Explainer: Why do thousands of seashells wash up on Karachi's shores every monsoon?

Every monsoon, thousands of seashells wash up on Karachi's beaches, a curious phenomenon explained by a combination of upwelling and marine heatwaves that stir up deep-sea organisms. Fishermen and scientists have long puzzled over this, linking it to changes in ocean currents and temperatures. This year, there are hints that 2026 might see a shift due to ongoing climate changes, potentially altering this annual spectacle. Understanding these patterns is crucial for both marine conservation and local fisheries, highlighting the broader impacts of environmental changes on coastal ecosystems.