A Large Pond Receives Sewage Runoff from a Cattle Feedlot

Multiple Choice

A large pond receives sewage runoff from a cattle feedlot and fertilizer runoff from surrounding fields.The runoff contains large quantities of nitrogen and phosphorus.The pond undergoes an algal bloom.The algae die off and are decomposed by bacteria, which depletes the pond's oxygen content.Fish and invertebrates begin to die.What process is the pond undergoing, and changes in what limiting factor or factors initiated the process?

A) Eutrophication; nitrogen only
B) Eutrophication; nitrogen, phosphorus, or both
C) Trophic efficiency; phosphorus only
D) Trophic efficiency; nitrogen, phosphorus, or both
E) Biogeochemical cycling; nitrogen only