Hot Topic: Effects of Climate Variability on Fisheries
Part B: Intermediate Variability: Anchovy Collapse
Most of the world's largest ocean fisheries are based on small fish such as anchovies and sardines. These species dominate in the highly productive upwelling regions along the coasts of California, Peru, the Canary Islands, and South Africa. These species are also common in other nutrient enriched areas such as those near Japan and Argentina. Populations of anchovies and sardines tend to expand rapidly when feeding and spawning conditions are favorable, but are susceptible to rapid collapse when ocean conditions change.
- Examine the graph below of Peruvian anchovy catches from 1950-2000.
Data for image from FAO 2001.
Answer the following questions to check your understanding of the information presented in the graph above.
- What major trends do you see in Peruvian anchovy catches between 1950 and 2000?
- What are some possible reasons for the low anchovy catches during the 1970s and 1980s?
Stop and Think
1: Given that anchovies rely on upwelling for food, how do you think El Niño events might affect the anchovy fishing industry?
2: Based on your observations in Part A of how quickly California squid have typically rebounded after El Niño events, which (if any) of the trends in Peruvian anchovy catches do you think might be due to El Niño, and which (if any) do you think are due to other influences? Explain your reasoning.
- Read this passage about The Peruvian anchovy industry and El Niño. (cotf.edu/ete/modules/elnino/crbiosphere.html)
Answer the following questions to check your understanding of the information presented in the passage about El Niño and the Peruvian anchovy industry.
- What caused the 1972 anchovy collapse?
- What were some of the consequences of the anchovy collapse?
- What other effects has El Niño had on biospheric events worldwide?