Threat ranking for Asian river dolphins

The table of threats presented here draws from an extensive literature review, and from a 2017 consultative workshop and process for the development of  WWF’s Global River Dolphin Strategy. This process involved WWF experts in river dolphin range countries, as well as experts from the IUCN Cetacean Specialist Group, Yayasan Konservasi RASi (Indonesia), the Chinese Academy of Sciences,  Omacha Foundation, and the Mamiraua Institute for Sustainable Development, Brazil.  Following the identification of threats, experts* were consulted to rank them from 0 to 5, where 0 indicated the absence of the threat for that species in that country, 1= occasionally a threat, 2=currently a low level of threat with isolated incidences, 3=becoming more frequent with potential for river dolphin population impact if not controlled, 4= serious threat to the population, and 5 = presents the most severe threat to the population.

 

THREAT RANKING Irrawaddy, Cambodia Irrawaddy dolphin (Pesut), Indonesia Irrawaddy dolphin, 
Myanmar
Ganges dolphin (Susu),
India 
Ganges dolphin, Nepal Ganges dolphin, Bangladesh Indus dolphin, Pakistan (Bhutan) Indus dolphin, India Finless porpoise,
China
0-5, where 0= no threat and 5 =most severe Orcaella brevirostris Orcaella brevirostris Orcaella brevirostris

Data gathering impacted by current challenges in Myanmar

Platanista gangetica gangetica Platanista gangetica gangetica Platanista gangetica gangetica Platanista gangetica minor Platanista gangetica minor Neophocaena  asiaeorientalis asiaeorientalis
Direct threats 
Deliberate killing/hunting 0 0 3 0 3 0 0 0
Fisheries/bycatch 5 5 4 5 5 5 0 5
Illegal fishing activities (dynamite, poisoning, electrofishing) 5 (electrofishing only) 5 1 5 4 (illegal and poison fishing only) 5 1 5
Vessel strikes 1 2 2 0 2 0 0 3
Irrigation canals/pool entrapment (particularly in low flow season) 1 1 3 4 1 5 2 3
Loss of genetic diversity 4 2 2 5 Unknown 3 5 3
Decline of prey species Unknown 4 1 Unknown 3 3 3 5
Contamination due to (legal/ illegal) mining 0 0 1 0 TBC 0 0 0
Poisoning due to industrial/agricultural effluents 0 2 (palm oil) 4 1 3 3 2 2
Indirect threats
Fragmentation or reducing flows from dams/barrages 5 0 5 5 5 5 4 4
Underwater noises (e.g. vessels, mining) 0 3 4 1 2 2 1 4
Sand mining 0 0 2 2 2 2 1 4
Coal, oil or gold mining 0 3 0 1 0 0
Agriculture pollution 1 4 (palm oil) 2 3 1 4 4 4
Industrial pollution 0 0 4 2 3 3 4 3
Domestic waste 1 2 1 1 0 3 4 3
Land Use changes/deforestation increasing silt 2 3 4 3 1 4 4 2
Tourism activities (disturbance to the habitat etc) 1 0 1 0 0 0 0 1
Hurdles in achieving conservation outcomes
Weak legislative framework 0 3 2 5 0 4 2 3
Poor coordination between functionaries 0 2 3 5 2 3 3 4
Inadequate capacity 3 3 3 2 4 4 3 4
Absence of protected areas 0 0 3 5 2 1 1 1
Ineffective protected area management 0 1 4 5 4 2 2 4
Socio-economic challenges in communities 3 4 2 5 5 4 2 3
Lack of awareness 3 4 3 4 4 2 4
No government action plan  0 2 0 5 1 4 2 0

 

Threat ranking for South American river dolphins

River dolphins in the Amazon occur in a large area, encompassing six countries and three major river basins. The level/intensity of threats vary between countries and river basins, but to-date an analysis of threats hasn’t been carried out at the country and river basin level – a potential future task being discussed within the region. The threat ranking table presented below is therefore an overall South America view that summarises these threats at the species level; ranked 0-5: 0 = not a threat, and 5 being most severe.

 

 THREAT RANKING Amazon river dolphin Tucuxi
Direct threats    
Deliberate killing/hunting 4 3
Fisheries/bycatch 4 4
Illegal fishing activities (dynamite, poisoning, electrofishing) 2 2
Vessel strikes 1 1
Loss of genetic diversity 3 1
Decline of prey species 3 3
Poisoning with mercury/ arsenic contamination due to (legal/ illegal) mining 4 4
Poisoning due to industrial effluents 1 1
Indirect threats    
Dams/barrages (fragmentation, reducing flows, water diversion) 4 3
Sand mining 1 1
Coal, oil or gold mining 4 4
Agriculture pollution 1 1
Industrial pollution 1 1
Domestic waste 1 1
Land Use changes/deforestation increasing silt 4 4
Tourism 1 1