Yingyi Chen

1 Introduction Small dams are abundant and widely distributed across mountainous regions. Hydropower, as a renewable energy source, has gained favour among many countries and investors, leading to rapid development (Dursun and Gokcol 2011; Nautiyal et al. 2011). However, its ecological consequences are well-documented.

Abstract Underwater visual perception of fish is a core technology in intelligent aquaculture systems. However, occlusion caused by overlapping fish remains a major obstacle to achieving accurate instance segmentation. Robust segmentation under such conditions requires large-scale datasets with both morphological diversity and pixel-level annotations.

1 Introduction The alpine treeline is the distribution boundary between closed forests and high mountain vegetation, and serves as a sensitive indicator of the impacts of climate change on forest ecosystems (Lu et al. 2021). Treeline trees have expanded to higher elevations in response to climate change, causing upward shifts of alpine treelines worldwide (Devi et al. 2020; He et al. 2023; Sigdel et al. 2024).