I investigate the impact of changes in environment and climate on living organisms on various time scales, from millions of years to decades, with my focus on benthic foraminifera (eukaryotic unicellular organisms).  I study their assemblages, as well as trace element and stable isotopic composition of their shells. Foraminifera live in salt or at least brackish water, so I concentrate on the oceans, from the deep sea up into tidal salt marshes. The deep sea is the largest habitat on Earth, supports a high diversity of organisms, but is one of the least known.  I study foraminifera from the deep sea floor, using samples from the International Ocean Discovery Program. I am interested in understanding the development of high-diversity deep-sea faunas through periods of major climate change and mass extinction, such as the mass extinction caused by meteorite impact at the end of the Cretaceous (66 million years ago), which did not affect benthic foraminifera significantly.