BS10 Marine fish stocks

Coastal freshwater species are monitored in three permanent monitoring sites along the southern coast: in the Archipelago Sea (Brunskär, established in 1991), in the Tvärminne archipelago on the western edge of the Gulf of Finland (2005) and off Helsinki (2005). The monitoring programme mainly concerns freshwater fish species living in coastal areas during the warm season and the indicator includes data for four regularly occurring species: European Perch, Roach, Bream and White Bream.

From year 2002 onwards test fishing has been performed using standard multi-mesh gillnets. The Cyprinids included in the indicator are species that thrive in productive, warm waters. An index of the stock biomass, catch per unit effort in weight (CPUE), used in the indicator, can be regarded as an index of the size of the stock as well as of the nutritional conditions and production potential of the area. CPUE herein stands for catch in weight per net per fishing night.

Marine species. The state of the economically most important marine fish stocks in Finland is mainly assessed with age-based models, which use data on catches and sample-based data on catch composition. Annual estimates of the spawning stock biomasses of these fish stocks are made by the working groups of the International Council for the Exploration of the Sea (ICES). The indicator includes stock estimates for Cod, Baltic Herring and Sprat because of their importance and sensitivity to environmental changes.

ICES stock estimates for Cod are made separately for the western and eastern stock, of which the eastern stock ranges eastwards and northwards from Bornholm Island, reaching also Finland's marine area between Kotka and Vaasa. Only the eastern Cod stock is included in the indicator. Stock estimates for the Baltic Herring occurring also in the Finnish territorial waters are made separately for the combined stock in the Baltic Proper and the Gulf of Finland and for one stock in the Gulf of Bothnia (Bothnian Sea region). Both of these are included in the indicator. ICES does not presently provide estimates for the Baltic Herring stock biomass in the Bothnian Bay region. One stock estimate of Sprat, included in the indicator, is made in the whole of Baltic Sea.


A) Index of stock size (catch per unit effort in weight, CPUE) of four coastal freshwater fish species

Year
Brunskär
Tvärminne
Helsinki
Average
European Perch
Cyprinids
European Perch
Cyprinids
European Perch
Cyprinids
European Perch
Cyprinids
2005
4,21
0,58
1,50
1,02
0,56
1,43
2,09
1,01
2006
4,67
0,47
1,35
2,60
0,79
2,66
2,27
1,91
2007
3,87
0,20
2,57
2,08
0,98
1,66
2,48
1,32
2008
3,33
0,12
1,82
2,09
0,67
1,70
1,94
1,30
2009
3,28
0,03
2,97
1,66
1,23
2,61
2,49
1,44
2010
2,40
0,04
3,62
2,71
0,91
1,94
2,31
1,56
2011
4,07
0,50
4,11
2,75
1,53
3,00
3,23
2,08
2012
3,63
0,15
1,61
4,21
0,87
2,09
2,04
2,15
2013
3,00
0,11
1,30
1,12
1,05
2,83
1,78
1,35


B) Estimates of spawning stock biomass (tons) for the marine fish species

Year
Cod, eastern
Herring, Baltic proper & Gulf of Finland
Herring, Bothnian Sea
Sprat
Year
Cod, eastern
Herring, Baltic proper & Gulf of Finland
Herring, Bothnian Sea
Sprat
1966
169 906
1991
151 619
785 813
588 893
788 000
1967
213 630
1992
93 014
810 631
668 639
1 047 000
1968
226 613
1993
94 466
763 851
609 869
1 361 000
1969
222 793
1994
161 943
772 684
695 231
1 415 000
1970
211 082
1995
187 587
672 307
556 821
1 506 000
1971
195 438
1996
163 571
615 535
523 871
1 931 000
1972
201 793
1997
126 121
582 983
433 653
1 908 000
1973
217 510
198 392
1998
98 027
526 616
388 870
1 429 000
1974
259 367
1 682 759
179 333
1 098 000
1999
86 422
448 599
404 335
1 458 000
1975
312 388
1 575 652
176 487
867 000
2000
93 714
453 937
415 401
1 381 000
1976
330 380
1 367 174
201 390
739 000
2001
88 965
419 189
435 827
1 245 000
1977
322 868
1 519 328
208 772
1 258 000
2002
82 372
438 026
441 088
983 000
1978
367 692
1 441 704
216 858
867 000
2003
76 420
510 068
414 986
834 000
1979
515 040
1 409 571
197 798
498 000
2004
70 545
526 364
429 338
1 078 000
1980
631 593
1 358 308
184 241
311 000
2005
62 193
581 184
511 959
1 343 000
1981
643 064
1 287 411
166 875
268 000
2006
71 182
646 287
518 140
1 120 000
1982
634 759
1 429 329
173 859
341 000
2007
78 590
675 830
570 918
997 000
1983
609 869
1 407 294
204 843
479 000
2008
99 708
678 432
574 353
1 102 000
1984
594 217
1 320 395
262 236
694 000
2009
120 692
738 324
697 320
1 063 000
1985
527 551
1 268 246
288 659
642 000
2010
139 944
764 421
802 109
1 250 000
1986
377 377
1 204 136
337 729
584 000
2011
132 191
730 206
815 046
926 000
1987
322 546
1 149 592
405 550
469 000
2012
153 584
751 456
970 921
905 000
1988
289 816
1 153 449
407 583
419 000
1989
226 613
1 016 674
503 833
443 000
1990
207 316
875 217
587 129
577 000

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