Ancient fish bones reveal impacts of global warming benea...(f@snm.ku dk IBEnghoff@snm.ku dk ; tel: +...)

Brian R. MacKenzie, Technical University of Denmark , Danish Institute for Fisheries Research, Charlottenlund, Denmark; email: brm@difres.dk; tel.: +45-3396-3403

The climate influence the Gulf of Riga fisheries in during the 17th century: Gulf of Riga (Baltic Sea) fisheries in the late 17th Century

The exploited fish population in the Gulf of Riga was very different in the beginning of the 17th century from what is seen today. Archival evidence reveal that the timing of the fishing season, and species composition and, to an extent, the amounts of fish catches in the Gulf of Riga are strongly linked to climate dynamics.

The time-period 1675-1696 belongs to the coldest period of the Little Ice Age. During that time, fishing in the Gulf of Riga took place at more than 20 localities along the whole coast of the basin and was therefore an important livelihood at these times. Herring, flounder and eelpout (considered to be cold-tolerant species) formed the majority of the catch while the importance of species such as perch, pikeperch and various cyprinids, which prefer warm-water and are nowadays relatively widespread, was less than 1% of the catches.

Herring were in the coastal areas from the end of March to November. The highest catch was in todays terms taken during the warm season - June and July. This should be considered as a direct effect of severe winters, due to which the ice-cover melted relatively late and therefore, massive herring migration to spawning areas near the coast was shifted later in the season.

During the period studied, two sub-periods were identified: 1675-1683 and 1685-1696. Winters were more severe during the second period, and as a result, herring fishing seasons started later due to a shift in the timing of herring spawning in the summer months. As a result, the window where fi
'/>"/>