ENSO事件对台湾三种隐性鲻鱼早期生活史时空分布与生长速率的种间差异性影响

本研究通过遗传鉴定与耳石微结构分析，结合广义加性模型（GAMs），揭示了ENSO（厄尔尼诺-南方振荡）通过调控海表温度（SST）和漂流生长率（DGR）等因子，显著影响西北太平洋三种隐性鲻鱼（NWP1–3）在台湾河口区的物种组成与早期生长格局。拉尼娜期低温促进NWP1丰度与生长，厄尔尼诺期高温利于NWP3空间扩张，而NWP2虽常年优势但生长受升温抑制。研究成果为气候变化下亚热带河口鱼类资源管理提供关键生态学依据。

　　

Section snippets

Sampling collection

juvenile grey mullets were collected from the four estuaries of Lanyang River (LY), Gongsitian River (GS), Huwei River (HW) and Baoli River (BL) in Taiwan (Fig. 1) between December to the next March during the years 2011–2012 (classified as the La Ni?a period), 2013–2014 (the normal period) and 2015–2016 (the El Ni?o period) by using set nets and hand-nets. The three sampling periods were identified based on the Oceanic Ni?o Index (ONI)(Supplementary Figure S1), an indicator of temperature

Spatial-temporal variations in species composition

In this study, the species of a total of 2127 fish juveniles were identified using DNA rapid screening. The highest abundance was observed in NWP2, accounting for 81.4?% (n?=?1731). Following this, NWP1 was the second most abundant species at 12.9?% (n?=?275), while NWP3 was the least abundant, representing only 5.7?% (n?=?121).

The composition proportions of the three cryptic mullet species were significantly different across years. Our results found that the NWP2 was the dominant species

Discussion

This study observed the impact of ENSO events on the species composition and growth rates of fish in the waters surrounding Taiwan. Although some months and estuaries lacked mullet juveniles’ samples due to sampling deficiencies, sufficient data from the TS and the BL were available to represent annual species composition. Previous studies have suggested that salinity is an important factor influencing fish growth rates (B?uf and Payan, 2001, Gaumet et al., 1995); however, this factor was not

Conclusion

This study observed significant spatio-temporal variations in the species composition of these three cryptic mullet species. These shifts are likely driven by ENSO-induced environmental changes in the waters surrounding Taiwan, which may directly or indirectly affect the spawning behavior of mature mullet, as well as the growth, mortality, and dispersal patterns of juveniles, ultimately leading to differences in species composition over time and space.

During the La Ni?a period, conditions were