Body size scaling of space use in coastal pike (Esox lucius) in brackish lagoons of the southern Baltic Sea

Combining biotelemetry and genetics provides complementary insights relevant to the management and conservation of a freshwater predator (Esox lucius) living in brackish lagoons

“…A2). These findings align with earlier research indicating that pike activity peaks during spawning due to migration to spawning grounds (Cook and Bergersen 1988;Skov et al 2018), a behavior also observed in brackish water pike populations (Tibblin et al 2016;Flink et al 2023;Dhellemmes et al 2023b). The observed increased mobility level is likely due to migrations of anadromous pike to freshwater (Tibblin et al 2015;Roser et al 2023), but is also due to movements by brackish-water-adapted individuals to their specific spawning sites (Jacobsen et al 2017).…”

“…The limited movement-based ecological connectivity observed within the study area was in line with earlier studies that have described pike as a rather sedentary species (Diana et al 1977;Cook and Bergersen 1988;Kobler et al 2008). Previous studies in our study area reported rather small core home ranges for the lagoon pike (1.5 km 2 in the lagoon system of more than 2000 km 2 ) (Dhellemmes et al 2023b), with maximal distances among two farthest recorded positions for an individual being on average 11.7 km, with most individuals having low maximal dispersal and only very few being explorers (Dhellemmes et al 2023c). Marc-recapture studies on pike in the Baltic showed even smaller dispersal range, with recapture distances of 10 km being exceptional (Karås and Lehtonen 1993).…”

“…However, pike is classically described as a sedentary, phytophilic ambush predator that has a rather small home range outside spawning time (Diana et al 1977;Kobler et al 2008;Craig 2008), although some studies in freshwater lakes showed that some individuals can be quite mobile and utilize all available habitats (Haugen et al 2006). In the Baltic Sea, mark-recapture (Karås and Lehtonen 1993) and acoustic telemetry (Jacobsen et al 2017;Flink et al 2023;Dhellemmes et al 2023b) studies showed relatively stationary behavior and rather small home ranges in coastal pike. However, during the spawning period, which usually takes place from March to May depending on latitude, Baltic pike exhibit increased mobility as they seek to reach the spawning grounds either in freshwater rivers (Tibblin et al 2016) or in brackish lagoons (Flink et al 2023).…”

Corroborating otolith age using oxygen isotopes and comparing outcomes to scale age: Consequences for estimation of growth and reference points in northern pike (Esox lucius)

“…We found no indication of movement across salinity gradients in δ 18 O Otolith patterns, although this might be due to the relatively low difference of ~1‰ between lagoon and tributary being outweighed by a strong seasonal difference. Further, pike in our system were relatively stationary (mean size of extended home range: 6.58 km ± 5.77 km; Dhellemmes et al, 2023). Movement between freshwater and tributaries was relatively rare (6%; Möller et al, 2019) and usually only for short periods of less than 14 days (Arlinghaus et al, 2023a), which was likely too short to cause a shift in δ 18 O Otolith values.…”

Combining movement ecology and genetics to understand the ecology and evolution of a freshwater top predator (northern pike, Esox lucius) that has colonized brackish lagoons in the southern Baltic Sea: implications for management and conservation of weakly connected metapopulations

“…However, pike is a classically described as a sedentary ambush predator that has a rather small home range outside spawning time (Diana et al 1977;Kobler et al 2008;Craig 2008), although some studies in freshwater lakes showed that some individuals can be quite mobile and utilize all available habitats (Haugen et al 2006). In the Baltic Sea, mark-recapture (Karås and Lehtonen 1993) and acoustic telemetry (Flink et al 2023;Dhellemmes et al 2023b) studies showed relatively stationary behaviour and rather small home ranges in coastal pike. However, during the spawning period, which usually takes place from March to May, Baltic pike exhibit increased mobility as they seek to reach the spawning grounds either in freshwater tributaries (Tibblin et al 2016) or in brackish lagoons (Flink et al 2023).…”