Observations on recruitment, growth and ecology in a diverse living brachiopod community, Doubtful Sound, Fiordland, New Zealand.

Many aspects of brachiopod recruitment settlement and ecology remain unknown Ills study analysed brachiopod settlement and recruitment patterns for a diverse range of brachiopod species in shallow water mid latitude communities at five sites in Doubtful Sound, Fiordland New Zealand Recruitment plates (slate tiles) with various treatments (caged, fenced, open) to investigate the effects of predators and grazers were attached to near vertical fiord walls for periods of 12 22, and 32 months between 1993 and 1995 The thirty tiles studied were colonized by a wide range of epibionts including about 4000 individuals belonging to five species of brachiopods the rhynchonellide Notosaria nigricans and the terebratulides Liothyrella neozelanica, Calloria inconspicua Terebratella sanguinea and Neoaemula vector Our observations are consistent with annual and seasonal spawning in the species studied, taking place in late summer (February) for one species (I tothyrella) and early winter (May and June) for Notosaria Terebratella and Calloria There may be a second less intense spawning episode in spring Brachiopod recruitment was relatively high but the population structure was undercut by high mortality with few brachiopods surviving for more than 2 years Low repli cation of recruitment tiles under different conditions pre eluded the use of statistical treatments However the principal determinants of the density and species richness patterns of the brachiopods appear to relate to the length of time the tiles were deployed (for one two or three spawning cycles), and the diversity and density of brachiopod species attached to the adjacent fiord walls Water depth substratum differences and predator exclusion fictors appear less significant Growth rates of up to 5 mm/year were observed for several species.