生物多様性と絶滅危惧種のジャーナル

Recent Scientific Advances on the Indus River Dolphin (Platanista minor)

Abstract

Aamir Ibrahim1, Bingyao Chen, Hassan Ali, Imran Khaliq, Carolina S. Gutstein, Sajjad Hussain, and Guang Yang*

The family Platanistidae is most basal position among the Odontoceti lineages, all members has been extinct except two the Ganges river dolphin (Platanista gangetica)and the Indus river dolphin (P. minor). Their ancestors were deep marine dwelling and moved to the freshwater ecosystem of the subcontinent and thrived in the Ganges river system, later invaded the Indus river system by following the shifting flow pattern of the tributaries. The development of dams and barrages has severe negative impact, habitat destruction; isolation and extirpation of several subpopulations, there were only few hundred individuals in Pakistan. In 1974, conservation efforts were carried out in Pakistan, now are highly appraised and available data reflects an increasing population trend across the Indus River in Pakistan. During dry season dolphins prefer to stay in deep water pools, which increase group sizes, and intraspecific interactions which can be predicted from different skin marks. These marks are promising marks for the Capture-mark-recapture (CMR) and to assess the underwater threats. The conflict between fisheries and dolphins may also reach at intense level during dry season, when predator and fisheries target the same species which may lead to injuries among adults and high mortalities among the calves (1-2 years age). There is still, a big gap on the information of any disease and on identification of the parasites at species level. Future studies should be focused on the preference prey and the prey abundance and density across the habitat. The prevalence of microplastics from the Punjab river section and the intensive use of pesticides in the agriculture bed on the immediate banks of both sides in Sindh and Punjab indicated rise in water pollution. It is necessary to monitor water quality around the year for the long term conservation of this endangered species.