Past extinctions inform marine policy
Amidst growing concerns over the mass extinction of marine species, the United Nations is discussing a system of governance for the world's oceans. Can three mass extinctions between 260 and 200 million years ago help show what the future may hold in store? Vigorous research has revealed much about how an ecosystem responds to stress. However, most of this work has been conducted in the tropics, where biodiversity is at its greatest. Much less is known about the impacts on higher latitudes of our planet. The BOREX project determined whether marine ecosystems suffered more due to past environmental changes at high latitudes, mid latitudes or in the tropics. To achieve this, scientists collected data from the island of Spitsbergen in the Arctic Ocean, where the records of mass extinctions have been investigated. Researchers compared their findings with existing evidence from lower latitudes to discover if there were latitudinal patterns of extinction and recovery. They also wished to determine if climatic 'tipping points' coincided with extinctions. Their findings will help improve predictions of the response of ecosystems to future climates. Fossils from across the Middle Permian and Permian-Triassic extinctions were collected from key geological sites in Spitsbergen and examined. Geochemical and palaeontological studies indicated that the Middle Permian extinction was at least as severe (and extremely abrupt) in the high latitudes. The end-Permian extinction may have struck first in the high latitudes. The total loss of carbonates in the region is consistent with ocean acidification stresses, which are particularly threatening to cooler waters of the Arctic regions (cool water absorbs more CO2). These findings will have significant implications for scientists working on past and present environmental change and may affect ocean governance policy. The implication is that high-latitude ecosystems could suffer more as a result of recent and future climate change and in particular acidification stresses. Therefore, the best policy may be to invest now in added protection for these regions to ensure a healthy, high-latitude marine ecosystem.
