Thursday February 15, 2024
PhysOrg —
A regime shift is gradually spreading through the archipelagos of the Swedish Baltic Sea coast, where shallow bays, previously dominated by pike and perch have one by one become dominated by one of their prey species, the three-spined stickleback.
Now, research shows that the ability of the pike and perch to maintain dominance over stickleback increases if there are plenty of pike and perch nearby that can help the local population withstand the stickleback intrusion. The researchers also found that the resilience of the pike and perch populations decreased with increasing predation from gray seal and great cormorant.
Populations of pike and perch have shown marked declines along the Swedish Baltic Sea coast. One of the main causes of these declines is the dramatic increase of three-spined stickleback. The stickleback is a small species of fish that reproduces quickly and shows a good appetite for the eggs and larvae of pike and perch.