Isabel Leon y Leon
I am broadly interested in the ecology of surface ocean species and how they change through time. I’m currently focused on nannoplankton, which are protists that form calcareous plates. Nannoplankton play a very important role in the history of the surface ocean because they are ubiquitous and preserve easily in ancient and modern oceans. By understanding how they react to oceanic changes in the past, we might be able to predict how they may react in the future.
During the Palecoene Eocene Thermal Maximum (PETM), the nannoplankton surprisingly continued to survive despite rapid global warming. The coastal environment has not been well studied and this might provide a vital key to understanding the nannoplankton response to climate warming. I will be looking at a transect from the shelf, which has the added fortune of containing an expanded section the PETM due to increased sedimentation rates.
My research is focused on the planktonic foraminifera from the Paleocene-Eocene thermal maximum, and deducing any changes in assemblage structure and ecology in samples from the coastal plain. I have been closely investigating the assemblages surrounding dissolution events, to draw some conclusions about fluctuations in oceanic chemistry during this time. Additionally, I am closely studying the presence and location of planktonic foraminifera excursion taxa to understand how and why they evolved during the PETM.
I am interested in how changes in ocean chemistry impact the organisms that live in the ocean. More specifically, more work focuses on how increasing carbon dioxide levels in the atmosphere affect ocean chemistry by lowering the pH, a process known as ocean acidification. I study calcareous plankton that live in the surface oceans. These plankton are near the base of the food chain and therefore changes in their populations have the potential to affect the whole ocean system. I am studying ocean acidification in the modern and in the Cretaceous.
In the modern, I am looking at pteropods which are tiny swimming molluscs that make their shells out of aragonite, a more soluble form of calcium carbonate. Because of that, these organisms are at high risk of being affected by ocean acidification. I am using a nano-CT scanner to image these organisms and make a modern database of pteropods to which future changes can be compared.
The second time period I will study is the Cretaceous, specifically the Cenomanian –Turonian boundary (~93Ma). At this time there was a lot of volcanism and so carbon dioxide levels were increasing, similar to the situation that we see today (although at a slower rate). I am interested in how biota were affected by past changes in ocean chemistry to help understand what may happen in the future.