An Ecosystem Inverted
For centuries, the Zhoushan Fishing Ground was called the "Chinese fish storehouse." Fed by the nutrient-rich discharge of the Yangtze River, its waters supported a massive ecosystem. The fishery's primary targets were four species: the large yellow croaker (Larimichthys crocea), the small yellow croaker (Larimichthys polyactis), the largehead hairtail (Trichiurus lepturus), and cuttlefish. In the mid-1970s, the annual catch of the large yellow croaker alone peaked at around 200,000 tons. The entire fishery was central to the regional economy, supporting a population of nearly one million people, including over 300,000 fishers.
The collapse began after the 1950s and accelerated dramatically. The introduction of motorized trawlers, bottom-trawling nets that scraped the seabed, and a massive increase in the size of the fishing fleet created unsustainable pressure. By the 1980s, the once-abundant large yellow croaker was nearly gone from the sea, its population having plummeted by over 90 percent. Today, wild-caught large yellow croakers are commercially rare, and the fishery now targets smaller, lower-value species. This process, known as "fishing down the food web," removed the top predators from the ecosystem, led to for a radical transformation.