June/July 2008

Unfortunately, only two boat surveys were carried out between 16 June and 5 July 2008, due to engine problems with the survey vessel. Both survey routes travelled north along a 28-km stretch of coast from Flamingos towards Namibe. A single pod of approximately 40 bottlenose dolphins was sighted during the second survey (Figure 1), and some photo-identification and acoustic work was carried out. A total of 24 distinctive bottlenose dolphins were photo-identified during the survey and a photo-identification catalogue for this species has now been developed (Download Here).

Shore-based survey work comprised both watches from fixed vantage points and surveys of the coast using a 4x4 vehicle. Six watches from fixed sites were carried out, comprising total effort of 22 hr 50 min. Coastal surveys using a 4x4 vehicle were carried out on 16 dates with a total of 111 hr data collected. Of the 111 hr survey effort, 50 hr 43 min (46%) was spent in search mode and 60 hr 17 min (54%) was spent in cetacean encounter mode primarily with humpback dolphins.

A total of 53 sightings and a minimum of 466 individual cetaceans were recorded off Flamingos between 16 June and 5 July 2008 (Table 1). All sightings were made from shore, with the exception of a single group of bottlenose dolphins recorded during a boat survey on 19 June.

Table 1. Summary of cetacean sightings recorded off Flamingos during June/July 2008

Species	No of sightings	No. of animals
Atlantic humpback dolphin	24	117
Bottlenose dolphin	19	326
Unidentified dolphin sp.	1	10
Humpback whale	9	13

In contrast to the January (summer) survey, no Bryde’s whales were recorded off Flamingos during June/July (winter). However, sightings of humpback whales and bottlenose dolphins were more numerous during the winter than during the summer.

Fewer Atlantic humpback dolphin sightings were recorded during the winter (N=24) than during the summer survey (N=48). However, this may be at least partly explainable by the change in survey methodology, since during the winter survey the search effort ceased as soon as humpback dolphins were located and the animal/group was then followed from shore for periods of up to 7 hr.

Due to the lack of a survey vessel, images of humpback dolphins could only be taken from shore during the June/July survey which restricted the proximity to the animals and consequently the image quality. Photo-identification was carried out during 16 of the 24 humpback dolphin sightings during the survey. Only one new animal was identified during the June/July survey, a new calf (FL10) born to animal FL3.

A total of 58 hr 48 min of focal follow behavioural data was collected during 16 humpback dolphin encounters. The majority of their time was spent either foraging (48%) or travelling (48%) along the coast. Smaller amounts of time were spent in active feeding (when the chasing and capture of fish was seen) (2%) and play/social behaviour (1%). No rest behaviour was observed. For 1% of focal follow time, the behaviour of the animals could not be determined. No acoustic data was collected on humpback dolphins during June/July 2008, due to the lack of a boat.