Examining Environmental Factors Behind The Declining Occurrence of Dolphins in Hong Kong Waters Using Multivariate Statistical Methods

Abstract

The decline of Indo-Pacific humpback dolphins in Hong Kong mirrors a global issue affecting their populations. Threats like habitat degradation, pollution, and overfishing contribute to their dwindling numbers. Habitat loss due to reclamation projects disrupts their natural environment and displaces them from vital feeding and breeding grounds. This, coupled with other human-induced stressors, has led to population declines in various regions.Our study analyzes dolphin density and environmental variables from 1996 to 2020, revealing key factors influencing dolphin presence. Temperature, salinity, fish production, suspended solids, nitrogen, E. coli, seawater clarity, and high-speed ferry traffic all play significant roles. Reclamation activities, in particular, have a substantial impact on dolphin habitats and contribute to their local disappearance.Despite the establishment of marine protected areas, more comprehensive conservation measures are necessary. Preserving critical habitats and reducing human-induced stressors are vital to ensure the survival of Indo-Pacific humpback dolphins in Hong Kong and beyond.

Keywords: Dolphins, Hong Kong, occurrence decline, anthropogenic impacts, Environmental factors, Habitat use