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Taiwan Bank (TB) is located in the southern Taiwan Strait (TS). The uplifted continental slope and bottom currents in this area result in the formation of upwelling areas, which serve as crucial fishing grounds. Climate-induced fluctuations in fish populations occur in the TS. However, how predation and competition affect the interspecies relationships in the TB ecosystem warrants clarification. In this study, we collected high-grid-resolution data on fishery activity (2013–2019) and constructed ecosystem models using Ecopath with Ecosim (EwE). Three mass-balanced models for determining the influence of El Niño–Southern Oscillation (ENSO) events on the TB ecosystem were constructed using EwE. A range of groups, including representative pelagic, benthic, and reef species, were collected for analyzing the relationship between migratory and sedentary species in terms of ecosystem structure variation due to climate change. The results demonstrated that the total system throughput (TST) was 10,556–11,122 t km−2 year−1, with an average transfer efficiency of 12.26%. According to the keystoneness index, calculated through mixed trophic impact analysis, Polydactylus sextarius and Scomber japonicus were the key species with top–down control and relatively high impact on the ecosystem in normal years. The keystone species also shifted to the predator fish Thunnus albacares and Katsuwonus pelamis during El Niño and La Niña events, respectively. Moreover, total biomass, TST, consumption, and respiration were noted to increase during ENSO events. However, during La Niña events, the diversity and connectance indexes were relatively low but pelagic species' biomass was relatively high, whereas the biomass of most benthic and reef species was relatively high during El Niño events. [ABSTRACT FROM AUTHOR]

Context: Swimming crab is a vital fishery resource and a valuable source of income in the southern East China Sea, but it lacks management strategies, especially when using different fishing gear. Aims: This study aimed to determine the effects of spatial–temporal conditions and vessel capacity on swimming crabs by using different fishing-gear types in the Taiwan Strait (TS). Methods: We used generalised linear mixed models (GLMMs) to investigate data from Taiwanese vessels (2011–2019) on how spatial–temporal conditions and vessel capacity affected the catch of swimming crabs when using trawls, gill-nets and traps. Key results: The results showed that the traps (>80.0%) caught more swimming crabs in the TS than did the gill-nets (6.6%) and trawls (8.0%). Additionally, the GLMM analysis showed that Charybdis feriatus , Portunus pelagicus and Portunus sanguinolentus catches by traps and trawls were significantly affected by different fishing locations, climate events, work hours and vessel sizes. However, for gill-nets, spatial–temporal conditions and vessel capacity did not affect the catch of C. feriatus. Conclusions: Monitoring fishing efforts and environmental factors is vital to understanding their impacts on marine ecosystems. Implications: These findings enable future sustainable crab fishing through harvesting strategy planning, ecosystem management and spatial–temporal governance. The catch performance of fishing gear depends on species' behaviour, habitat, fishing grounds, fishing regulations and oceanographic conditions. Besides, to optimise the catch, experienced fishermen mostly use the right gear at the right time and place. Therefore, the fact that baited traps more efficiently target swimming crabs than do other gear types may be due to two critical factors, namely, the habitat of the crabs in the benthic area and the chemoreceptive sensory behaviour of crabs in detecting the bait. [ABSTRACT FROM AUTHOR]