Rescue of a Bryde's WhaleBalaenoptera edenientrapped in the Manning River, New South Wales: unmitigated success or unwarranted intervention?

Abstract

In August 1994 a Bryde's Whale Balaenoptera edeni entered and became entrapped in the Manning River, New South Wales. The individual was an immature male of the rare pygmy form of Bryde's Whale: it was 10.3 m long and weighed approximately 7.7 tonnes. The whale remained in the river for 100 days, during which time observations were made of its movements, diving habits, feeding behaviour and body condition. Apart from the risk of stranding, the entrapped whale also faced the potential threats of starvation, entanglement in fishing nets, collision with boat traffic, and exposure to low salinity and high acidity. In view of these threats, a rescue bid was launched to return the whale to the ocean. Five rescue attempts were made the last culminated in the whale being successfully towed to sea and released several kilometers offshore. Despite its emaciated condition the whale was rescued from the river before the onset of ill health or irreparable physiological damage. The whale swam away strongly on release, ...