Perch in the coastal area

Coastal perch catches were significantly higher than average in 2023. Based on the population estimate, the Archipelago Sea perch year classes 2016-18 look fairly strong. In 2022, perch abundance and biomass estimates continued to grow.

The decline in fishing effort of perch fishing seems to have levelled off, so catches of coastal perch are likely to remain more or less at the same level in the coming years. If the perch biomass in the Archipelago Sea continues to grow, it will enable a larger catch than before, even if the fishing effort does not increase.

The data reflects the state of the fish population in 2023, updated on 8.8.2024

Rannikon ja saariston ahvenkanta on hyvässä tai kohtuullisen hyvässä tilassa, vuosi 2023

The year class strengths of perch

Based on the latest population assessment carried out with VPA (virtual population analysis), the year-classes 2017-18 of perch[OM(1] in the Archipelago Sea would look fairly strong at this stage. The strength of these year classes is supported by their high share of good catches in 2023 (net catch share of 24% and 39%, respectively). In addition, the share of the year class 2019 was 20%.

Populaatioanalyysin perusteella runsaimmat ahvenvuosiluokat Saaristomerellä syntyivät vuosien 1988 ja 1997 lämpiminä kesinä, jolloin kuhakanta oli suhteellisen pieni. 2000-luvulla lämpimät kesät eivät näytä tuottaneet runsaita ahvenen vuosiluokkia. Vuosiluokat 2016–17 näyttäisivät tässä vaiheessa kohtalaisen vahvoilta, mutta viimeisten vuosien arviot ovat populaatioanalyysissä epävarmimpia. — The year class strengths of perch (based on 3 yr. abundance estimate) and the population size of pikeperch (ages ≥1) in the Archipelago Sea according to a stock assessment with VPA in 1977‒2018. The stock assessment of perch was done using two alternative values for the terminal fishing mortality in 2023 (F): 2/3 or half of the average of the years 2016–2020. The most uncertain are the year-class estimates from the years 2017‒18.

The estimated perch stock size (≥5-year-olds)

According to VPA, the number of individuals in the perch population in the Archipelago Sea in 2022 seems to continue to rise from the trough of 2020, and this still uncertain estimate is supported by the abundance of commercial catches. In 2022, the biomass estimate for the perch population was clearly higher than in previous years and was already approaching the level of the peak years. The average size of perch in commercial fishing has increased (Olin & Raitaniemi 2022b), and the biomass estimate of the perch population has been relatively high since 2009 compared to the estimate of the number of individuals.

Saaristomeren ahvenkannan runsaus on ollut viime vuosina melko pieni populaatioanalyysin perusteella. Sen sijaan biomassa on ollut suhteellisen korkea. — The estimated perch stock size (≥5-year-olds) in numbers and biomass in the beginning of each year in the Archipelago Sea in 1980–2022. The stock assessment of perch was done using two alternative values for the terminal fishing mortality 2023 (F): 2/3 or half of the average of the years 2016–2020. The most uncertain are the population size estimates from the years 2020–2022.

The catch of perch in the commercial fishery, and the biennially estimated recreational perch catch

In 2023, coastal commercial perch catches (900 tonnes) decreased by 8% compared to the previous year, but were still significantly above average (644 tonnes). The annual catch of perch by commercial fishers in the sea area has fluctuated sharply, but has been increasing again since 2018. Perch catches in commercial fisheries increased in the north and decreased in the southern sea areas. In 2023, the Archipelago Sea accounted for 44% of commercial fishing along the coast, the Bothnian Sea for 26%, the Bay of Bothnia for 14% and the Gulf of Finland for 3%. The Kvarken catch share was 9% (83 tonnes).

Merialueen kaupallisen kalastuksen ahvensaalis oli neljänneksi suurin seurantajaksolla. — The catch of perch in the commercial fishery in the Finnish coastal areas in 1980–2023 (Suomenlahti = ICES subdivision 32, Ahvenanmaa ja eteläpuolinen merialue = ICES subdivision 29 except statistical squares 51 and 52, Saaristomeri = statistical squares 47, 51 and 52, Selkämeri = ICES subdivision 30 except statistical square 47, Perämeri = ICES subdivision 31).

Suomenlahdella kaupallisen kalastuksen ahvensaalis ei kasvanut. Vapaa-ajankalastuksen ahvensaalis on moninkertainen kaupalliseen kalastukseen verrattuna, mutta laskusuunnassa. Saaristomerellä kaupallisen kalastuksen ahvensaalis kasvoi rajusti. Vapaa-ajankalastuksen ahvensaalis on moninkertainen kaupalliseen kalastukseen verrattuna, mutta laskusuunnassa. Selkämerellä kaupallisen kalastuksen ahvensaalis kasvoi hieman. Vapaa-ajankalastuksen ahvensaalis on moninkertainen kaupalliseen kalastukseen verrattuna. Perämerellä kaupallisen kalastuksen ahvensaalis kasvoi hieman. Vapaa-ajankalastuksen ahvensaalis on moninkertainen kaupalliseen kalastukseen verrattuna. — The catch of perch in the commercial (light blue columns) in the Finnish sea areas in 1980–2023 and the biennially estimated recreational perch catch (dark blue circles) in 1998–2022. Notice the different scales in commercial and recreational catch as well as between different the sea areas. See Fig. 1 for other information.

The gillnet fishing effort and CPUE of commercial perch fishery

In 2023, the total catch in recreational fishing along the coast was estimated at 1920 tonnes, which was about double that of commercial fishing. In the southern sea areas, the decline in recreational catches seems to have stopped. In the Bothnian Sea, catches of recreational fishing have varied a lot. In the Bay of Bothnia, the catch seems to be rising slightly.

The gillnet fishing effort on perch has decreased in all sea areas, but in the latest years the decline seems to have stopped. In recent years, fishing effort has clearly been highest in the Bothnian Sea and lowest in the Gulf of Finland. Catch per unit effort (CPUE) has been on the rise in all sea areas. In the Archipelago Sea, CPUE of 0.36 kg/net day in 2023 decreased from the peak catch in 2022, but was still significantly higher than average. In the Bothnian Sea and the Bay of Bothnia, CPUEs remained at the high level of previous years. The CPUE in the Gulf of Finland is lower than in other sea areas, 0.17 kg/net day in 2023.

Suomenlahden kaupallisen verkkokalastuksen pyyntiponnistus on laskenut jyrkästi, yksikkösaalis kasvanut viime vuosina. Saaristomeren kaupallisen verkkokalastuksen pyyntiponnistus on laskenut, yksikkösaalis kasvanut rajusti viime vuosina. Selkämeren kaupallisen verkkokalastuksen pyyntiponnistus on laskenut 2008 lähtien, yksikkösaalis on ollut kasvussa viime vuosina. Perämeren kaupallisen verkkokalastuksen pyyntiponnistus on laskenut 2013 lähtien, yksikkösaalis on ollut kasvussa viime vuosina. — The gillnet fishing effort and CPUE of commercial perch fishery (gillnet mesh sizes 36–60 mm as bar lengths (stretched mesh size / 2)) in 1998–2023 in the Finnish sea areas (see fig. 1). Note the different scales in fishing effort in the areas.

Sources

Olin, M. & Raitaniemi, J. 2022b. Merialueen ahven. Julkaisussa: Kalakantojen tila vuonna 2021 sekä ennuste vuosille 2022 ja 2023 : Silakka, kilohaili, turska, lohi, meritaimen, siika, kuha, ahven ja hauki. Luonnonvara- ja biotalouden tutkimus 72/2022: 108-117.

Expert

Mikko Olin

Senior Scientist

+358295322308 mikko.olin@luke.fi