North Sea cod 'doomed by climate change'

Cod are doomed to disappear from the North Sea because of climate change and not just as a result of over-fishing, researchers have discovered.

In the past 40 years the average temperature of the North Sea has increased by 1C with catastrophic effects on its delicate eco-systems.

Species of plankton, on which cod larvae feed, have moved away in search of cooler waters.
The decline in cod stocks has led to an explosion in the populations of crabs and jellyfish, on which the adult fish feed. The shortage of predators at the top of the food chain has had a knock-on effect on flat fish, such as plaice and sole, whose offspring are eaten by crabs.

The cumulative consequences of warming for the North Sea have been spelt out in detail in the study published yesterday in the Proceedings of the Royal Society Biological Sciences journal.

Richard Kirby, a Royal Society Research Fellow at the University of Plymouth, and Gr