From Science Daily a report on the increasingly worrying state of the world’s oceans and the impact on sea life:
Three of the five largest extinctions of the past 500 million years were associated with global warming and acidification of the oceans — trends which also apply today, the scientists say in a new article in the journal Trends in Ecology and Evolution.
Other extinctions were driven by loss of oxygen from seawaters, pollution, habitat loss and pressure from human hunting and fishing — or a combination of these factors.
“Currently, the Earth is again in a period of increased extinctions and extinction risks, this time mainly caused by human factors,” the scientists stated.
While the data is harder to collect at sea than on land, the evidence points strongly to similar pressures now being felt by sea life as for land animals and plants…
The paper in question is behind the pay wall, I’m reading it:
Extinctions in ancient and modern seas. Trends in Ecology & Evolution, 2012; Paul G. Harnik, Heike K. Lotze, Sean C. Anderson, Zoe V. Finkel, Seth Finnegan, David R. Lindberg, Lee Hsiang Liow, Rowan Lockwood, Craig R. McClain, Jenny L. McGuire, Aaron O’Dea, John M. Pandolfi, Carl Simpson, Derek P. Tittensor.
In the coming century, life in the ocean will be confronted with a suite of environmental conditions that have no analog in human history. Thus, there is an urgent need to determine which marine species will adapt and which will go extinct. Here, we review the growing literature on marine extinctions and extinction risk in the fossil, historical, and modern records to compare the patterns, drivers, and biological correlates of marine extinctions at different times in the past. Characterized by markedly different environmental states, some past periods share common features with predicted future scenarios. We highlight how the different records can be integrated to better understand and predict the impact of current and projected future environmental changes on extinction risk in the ocean.
For those more curious, I’d suggest the “Under a green sky: Global Warming, the Mass Extinctions of the Past, and What They Can Tell Us About Our Future” by Peter Ward. It’s a good popular introduction to the topic.
It recounts how scientists came to understand major extinction events, and discusses the role of increased levels of Co2 and ocean acidification in past extinction events. In particular Ward discusses the Permian-Triassic Extinction Event (PET) that occurred around 250 million years ago, when over 90% of all life vanished.
The PET is also referred to as the “Great dying”.