Heterogenization of marine catch assemblages over the past four decades in China

Abstract Marine fishery biodiversity is crucial for sustainable food supply to billions of people, yet it has been severely damaged by a long history of overexploitation. Although local marine species diversity in response to anthropogenic change has been intensively studied, however, the trajectories of marine catch assemblages at larger temporal and spatial scales remain elusive. Here, we use data collected from the China Fishery Statistical Yearbook that spans 37 years (1983-2019) to systemically and quantitatively assess the trajectory change of marine catch assemblages and the drivers. We found that both species taxa and the structure has undergone two distinguish periods (1983-2002 versus 2003-2019), and the composition of marine catch experienced rapid temporal heterogenization for both occurrence and abundance-based dissimilarity over about past four decades, but the rate of the change has slowed in the latter two decades. Importantly, the fish species with a smaller size and living in the upper water may drive the heterogenization in the earlier two decades. Conversely, the fish with a bigger size and living in the deeper water may drive the heterogenization in the latter two decades. These findings can help to identify species that urgently need more effective fishing strategies, and incorporate them into future marine conservation and fisheries management decisions to rebuild sustainable marine fishery stocks.