following recruitment event. In Þshes with this type of
dynamic, the main determinants of local population size
will be the same as for sessile organisms such as barnacles
or corals; namely, (1) large-scale factors contributing to
the number of larvae that come in contact with the patch,
(2) local factors which a¤ect the number of larvae that
settle, and (3) subsequent schedules of local post-settlement
mortality (e.g. Bertness et al. 1992).
Post-recruitment immigration in the Þshes studied
a¤ected the patterns of density established by larval recruitment
in two important ways. Firstly, immigration
occurred throughout the year and was not restricted to
the summer reproductive season. Secondly, the small scale
of movement of post-recruits (tens to hundreds of metres)
meant that immigration occurred independently at di¤erent
bommies within the same coral reef (Fig. 2). These
characteristics mean that modelling local populations affected
by post-recruit immigration will be more di¦cult
than modelling populations mainly a¤ected by the recruitment
of larvae, because inputs of post-recruits are frequent
but temporally stochastic, as opposed to infrequent
and temporally predictable for larvae.