Management of Pikeperch Migrating over Management Areas in a Baltic Archipelago Area

Abstract

Pikeperch Sander lucioperca (L.) were tagged in an area where ten small independent management units regulate fisheries, in order to analyze the relevance of migrations for the management. A total of 465 fishes were tagged in connection with the spawning migration. The number of recaptures was 96. The distribution of recaptures between areas and that of total catches, estimated from questionnaire to housholds and, individuals in the survey area, were correlated. The comparison of tagging and recapture dates showed that the same pikeperch migrated to the spawning areas at the same time in two subsequent years, indicating the existence of individual spawning behavior. A modified yield/recruit-model demonstrated that in situations where the dispersal area of a pikeperch stock overlaps with several management areas, the risk of overfishing is very high. Management of this kind of fisheries needs cooperation between units as well as sound data on the movements of pikeperch to define the effects of fishing regulations.

Management of pikeperch stocking in Lake Balaton: effect of season, area, fish size and method of release on the rate and distribution of recaptures

“…Total four years (reported) recapture rate (17.4%) was similar to the 17.5% two years recapture rate of common carp in Lake Balaton (Specziár and Turcsányi, 2014). However, wild-born, tagged pikeperch were recaptured by fishermen at a higher rate of 20.6% in a Baltic Archipelago Area (Saulamo and Thoresson, 2005) and 30.4% in Lake Mälaren, Sweden (Andersson et al, 2015). In line with our presumption, results proved that influence of pikeperch stocking on anglers captures varies between stocking seasons and stocking areas as well as it depends on the size of fish at release in Lake Balaton.…”

“…On the other hand, due to overexploitation of adults and loss of natural spawning and nursery areas reproductive success of pikeperch populations is falling and now often fails to meet ecological and economic demands (Saulamo and Thoresson, 2005;Specziár and Erős, 2016). Exposure of pikeperch recruitment to adverse human impacts is also enhanced by the high sensitivity of spawning success, and early life and first wintering survival of this species to year-to-year variations of environmental conditions (Ruuhijärvi et al, 1996;Lappalainen et al, 2009).…”

Climate Warming and Pikeperch Year-Class Catches in the Baltic Sea

“…Recoveries from tagging studies have indicated that pikeperch migrations are typically less than 20 km (Lehtonen 1983;Saulamo and Thoresson 2005). The distance between our study areas is over 300 km.…”

Effects of abiotic factors on movements of pikeperch during pre-spawning and spawning season in a Baltic archipelago

“…1). The two inner basins (Granfjä rden and Ö sthammarsfjä rden), which are the main spawning grounds for pikeperch in the area (Saulamo & Thoresson, 2005), are eutrophic and turbid with chlorophyll-a concentration about 70 mg m -3 and Secchi-depth of 0.3-1.2 m (Sandströ m & Karå s, 2002). The primary production decreases and the Secchidepth increases towards the outer archipelago being 1.8-3.5 m in Galtfjä rden (Sandströ m & Karå s, 2002).…”

“…Migrations of pikeperch (Sander lucioperca (L.)) have been studied extensively in the Baltic Sea area (Virbickas et al, 1974;Lehtonen, 1979;Lehtonen & Toivonen, 1987;Saulamo & Thoresson, 2005). Generally, pikeperch migrate between spawning, feeding and wintering areas (Lehtonen, 1979).…”