Considering the role of upwelling in marine ecosystems, how might a significant decrease in upwelling zones due to climate change impact the global food chain?

Question

1)It would enhance the growth of anchoveta, as they would adapt to the changing nutrient availability
2)It would have no significant impact, as marine ecosystems are resilient to changes in nutrient distribution
3)It would lead to an increase in the population of marine mammals, as they would have more food available.
4)It would likely result in a decline in phytoplankton populations, the energy base for higher trophic levels

Answer 1

The most accurate answer regarding the impact of a significant decrease in upwelling zones due to climate change on the global food chain is:

4) It would likely result in a decline in phytoplankton populations, the energy base for higher trophic levels.

Upwelling zones are critical for marine ecosystems as they bring nutrient-rich water from the deep sea to the surface, which supports the growth of phytoplankton. Phytoplankton is the primary producer in marine food webs, and a decline in their populations would significantly affect all higher trophic levels, including zooplankton, fish, marine mammals, and even seabirds. The reduction of phytoplankton would disrupt the entire marine food chain and could lead to decreased fish populations and biodiversity, ultimately impacting global food security.