Abstract:

Background & Aims: The Indo-Pacific humpback dolphin (Sousa chinensis) has been listed as the Grade 1 National Key Protected Animal in China. As the top predator of the inshore marine food chain, S. chinensis is an indicator species of the health status of the inshore ecosystem. Due to the important ecological, scientific and cultural values, it is also used as the flagship species for marine biodiversity conservation. Since the 1990s, the studies on S. chinensis have gradually risen, and developed to a new period in recent years along with the application of 3S (RS, GPS, GIS), ecological models, and molecular biological techniques. We summarized the studies of S. chinensis from the aspects of population ecology, behavioral ecology, molecular ecology and the threats that the species faced so far, aiming to clarify the advances in the ecological studies and the contributions to conservation of S. chinensis.
Progress: Ecological information such as distribution and abundance of S. chinensis population known globally in the world has been investigated by domestic and foreign scholars using line-transect sampling and capture-mark-recapture methods. In the context of species conservation, studies on habitat selection preference, habitat quality evaluation and potential habitat prediction of S. chinensis were performed. The rules of foraging behavior and reproduction behavior of S. chinensis were preliminarily understood, and the ecological significance of other behaviors were also explored. With the application of molecular biotechnology, the genetic differentiation of S. chinensis and its vulnerability to climate change have been preliminarily revealed. Human activities such as marine construction projects, underwater noise, marine pollution, and fishery activities are still the main threats to S. chinensis.
Perspectives: Based on the summary of existing studies, we propose the following prospects for the future ecological research and conservation of S. chinensis: (1) Establish a dynamic baseline database at the national level to better track the population dynamics and habitat environment changes of S. chinensis. (2) Establish a habitat identification and conservation evaluation system, and carry out identification and hierarchical management of critical and potential habitats of S. chinensis. (3) Study the habitat selection mechanism from the ecosystem level, combined with the ecological model to explore the carrying capacity of the current habitat to the S. chinensis, and further explore the impact of habitat hydrological factors, biological resources and human activities on the habitat selection of S. chinensis. (4) Construct a genetic resource database for S. chinensis, and explore the links among natural selection, ecological impact and genetic evolution, so as to reveal the molecular mechanisms of species evolution, adaptation and endangerment. (5) In order to effectively deal with the impact of global marine environmental changes on the S. chinensis, it is recommended to establish a scientific research cooperation platform and protection management network among the S. chinensis distribution countries.

Key words: Sousa chinensis, ecology, advance, conservation