2023 - 30 Jun 2026
Value:
£424,270 Split Award
Authorised funds only
NERC Reference:
NE/X015386/1
Grant Stage:
Awaiting Event/Action
Scheme:
Standard Grant FEC
Grant Status:
Active

This grant award has a total value of £424,270  

top of page


FDAB - Financial Details (Award breakdown by headings)

DI - Other CostsIndirect - Indirect CostsDA - InvestigatorsDI - StaffDA - Estate CostsDI - T&SDA - Other Directly Allocated
£26,993£150,842£60,262£114,489£64,065£3,496£4,124

If you need further help, please read the user guide.