Skinny dolphins : Can poor body condition explain population decline in Indo-Pacific humpback dolphins (Sousa chinensis)?

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Indo-Pacific humpback dolphins (IPHDs) who form resident populations along the Chinese coastline are facing a wide range of anthropogenic disturbances including intense fishing and some populations have been shown to experience a severe decline. Body condition is thought to be a good indicator of health since it is linked to survival and reproductive success. In order to better understand population trends, we investigated whether the body condition of IPHDs is poorer in populations whose status is alarming than in other populations. UAV flights were conducted from 2022 to 2023 in four locations (i.e., Sanniang Bay, Leizhou Bay, Jiangmen, and Lingding Bay) in the northern South China Sea. Body ratios were calculated using the body length and widths of IPHDs and were used to analyze differences among seasons, locations, and demographic parameters. A PCA was then used to obtain a detailed picture of the body condition composition of dolphins at each location. Results showed that dolphins from Leizhou Bay and Jiangmen were in better body condition than those from Sanniang Bay and Lingding Bay. Since populations inhabiting Sanniang Bay and Lingding Bay have been shown to experience a sharp decline, it can be hypothesized that poor body condition may have played a role in such a trend. Further investigations of the factors impacting IPHDs' body condition are needed, including monitoring of prey density, contaminant concentration, stress levels, and impacts of human activities on dolphins' behavior. In addition, the creation of a robust scoring method would allow for regular monitoring of IPHDs' body condition to inform conservation measures.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:917

Enthalten in:

The Science of the total environment - 917(2024) vom: 20. Feb., Seite 170401

Sprache:

Englisch

Beteiligte Personen:

Serres, Agathe [VerfasserIn]
Lin, Wenzhi [VerfasserIn]
Liu, Binshuai [VerfasserIn]
Chen, Shenglan [VerfasserIn]
Li, Songhai [VerfasserIn]

Links:

Volltext

Themen:

Cetacean
Diet
Foraging
Health
Journal Article
Nutritional status
Overfishing

Anmerkungen:

Date Completed 22.02.2024

Date Revised 22.02.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.scitotenv.2024.170401

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM367710285