Climate change and fishing are pulling the functional diversity of the world's largest marine fisheries to opposite extremes

Abstract

Aim: Marine biodiversity is increasingly threatened by overfishing and climate change, but it is still unclear how these drivers have shaped the functional diversity (FD) of marine fish. Here, we explore how the FD of commercial marine fish communities responds to climate change and fishing pressure.Major taxa studied: Marine fish.Location: China Seas.

Implications for functional diversity conservation of China’s marine fisheries

“…biodiversity loss continues at regional and global scales in diverse ecosystems (Vitousek et al, 1997;Cardinale et al, 2006;Maclean and Wilson, 2011;Worm and Tittensor, 2011;Mouillot et al, 2013). As a critical part of biodiversity, functional diversity indices have been increasingly applied to fish communities to explore the connection between biodiversity and ecosystem function, indicate the community structure changes, and assess the effect of multiple pressures (Villeǵer et al, 2010;Mouillot et al, 2013;Stuart-Smith et al, 2013;Belley and Snelgrove, 2016;Villeǵer et al, 2017;Rolim et al, 2022;Zhao et al, 2022). However, only a few studies so far report the functional diversity of marine fish communities.…”

“…Thus, China's sustainable marine capture fishery industry is critical to the global seafood supply, food security, and seafood trade (Smith et al, 2010;Blomeyer et al, 2012;Su et al, 2020). Zhao et al (2022) recently used China's reported marine catch data and a comprehensive set of functional traits to explore how the functional diversity of commercial fish communities responds to climate change and changes in fishing pressure. They showed that climate warming and fishing significantly and oppositely affect the functional diversity (i.e.,FEve and FDiv), partly causing functional diversity fluctuations in China's seas.…”

“…Along with the development of Chinese sustainable capture fisheries and increasing climate change in recent decades, an enhanced understanding of how biodiversity changes in space and time could improve decision-making about establishing protected areas, sustainable fishery management, etc. Here, China's marine catch data and functional traits reported by Zhao et al (2022) were used to explore the temporal characteristics of functional diversity changes in fish communities caught by each province and the patterns of species' contributions to the functional space. This study could help guide targeted biodiversity conservation policies and marine fishery management under multiple pressures across various provinces and seas.…”

“…Although the catch data for Chinese fisheries have been a subject of scrutiny for many years, the main concern is that China may over-report its catch (Watson and Pauly, 2001;Pauly et al, 2014;Pauly and Zeller, 2016). However, scaling up or down the reported catch should not introduce bias into FEve and FDiv estimation (Zhao et al, 2022), and we used relative catch data to calculate them.…”

“…In general, China's marine fishing practices have been exhaustive and largely nonselective, with minimal discard over the past decades (Costello et al, 2016;Costello, 2017;Szuwalski et al, 2017;Zhang et al, 2020;Zhao et al, 2021). Moreover, the proportions of China's annual catch from different fishing methods remained relatively stable from 1989 to 2018, suggesting that no single fishing method changed disproportionately in catch over the past three decades (Zhao et al, 2022). Thus, relative catch could represent a good proxy for the compositional community changes occurring in the ocean.…”