Free swim surveys were used to census the populations of
A. ocellaris in order to assess the abundance of this species and its
host anemones in the study area. This technique is very useful for
covering larger areas than line transects and it has successfully
been used to census the population of anemone fish in previous
studies (e.g. Shuman et al., 2005; Jones et al., 2008). The abundance
of A. ocellaris in one anemone and the species of anemones in an
approximately 5 m wide area were recorded at a depth of 1-11 m
by scuba diving during surveys of about 1.5-2 h, covering
40-763 m. Geographic positions were recorded by GPS at each
survey start and end point. By using surface geographical coordinates,
the length of each survey was estimated.