In the relatively simple Baltic Sea ecosystem, zooplankton-feeding sprat
is a major food source for breeding seabirds and piscivorous fish, and an important resource for
commercial fisheries. Large-scale and long-term ecosystem changes resulting mainly from over fishing
and recruitment failure of cod
, which is the main fish predator of sprat, have
affected natural-history patterns in a piscivorous seabird, the common guillemot
, in a complex
way. As the sprat stock increased, leading to lower energy content of fish, common guillemot
chick body mass at fledging decreased. However, chick fledging body mass recovered in recent years
as the sprat stock diminished, which brought about corresponding increases in sprat weight-at-age
and energy content. The cod and sprat fishery affect the common guillemots in the Baltic Sea, but the
effects differ depending on the management strategy.
2006. Vol. 323, 233-238 p.
Cod · Baltic Sea · Fisheries management · Gadus morhua · Common guillemot · Sprat ·