Oceanic Deoxygenation Played Pivotal Role in Triassic–Jurassic Mass Extinction, New Study Finds
A groundbreaking study published in Nature Geosciences has revealed the pivotal role that oceanic anoxia played in the Triassic–Jurassic mass extinction, shedding new light on the impact of ocean deoxygenation on marine ecosystems. The research, led by scientists from Royal Holloway (UK) and including researchers from Trinity College Dublin’s School of Natural Sciences (Ireland) and Utrecht University (Netherlands), has significant implications for current-day marine environments – and serves as a warning that marine ecosystems are more fragile than previously thought.
Using chemical data from ancient mudstone deposits obtained from drill cores in Northern Ireland and Germany, the international research team found that pulses in deoxygenation in shallow marine environments along the margins of the European continent at that time directly coincided with increased extinction levels in those places. This indicates that even localized deoxygenation can lead to widespread ecosystem collapse, making marine environments more vulnerable than previously believed.
Study co-author Micha Ruhl, Assistant Professor in Trinity’s School of Natural Sciences, emphasized the importance of understanding the consequences of global climatic and environmental change and the fundamental Earth system processes that control tipping points in Earth’s ecosystems. The findings from this study are crucial for assessing present-day ecosystem stability and food supply, especially in a world where marine deoxygenation is projected to significantly increase in response to global warming and increased nutrient run-off from continents.
The study also revealed that the global extent of extreme deoxygenation was rather limited during the Triassic–Jurassic period, and similar to the present day. This discovery highlights the sensitivity of marine ecosystems to local and global environmental changes and underscores the potential for locally increased extinction rates to cascade into widespread or global ecosystem collapse and extinctions.
The implications of this research are far-reaching and underscore the importance of addressing the increasing deoxygenation in marine environments today. As the global marine ecosystems become more vulnerable, understanding and mitigating these processes is of paramount importance for safeguarding marine ecosystems and associated food supply. The study of past global change events allows scientists to disentangle the consequences of global climatic and environmental change and constrain fundamental Earth system processes that control tipping points in Earth’s ecosystems.
The findings from this study are outlined in the research article “Globally limited but severe shallow-shelf euxinia during the end-Triassic extinction” published in Nature Geoscience. This research provides valuable insights into the impact of oceanic anoxia on marine extinctions during the Triassic–Jurassic period and serves as a crucial warning for current marine ecosystems in the face of increasing deoxygenation.