A food web in a certain ecosystem consists of seals that feed on krill, which in turn feed on phytoplankton. Extensive krill fishing reduces the krill population rapidly. What would be observed in the ecosystem as an immediate effect of this? A) The seals would decrease in number and the phytoplankton would increase in number. B) The phytoplankton would decrease rapidly, because the seals would now feed exclusively on them. C) This would have no effect on the phytoplankton population as they just need sunlight to survive. D) The seals would increase in number because the lack of krill would mean less competition for food.