WWF survey of the entire range of the Indus River dolphin - 2001

Gill Braulik

doi:10.15468/hbnhha

WWF survey of the entire range of the Indus River dolphin - 2001

Citation

Braulik, G. 2012. WWF survey of the entire range of the Indus River dolphin - 2001. Data downloaded from OBIS-SEAMAP (http://seamap.env.duke.edu/dataset/848) on yyyy-mm-dd. https://doi.org/10.15468/hbnhha accessed via GBIF.org on 2024-12-13.

Description

Original provider: Gill Braulik, WWF-Pakistan Dataset credits: Gill Braulik, WWF-Pakistan Abstract: A survey was conducted in March and April 2001, to assess the status of the Indus River dolphin, Platanista gangetica minor, throughout its present range. A total of 1535 km of survey effort was conducted, consisting of 1375 km of the Indus River main channel, 136 km of Indus River secondary channels, and 24 km of the Panjnad River, a tributary of the Indus. The effective range of the Indus dolphin has declined by 80% since 1870. The sum of best group size estimates produced an abundance estimate of 965 dolphins. Extrapolation of encounter rates to unsurveyed channels and application of a correction factor to account for missed dolphins indicates that the metapopulation may number approximately 1,200 individuals. Dolphins occur in five subpopulations separated by irrigation barrages. A pronounced increase in dolphin abundance and encounter rate was observed in each subsequent downstream subpopulation (except the last). The three largest subpopulations were between Chashma and Taunsa. Barrages (84 dolphins; 0.28/km), Taunsa and Guddu Barrages (259 dolphins; 0.74/km) and Guddu and Sukkur Barrages (602 dolphins; 3.60/km). Reasons suggested for the high encounter rate between Guddu and Sukkur Barrages, include high carrying capacity, low levels of anthropogenic threat, effective conservation, and augmentation of the subpopulation by downstream migration of dolphins from upstream. Purpose: Status Assessment Supplemental information: Data contains information on both the detection location, which is the location of the boat when a dolphin was sighted, and also an exact location, which was the position of the boat when the dolphins were perpendicular. Exact locations were plotted but detection location was used if an exact location was not available. BHL are best, high, low estimates of group size. Best estimates were used for the observed count. Actual survey tracks followed the winding pattern of the Indus River. Tracks presented here are very approximate straight-line visual representations of the actual track. These visually indicate which river sections were surveyed but should not be used for any analysis.

Purpose

Status Assessment

Sampling Description

Study Extent

NA

Sampling

NA

Method steps

NA

Additional info

marine, harvested by iOBIS

Taxonomic Coverages

Scientific names are based on the Integrated Taxonomic Information System (ITIS).

Platanista minor
common name: Indus River Dolphin rank: species

Geographic Coverages

Pakistan,Indus River

Bibliographic Citations

Contacts

Gill Braulik
originator
position: Primary contact
WWF-Pakistan
email: gillbraulik@downstream.vg

OBIS-SEAMAP
metadata author
Marine Geospatial Ecology Lab, Duke University
A328 LSRC building
Durham
27708
NC
US
email: seamap-contact@duke.edu
homepage: http://seamap.env.duke.edu

OBIS-SEAMAP
distributor
Marine Geospatial Ecology Lab, Duke University
A328 LSRC building
Durham
27708
NC
US
email: seamap-contact@duke.edu
homepage: http://seamap.env.duke.edu

Gill Braulik
owner
position: Primary contact
WWF-Pakistan
email: gillbraulik@downstream.vg

Gill Braulik
administrative point of contact
position: Primary contact
WWF-Pakistan
email: gillbraulik@downstream.vg