report that ocean sediment cores containing an «undisturbed history of the past» have been analyzed for variations in PP over timescales that include the
Little Ice Age... they determined that during the LIA the ocean off Peru had «low PP, diatoms and fish,» but that «at the end of the LIA, this condition changed abruptly to the low subsurface oxygen, eutrophic
upwelling ecosystem that today produces more fish than any region of the world's oceans... write that «in
coastal environments, PP, diatoms and fish and their associated predators are predicted to decrease and the microbial food web to increase under global warming scenarios,» citing Ito et al..