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Göteborgs universitets publikationer

Primary productivity in a coastal ecosystem: a trophic perspective on a long-term time series

Författare och institution:
Peter Tiselius (Institutionen för biologi och miljövetenskap, Kristineberg); Andrea Belgrano (-); Lars Andersson (-); Odd Lindahl (Institutionen för biologi och miljövetenskap, Kristineberg)
Publicerad i:
Journal of Plankton Research, 38 ( 4 ) s. 1092-1102
Artikel, refereegranskad vetenskaplig
Sammanfattning (abstract):
To investigate forcing factors on a coastal plankton food web, primary production was measured every 2 weeks for 28 years. On a decadal scale, the North Atlantic Oscillation (NAO) correlated positively to primary production (r = 0.44, P = 0.021) and winter surface nitrate (r = 0.60, P = 0.0014) and phosphate (r = 0.66, P = 0.0003; r = 0.60, P = 0.0014). This suggests that climate forcing through increased wind and vertical mixing leads to higher entrainment of nutrients which stimulate yearly primary production. The highest production occurred in summer (1105 ± 16 mg C m−2 day−1) and correlated positively with zooplankton biomass (r = 0.61, P = 0.037), but showed no relation to phytoplankton biomass. Estimated phytoplankton grazing by copepods was low, but ciliates had the potential to remove all the phytoplankton biomass daily. Copepods, in turn, could exert a strong predation on ciliates which indicates a top-down regulation of phytoplankton biomass. Advection of copepods into the fjord and predation of jellyfish are suggested as the main regulatory factors for the copepod populations. We conclude that climate affects the pelagic ecosystem in the fjord through the NAO, but that biological interactions through grazing and predation by copepods regulate the system on a seasonal scale, indicative of a trophic cascade.
Ämne (baseras på Högskoleverkets indelning av forskningsämnen):
Biologiska vetenskaper ->
Ekologi ->
Marin ekologi
Postens nummer:
Posten skapad:
2015-12-17 16:17
Posten ändrad:
2016-09-20 12:48

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