Exploitable carrying capacity and potential biomass yield of sectors in the East China Sea, Yellow Sea, and East Sea/Sea of Japan large marine ecosystems

Liu

et al. 2022

Front. Mar. Sci.

China has become the largest contributor to marine fisheries in the world with its fishing fleets explosively increasing their fishing effort and resulting catch, but its fishery composition and sustainability have deteriorated. Limited information on fishery exploitation status encumbers effective resource management. In this study, a data-poor Monte Carlo method, the Catch-Maximum Sustainable Yield (CMSY) method, was used to estimate the historical exploited dynamics and current stock status of ten Chinese economic marine fish stocks, including Trichiurus lepturus, Larimichthys crocea, Larimichthys polyactis, Thamnaconus modestus, Scomberomorus niphonius, Ilisha elongate, Decapterus maruadsi, Scomber japonicus, Engraulis japonicus, and Clupea pallasii, which accounted for about 50% of total fish catches in the coastal waters of China and covered five functional groups (i.e., large, medium benthopelagic, large, medium, and small pelagic). Species L. crocea and L. polyactis had been subjected to overfishing since the 1950s. The others showed a decreasing trend in biomass along with the explosively increasing fishing efforts since the 1990s. Benthopelagic fish experienced overfishing pressure about a decade earlier than pelagic species. All the fish stocks investigated in this study were depleted (current biomass lower than the biomass capable of producing maximum sustainable yields, i.e., B < Bmsy) in 2019, and most species were still facing high-fishing pressure (current fishing mortality higher than the mortality capable of producing maximum sustainable yields, i.e., F > Fmsy). Also, a Schaefer model was used to assess stocks rebuilding status until 2030 under four exploitation scenarios, i.e., fishing mortality equals 0.5, 0.6, 0.8, or 0.95 times Fmsy. Most species stocks will likely recover to the Bmsy, which indicates that reduction of fishing pressure is probably the most effective way for fishery recovery.

Section: Fisheries Current Exploitation Statussupporting

confidence: 92%

Fishery Dynamics, Status, and Rebuilding Based on Catch-Only Data in Coastal Waters of China

Liu

et al. 2022

Front. Mar. Sci.

“…In recent years, the dramatic decrease in coastal fish resources and significant changes in catch composition in China caused by continuously increasing fishing pressure have attracted a lot of concerns [12,41,42]. For instance, a drastic decline was reported in CPUE in 2011 down to 0.86% of 1959 in the Bohai Sea [12,43] and to 53% of 1991 in the Yellow Sea and the East China Sea in 2000 [44].…”

Section: Discussionmentioning

confidence: 99%

Sustainable Exploitation of Dominant Fishes in the Largest Estuary in Southeastern China

et al. 2020

Water

Globally, marine fisheries have declined under multiple stresses including overfishing, climate change, and habitat degradation. The Min River Estuary, as the largest estuary in southeastern China, has confronted this situation over recent decades. In this study, the dominant species of fish stocks in the Min River Estuary, including Coilia mystus, Cynoglossus abbreviates, Collichthys lucidus, Amblychaeturichthys hexanema, Polydactylus sextarius, Harpodon nehereus, and Secutor ruconius, were evaluated by the length-based Bayesian biomass estimator method (LBB). Outcomes could be grouped into three categories as healthy, showing the lowest exploitation rate (E: 0.31–0.43) and highest relative biomass (B/Bmsy: 1.30–1.90), including S. ruconius, C. mystus, and H. nehereus; overfished, with a medium E (0.50–0.58) and B/Bmsy (0.68–0.79), including A. hexanema and C. abbreviates; and collapsed, with the highest E (0.89–0.92) and lowest B/Bmsy (0.03–0.21), including C. lucidus and P. sextarius. Corresponding imperative countermeasures such as using larger-sized mesh gears and reducing fishing intensity should be deployed according to the current status of each species for sustainable fishery exploitation and fish conservation.

“… 1956–2019 Medium 0.53–1.20 b 0.4–0.8 0.01–0.4 c Larimichthys polyactis 1956–2019 Medium 0.37–0.85 b 0.01–0.4 d 0.2–0.6 c Sardinops sagax 1989–2019 Medium 0.36–0.82 b 0.4–0.8 0.01–0.4 e Portunus trituberculatus 1987–2019 High 0.79–1.79 b 0.4–0.8 0.2–0.6 e Cuttlefishes 1989–2019 Medium 0.2–0.8 0.4–0.8 0.01–0.4 e a Referred from Zhang et al . 20 ; b referred from Fishbase ( www.fishbase.org ); c referred from Zhai and Pauly 21 ; d referred from Zhuang 22 ; e referred from Martell and Froese 23 . …”

Section: Methodsmentioning

confidence: 99%

“… a Referred from Zhang et al . 20 ; b referred from Fishbase ( www.fishbase.org ); c referred from Zhai and Pauly 21 ; d referred from Zhuang 22 ; e referred from Martell and Froese 23 . …”

Section: Methodsmentioning

confidence: 99%

Species traits determined different responses to “zero-growth” policy in China’s marine fisheries

Kang

Liu

2022

Sci Rep

China remains the largest nation of marine capture fisheries in the world in the last few decades, at the cost of offshore fisheries degradation by overfishing. Although fisheries regulations have become gradually tightened, the recovering evidences are weak and the catch species compositions are far from satisfactory. To explore better and reasonable countermeasures, besides the “zero growth” policy (i.e. the national total fisheries production limitation), five targets with different ecological traits were selected for stock assessment and rebuilding by Monte Carlo Catch-Maximum Sustainable Yield method. The results showed the control of total rather than species catch could not lead to the recovery of fisheries and maintain community function. Individual species showed different responses to overfishing according to their biological characteristics. High trophic level species can be sensitive to overfishing, and difficult to rebuild stocks after collapse. Pelagic small fish resources increased first but eventually decreased under high fishing pressure. Scientific-based restocking can enhance resource recovery. Besides “zero growth” policy, fisheries management should be further refined, in particular for main economic species based on their biological traits, as well as the support of reliable fisheries statistics and regulation implementation in place. To relieve the conflict between rising fishery products demand and falling catches, aquaculture and seeking resources from the high seas and EEZs are supposed to be successful ways, on the premise of taking full account of ecological health, maritime safety, and food security.