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Indus River dolphins in Pakistan © Gill Braulik Gill Braulik is is working on two projects in Pakistan, focusing on the Indus River dolphin. Location: - Indus River, Pakistan Species: - Indus River dolphin Researcher: - Gill Braulik The Indus (Platanista gangetica minor) and Ganges (Platanista gangetica gangetica) river dolphins occur only in freshwater in the separate Indus and Ganges-Brahmaputra river systems in South Asia. Both subspecies are listed as ‘Endangered’ by the World Conservation Union (Braulik et al., 2004; Smith et al., 2004), and they are among the world’s most endangered dolphins. Both river dolphin populations are severely fragmented by dams and barrages, have suffered enormous (50-80%) range declines in the last hundred years and are threatened by declining freshwater supplies, pollution, capture in fishing nets and hunting. The subspecies are the only members of the Genus Platanista which is a very primitive and ancient cetacean group only distantly related to modern Delphinids. Background to the project Despite their relatively high profile as endangered dolphins very little is known about these animals and there is confusion and uncertainty about their taxonomy. On the basis of very little morphological information the accepted classification of these river dolphins has changed multiple times from subspecies to separate species and back again. The reclassification in 1998 of the two dolphin populations from species to subspecies has caused confusion in south Asia where the dolphins occur, has reduced the perceived importance of the Indus dolphin inside Pakistan and may have negatively impacted conservation efforts by lowering their priority for allocation of international funds. At the ‘Workshop on the Shortcomings of Cetacean Taxonomy in Relation to Needs of Conservation and Management’ held in 2004 clarification of the taxonomy The team on board the survey boat on the Indus River. of Platanista was listed as high priority by this expert group because the two putative species are severely threatened and occur in only one or a few countries “Improved clarity with regard to their systematics will have important implications for their conservation and management” (Reeves et al., 2004). Improved clarity with regard to their systematics will have important implications for their conservation and management. © Albert Reichert History of the River systems The Indus River dolphin is thought to be highly endangered. The Indus and Ganges-Brahmaputra River systems have existed for at least 40 million years and evidence suggests they have been largely separate for at least five million years. Although the Indus and Ganges are ancient rivers, historically rivers near the Indus-Ganges drainage divide have been captured repeatedly and it is possible that there was faunal exchange between river systems even in relatively recent times. The fish fauna is similar between the two river systems, however there has been speciation of some catfish and carp species. The Study One of the reasons that no comprehensive study on the taxonomy of Platanista has been conducted to date is the difficulty of a collaborative study between Pakistan (home of the Indus dolphin) and India (home of the Ganges dolphin) due to the political situation in the region and problems with exporting samples to another location for analysis. With the fairly recent advent of DNA extraction from bone there is now an opportunity to use museum specimens in the west to obtain DNA for a comparative molecular study which will allow long overdue resolution regarding the relationship between these closely related populations. Samples will be taken from Indus and Ganges dolphin skeletons stored in natural history museums in the UK, USA, Germany and Pakistan and DNA extraction, sequencing and analysis will be conducted at the Molecular Ecology Laboratory at the University of Durham which has facilities for extraction of ancient DNA. Unique haplotypes, variable sites and the number of base-pair differences will be identified and compared between populations and statistical analyses conducted on the data to determine whether there are sufficient differences between populations to classify them as separate species. 1 © Gill Braulik water sources particularly the Indus River. Available water per capita is plummeting and is approaching 1000 cubic meters per person down from 5600 cubic meters per capita in 1947. The country is entering a water crisis and as its greatest source of freshwater is the Indus River system there are numerous plans to further exploit the River by constructing dams and increasing water diversion with little consideration of the environmental and social impacts this may cause. The problem is further exacerbated by climate change; reduced glacial cover and weakening monsoon rains in northern Pakistan are predicted to dramatically reduce Indus River discharge within 50 years. Declining river flows have been highlighted as perhaps the greatest threat to the long-term survival of the Indus River dolphin (IWC., 2001). Survey boat with the Guddu Barrage in the background. The proliferation of river dams are damaging the long-term survival prospects of all river dolphin species. Location: - Indus River, Pakistan Species: - Indus River dolphin Researcher: - Gill Braulik The Indus River dolphin (Platanista gangetica minor) is one of the world’s most threatened cetaceans. It occurs only in freshwater, in the mainstem of the Indus River and it is endemic to Pakistan. Dolphins are found in primarily 3 subpopulations separated by irrigation barrages (low, gated-dams). The populations are estimated as 602 (Guddu-Sukkur), 258 (Taunsa-Guddu barrages) and 84 (Chashma-Taunsa barrages) individuals. The metapopulation was estimated to number approximately 1200 animals in 2001 (Braulik, 2006). Background to the project © Albert Reichert The Indus is a highly managed river and during the dry season all of its flow is diverted for irrigation and municipal uses. For several months of the year largescale water extraction causes the river downstream of Hyderabad to be completely dewatered (i.e. dry) before reaching its delta. This large-scale and increasing diversion of water from the Indus River has severally reduced the quantity of dolphin habitat and is the primary reason for its extirpation from 80% of its former “Declining river flows have been highlighted as perhaps the greatest threat to the longterm survival of the Indus River dolphin” range. The remaining dolphins are concentrated into the only section of the Indus River that is consistently flowing throughout the year. Pakistan is one of the most water stressed countries on earth, its semi-arid climate combined with large (167 million in 2006) and rapidly expanding (2.09%) population are placing enormous and unsustainable pressure on existing Project Aims/Objectives This project aims to understand which hydrological habitat (depth and velocity) dolphins depend upon in the dry season. This information is vital to understanding the impact of decreasing river flows on dolphins, will provide valuable information for managing the dolphin population and for lobbying the government and water management authorities to maintain sufficient water in the river for a functioning ecosystem which includes dolphins. Methodology Three intensive study sites approximately 1km in length will be selected for this study. A GPS integrated depth sounder will be used to comprehensively map the depth of the site. Water velocity will be measured using a Marsh-McBirney Flo-Mate velocity meter deployed from an anchored dingy. Velocity will be measured at standard intervals in the water column on cross sections perpendicular and parallel to the river flow and a GPS position will be recorded to geo-reference each record. Data will be processed using a Geographic Information System (GIS) to create three dimensional depth and velocity maps for each study site in each flow state. The spatial distribution of dolphins within each intensive study site will be recorded over a two week period from a number of bank-based observation points. Data will be spatially analysed using GIS software and each dolphin record will be assigned a depth and velocity according to its surfacing position. Finally Generalised Linear Models will be used to examine statistically the relationship between the spatial distribution of dolphins and the hydrological variables in the study site. © WDCS Created by WDCS UK Brookfield House, 38 St Paul Street, Chippenham, SN15 1LJ T: +44 (0)1249 449500 Registered charity no: 1014705 www.wdcs.org Gill Braulik working in the field. 2 Offices in Argentina, Australia, Germany, UK and USA