Where was cod in the ice age?

Friday Seminar by Phil Williamson.



We consider present-day climatic conditions to be ‘normal’. Yet the human species has already survived global temperature changes of around 5°C at least once, and for most of the past million years the Earth has been considerably cooler than it is today. In consequence, European shelf seas, such as the North Sea and the Baltic, are – in geological terms - new and relatively transient habitats, only being available to fish and other marine organisms for a few thousand years. On land, the history of changes in vegetation and animal life in response to glaciation is relatively well-documented, through studies of fossil pollen, insects and other remains. For marine environments, the analysis of foraminifera provides some data; however, little is known on the ice-age distributions of other groups

This talk describes research on the modelled distribution of Atlantic cod Gadus morhua at the last glacial maximum (LGM) around 20,000 years ago, and genetic analyses to test the model simulations. Results indicate that the LGM range of cod was only a fifth of present-day values. However, both models and genetics indicate that cod populations survived on both sides of the North Atlantic. Although relatively simple, it should be possible to use similar approaches to reconstruct the responses of other marine species to past climate change, as well as simulating the impacts of future global warming. The analyses were carried out in collaboration with Geir Ottersen (IMR Bergen/Oslo) and three other research groups in the US and UK.

Other information
The CEES seminar room has a coffee-machine – it is therefore recommended that you come a bit earlier and get yourself a good cup of coffee (for the price of 3 NOK).

Published Feb. 6, 2012 3:48 PM