On behalf of my co-authors, I would like to share you our recent publications as below, hope you are interested in this paper.
Wenzhi Lin, Ruiqiang Zheng, Binshuai Liu, Shenglan Chen, Mingli Lin, Mingming Liu, Wenhua Liu, and
Songhai Li. (2022) Low survivals and rapid demographic decline of a threatened estuarine delphinid.
Frontiers in Marine Science. 9:782680. doi: 10.3389/fmars.2022.782680.
Beibu Gulf’s (BBG) Indo-Pacific
humpback dolphins present both a genetic differentiation
and phenotypical differences from conspecifics from other areas of the South
China Sea. Given the recent urbanization and industrialization in southern China, humpback dolphins
from the BBG warrant conservation attention. However, this population’s demographic
trend is unclear, making it hard to take conservation measures. To assess the population
status of humpback dolphins in the BBG, photo-identification surveys were conducted
between 2015 and 2019 in the inshore region surrounding the Dafeng River Estuary,
which represents the most urbanized and industrialized coastal area of the BBG region.
Robust design modeling suggested a constant survival for the female adults (0.89, 95%
CI: 0.83–0.94). In comparison, the survival of the juvenile and sex-undetermined adults
dropped from 0.92 (95% CI: 0.75–0.98) in 2015 to 0.86 (95% CI: 0.71–0.94) in 2016 and
bounced back to 0.89 (95% CI: 0.80–0.94) in 2018. The low level of survival may justify the
rapid decline in the annual population size from 156 (95% CI: 133–184) in 2015 to 102
(95% CI: 98–107) in 2019. We found little impact of emigration on the dolphin
demographic process. Instead, the low and fluctuating survivals, although with
overlapping confidence intervals, seemingly suggested a presence of strong marine
stressor(s). Our study highlighted that obtaining high-resolution data is essential to
improving our understanding of the demographic dynamics. Moreover, the
anthropogenic stress in the BBG region should be quantitatively studied in both
temporal and spatial perspectives, to help depict the ecological response of the
dolphins to anthropogenic activities.
Songhai Li Ph.D. & Prof.
Marine Mammal and Marine Bioacoustics Laboratory
Institute of Deep-sea Science and Engineering
Chinese Academy of Sciences
28 Luhuitou Road, Sanya, 572000, China