In conjunction with early climate records, catch records from pre-industria
l fisheries are a potentially valuable source of information about the effe
ct of climate on fisheries. This paper describes a test for a temperature e
ffect on an 18th century catch record of Icelandic cod. The results of the
test, which is based on a model that incorporates both internal population
dynamics and a potential temperature effect, support the existence of a tem
perature effect.