Oxygen Starts A Deep-Sea Party & You’re 580 Ma Late

A day ~575 million years ago seemed like any other. Life was simple, not as in life was easy, but organisms were simple creatures. Then, geologically-speaking, BAMM!, complex life forms. Sure they were not the showy creatures of today, but the Ediacara biota (580Ma) of centimeter- to meter-sized eukaryotes, representing both some extant kingdoms and failed experiments, still are intriguing. So what events started the Ediacara party?

To answer this question we go to the Ediacaran animals in deposit on the Avalonn Peninsula in Newfoundland. The community is from a deep seafloor environment, several hundreds of meters deep, from the northern edge of Gondwana. Analyzed samples suggest deep-water anoxic conditions persisted before 580Ma, shifting toward a stable oxic period of a least 15 million years. The process is bit complex so as a list…
1) This shift in oxygen concentrations corresponds with the Gaskiers deglaciation
2) Glacial melting increased nutrient loads in the ocean.
3) This in turn promotes primary production and carbon burial
4) This increases atmospheric oxygen levels.
5) Which allows for oxygen concentrations large enough to allow for respiration of large, multicellular organisms.

Summary of and figures from Canfield et al. (2007, Science)

Dr. M (1801 Posts)

Craig McClain is the Executive Director of the Lousiana University Marine Consortium. He has conducted deep-sea research for 20 years and published over 50 papers in the area. He has participated in and led dozens of oceanographic expeditions taken him to the Antarctic and the most remote regions of the Pacific and Atlantic. Craig’s research focuses on how energy drives the biology of marine invertebrates from individuals to ecosystems, specifically, seeking to uncover how organisms are adapted to different levels of carbon availability, i.e. food, and how this determines the kinds and number of species in different parts of the oceans. Additionally, Craig is obsessed with the size of things. Sometimes this translated into actually scientific research. Craig’s research has been featured on National Public Radio, Discovery Channel, Fox News, National Geographic and ABC News. In addition to his scientific research, Craig also advocates the need for scientists to connect with the public and is the founder and chief editor of the acclaimed Deep-Sea News (http://deepseanews.com/), a popular ocean-themed blog that has won numerous awards. His writing has been featured in Cosmos, Science Illustrated, American Scientist, Wired, Mental Floss, and the Open Lab: The Best Science Writing on the Web.