Population size and distribution of the Baltic ringed seal (Phoca hispida botnica)

  • Tero Härkönen Swedish Museum of Natural History, Box 50007, S-104 05 Stockholm, Sweden. Mailing address: Höga 160, S-442 73 Kärna
  • Olavi Stenman Finnish Game Research, Box 6, SF-00721 Helsinki
  • Mart Jüssi Estonian Fund for Nature, Box 245, EE-2400 Tartu
  • Ivar Jüssi Estonian Marine Institute, 32 Lai Street, EE-0001 Tallinn
  • Roustam Sagitov St. Petersburg State University , Universitetskaya emb. 7/9 RF-199034, St. Petersburg
  • Michail Verevkin St. Petersburg State University , Universitetskaya emb. 7/9 RF-199034, St. Petersburg
Keywords: Baltic ringed seal, Phoca hispida botnica, abundance, distribution, Baltic Sea

Abstract

The study reviews earlier investigations on the distribution and abundance of ringed seals (Phoca hispida botnica) in the Baltic and presents the first statistically robust results for the entire area. A critical review of earlier counts of ringed seals from the Gulf of Riga and the Gulf of Finland reveals grossly exaggerated population estimates in these regions. This is confirmed by results from the first comprehensive surveys in the entire area carried out during 1994-1996. The estimated hauled-out Baltic population in 1996 was about 5,510 ± 42% (± 95% confidence interval). Of this
estimate 3,945 ± 1,732 (70%) were in the Gulf of Bothnia, 1,407 ± 590 (25%) in the Gulf of Riga and about 150 (5%) in the Gulf of Finland. Numbers in the Gulf of Bothnia have increased since 1988, but there are no data on trends in other areas, although numbers are low and half the local population in the Gulf of Finland may have died in a mass mortality in the autumn of 1991.

Published
1998-06-07
How to Cite
HärkönenT., StenmanO., JüssiM., JüssiI., SagitovR., & VerevkinM. (1998). Population size and distribution of the Baltic ringed seal (<i>Phoca hispida botnica</i&gt;). NAMMCO Scientific Publications, 1, 167-180. https://doi.org/10.7557/3.2986