A Young Eden's Whale (Balaenoptera edeni edeni) Wandering in a Busy International Container Port

Eden's whale (Balaenoptera edeni edeni) is one of the least-understood baleen whales, with a global distribution that is almost completely unknown; only a few basic population studies of this species have been reported thus far. On 29 June 2021, a single Eden's whale was sighted in Dapeng Bay, Shenzhen, a busy international container port. This sighting was the first record of a live Eden's whale in the area, and it attracted immediate widespread attention. Our research team monitored the whale, nicknamed "Xiaobu" by Shenzhen citizens, until its disappearance. There were 48 sightings of the whale over a period of 50 days during vessel-based surveys from 2 July to 29 August 2021. Xiaobu was mainly sighted in coastal areas with a depth of 8.70 to 16.30 m; it remained 1 km offshore. The whale moved in a small minimum convex polygon range of 44.67 km2 and kernel density estimation range of 87.96 km2. From 2 to 27 July 2021, the whale was sighted near the Liquefied Natural Gas Pier in the eastern part of Dapeng Bay; it moved toward the Yantian International Container Terminal in the western part of Dapeng Bay between 28 July and 25 August, after which it was not sighted again. Its shift from east to west may have been influenced by food distribution and/or a gradual increase in familiarity with the local environment. Aerial vertical photogrammetry estimated a short body length of 7.49 m, indicating a young whale. Based on stranding records from the Chinese coastal area, the Eden's whale population in Beibu Gulf presumably migrates northward to the East China Sea (approximately 2,000 km northeast) in April, and then returns in December. Xiaobu may have become separated from the Eden's whale group when whales reached Shenzhen during the northward migration.