Question

perus commercial anchovy industry would most likely be harmed during an el niño southern oscillation (enso) event. which of the following is the most likely explanation for the decline in anchovy during an el niño southern oscillation (enso) event? a acidic ocean waters kill off larval anchovies. b less nutrient - rich water reaches surface waters, disrupting the food web. c ocean currents move toxic contaminants from the sediments into the water column. d an increase in phosphate - based nutrients leads to an algal bloom, which would decrease available oxygen for animals like shrimp.

Explanation:

During an El Niño - Southern Oscillation (ENSO) event, the normal upwelling patterns off the coast of Peru are disrupted. Upwelling brings nutrient - rich water from the deep ocean to the surface, which supports a thriving food web. When this is disrupted, less nutrient - rich water reaches the surface, harming primary producers and the organisms that depend on them, such as anchovies. Acidic ocean waters are not the main cause related to ENSO for anchovy decline. Toxic contaminants being moved by currents is not the most likely main factor. An increase in phosphate - based nutrients leading to algal bloom and oxygen depletion is not the typical ENSO - related cause for anchovy decline.

Answer:

B. Less nutrient - rich water reaches surface waters, disrupting the food web.