A study was aimed to determine the biological status of the Indus river dolphin, Platanista minor Owen in Indus river with respect to distribution, threats and protection throughout its range in Northern Pakistan. For...A study was aimed to determine the biological status of the Indus river dolphin, Platanista minor Owen in Indus river with respect to distribution, threats and protection throughout its range in Northern Pakistan. For this purpose, a survey was conducted in an area of 103.5 km including the Indus river and its tributaries in March 2009 for estimating its distribution and population size using both direct observations of the dolphin as well as indirect evidences from its signs. The best group size was estimated with an abundance of 54 dolphins. Approximately 53.7% （1.07 dolphin＆m） of the dolphin-population occurred in 27 km from Miran onward to Ramak, however, 38.9% （0.46 dolphin/km） occurred in 46 km from Dera Ismail （D.I.） Khan bridge to Miran, moreover, 7.4% （0.13 dolphin/kin） occurred in 30.5 km from Saggu, near Meetapur-village to D.I. Khan bridge in the Indus river. The highest density was found between Miran and Ramk. A pronounced increase in dolphin encounter rate and abundance were observed in a downstream-direction. Threats to dolphins include too much vessel-traffic, disturbance by the crane, duck-hunters, and no effective-protection. Dolphins are particularly vulnerable to the high levels of anthropogenic activities because of their restricted habitat. Threats vary geographically in their importance, but generally include accidental killing during fishing-operations, habitat-loss and population-fragmentation from water development. Deliberate killing for dolphin products also threatens the dolphins. Potential for protections and possibilities for dolphin eco-tourism measures must be taken.展开更多
文摘A study was aimed to determine the biological status of the Indus river dolphin, Platanista minor Owen in Indus river with respect to distribution, threats and protection throughout its range in Northern Pakistan. For this purpose, a survey was conducted in an area of 103.5 km including the Indus river and its tributaries in March 2009 for estimating its distribution and population size using both direct observations of the dolphin as well as indirect evidences from its signs. The best group size was estimated with an abundance of 54 dolphins. Approximately 53.7% （1.07 dolphin＆m） of the dolphin-population occurred in 27 km from Miran onward to Ramak, however, 38.9% （0.46 dolphin/km） occurred in 46 km from Dera Ismail （D.I.） Khan bridge to Miran, moreover, 7.4% （0.13 dolphin/kin） occurred in 30.5 km from Saggu, near Meetapur-village to D.I. Khan bridge in the Indus river. The highest density was found between Miran and Ramk. A pronounced increase in dolphin encounter rate and abundance were observed in a downstream-direction. Threats to dolphins include too much vessel-traffic, disturbance by the crane, duck-hunters, and no effective-protection. Dolphins are particularly vulnerable to the high levels of anthropogenic activities because of their restricted habitat. Threats vary geographically in their importance, but generally include accidental killing during fishing-operations, habitat-loss and population-fragmentation from water development. Deliberate killing for dolphin products also threatens the dolphins. Potential for protections and possibilities for dolphin eco-tourism measures must be taken.
