Cormorant populations in Finland have exploded, causing damage to fish stocks and the profitability of the fishing livelihood.

Omissions

• The explosive growth phase occurred mainly between 1996 and 2009 (10 pairs to 16,000 pairs); since about 2015 the breeding population has fluctuated around a stable high level rather than growing continuously.
• Most recent data before the session date (summer 2025 count, ~31,910 nests) shows the population decreased by about 1% from the previous summer, not an ongoing explosion.
• The claim that cormorants 'destroy' fish stocks and the profitability of the fishing livelihood is scientifically contested: while the 2026 EPRS briefing notes a 'significant and widespread impact' on fish stocks and aquaculture, peer-reviewed studies (e.g. Lehikoinen et al. 2017) find the impact on specific stocks varies and is not uniformly destructive; some official monitoring text (ymparisto.fi) notes that the population has levelled off.
• Sources for the 2025 count (peer.eu and a Syke social-media post) could not be fully opened within the search limit; the 2025 figure relies on search snippets.

Sources

• PrimarySuomen ympäristökeskus / ymparisto.fi — Merimetsoseuranta (Finnish Environment Institute)Suomessa merimetson pesimäkanta kasvoi 10 parista 16 000 pariin vuosina 1996–2009. Linnustomme lähihistoriassa merimetsokannan kasvu on ollut omaa luokkaansa. (In Finland the cormorant breeding population grew from 10 pairs to 16,000 pairs in 1996–2009; the growth is unprecedented in the recent history of our bird fauna.)
• PrimarySTT Info — press release by Suomen ympäristökeskus (Syke): 'Suomen merimetsokanta kasvoi yli kymmenen prosenttia'Kesällä 2024 merimetson pesiä laskettiin Suomessa noin 31 950 kappaletta. Pesimäkanta kasvoi edelliskesästä 14 prosenttia, noin 4 035 pesää. (In summer 2024 about 31,950 cormorant nests were counted in Finland; the breeding population grew 14%, about 4,035 nests, from the previous summer.)
• SecondaryIlta-Sanomat (citing Syke)Merimetsojen pesimäkanta kasvoi Suomessa 14 prosenttia viime kesästä, kertoo Suomen ympäristökeskus Syke. (The cormorant breeding population in Finland grew 14% from last summer, according to the Finnish Environment Institute Syke.)
• SecondaryPEER (Partnership for European Environmental Research) — 'Finland's cormorant population at previous summer's level'This means that the cormorant population in Finland's marine areas only grew by one per cent, or a little over 200 nests, from the previous year. (Cormorant population in Finland's marine areas essentially unchanged, +1%, ~200 nests, from the previous year — consistent with the summer 2025 count of ~31,910 nests.)
• SecondaryEuropean Parliament EPRS briefing — 'Impact of cormorant predation on EU fisheries and aquaculture'The great cormorant is a highly mobile, fish-eating bird that has a significant and widespread impact on fish stocks and aquaculture sites. The highest increases were in Sweden (74 767 breeding pairs in 2023, an 83% increase compared to 2012) and Estonia (43 600 breeding pairs in 2023...).