The effects of the winter of 1962/63 on the british marine fauna

1. During the exceptionally cold winter of 1962/63 the south east coasts of Great Britain suffered the coldest conditions, but the coasts of Hampshire and Dorset, the Bristol Channel and parts of North Wales the greatest negative anomalies.

2. Northern forms were not generally seriously affected, but some Celtic and southern forms suffered very high mortality in the intertidal zone, particularly in embayed situations in the areas mentioned above.

3. Southern forms limited to exposed western promontories did not suffer much damage; marine algae were also little affected.

4. Death was caused, not only as a direct result of exposure of the tissues to extreme cold, but also from the general lowering of the animals' activity; for example, failure to remove silt by ciliary action, to cling to rock surface, and to burrow, led to many deaths.

5. Even where high mortality was experienced, a few, perhaps more resistant, individuals of the species generally survived in favourable habitats, so that distribution limits were little affected. Adaptive behaviour played an important part in the survival of many littoral forms.