Sea ice, climate, and Icelandic fisheries in the eighteenth and nineteenthcenturies

The expansion and subsequent decline in catches in many fisheries of the wo rld during the 20th century suggest that the history of fisheries needs our urgent attention. Analysis of environmental effects on fisheries in the pa st (when overfishing was not an issue) may cast light on current concerns a bout declining fish stocks. Primary documentary evidence from Iceland was u sed for preliminary investigations into correlations between sea-ice extent , sea temperatures, ocean currents, and cod fishing, and hence between seve re weather and the decline of Icelandic fisheries in the past. The sources suggest that fishing was generally successful in Iceland during the medieva l period and well into the 16th century. However, in the 17th through the 1 9th centuries, the fisheries failed on numerous occasions, sometimes for se veral years. The causes of these failures were complex. Climate likely play ed a part, and this was certainly the perception of contemporary writers; h owever, socioeconomic factors were also involved.