Its not complicated.
"The fish are a key food for African penguins. Changes in the temperature and salinity off the west coast of Africa have made the fishes’ spawning less successful. Levels of fishing, however, have remained high in the region."
the Guardian
60,000 African penguins starved to death after sardine numbers collapsed – study
Climate crisis and overfishing contributed to loss of 95% of penguins in two breeding colonies in South Africa, research finds
