What hypothesis explains the impact of El Nino on fishery collapse in Peru?

The match-mismatch hypothesis provides a compelling explanation for the relationship between the El Niño phenomenon and fishery collapses, particularly in the context of Peru's fisheries. This hypothesis posits that the availability of food for fish populations and their spawning cycles are tightly interlinked with environmental conditions, including temperature and nutrient availability in the ocean.

During an El Niño event, sea temperatures rise and alter oceanic currents, which can disrupt the timing of phytoplankton blooms— the primary food source for many fish species. If the spawning of fish occurs when there is an abundance of food (a "match"), the fish population tends to thrive. However, during El Niño, if the phytoplankton blooms do not coincide with the spawning of fish due to the changed conditions, there may be a "mismatch," leading to poor survival rates of juvenile fish. As a result, this disruption can lead to a collapse in fish stocks, adversely affecting fishing industries and local economies reliant on these fisheries.

This hypothesis highlights the critical interplay between biological timing and environmental conditions, making it crucial for understanding fisheries management and conservation efforts, especially in the face of climate variations like El Niño.