DISTRIBUTION OF SEABIRDS IN COASTAL WATERS OFF OTAGO, NEW-ZEALAND

The occurrence, abundance, and distribution of seabirds was studied in a physically dynamic region off the coast of Otago, New Zealand. Elev en line-transect surveys were conducted in late summer and autumn of 1 994-96, when surface swarms of ''krill'', Nyctiphanes australis, were present in the study area. Twenty species of seabird were recorded. Th e abundance and occurrence of species varied between sitting and flyin g counts. The most numerous species were sooty shearwaters (Puffinus g riseus), red-billed gulls (Larus novaehollandiae), black-billed gulls (L. bulleri), and black-backed gulls (L. dominicanus). Most species we re recorded throughout the study area, and different species were comm only observed together. Spatial similarity matrices revealed strongest association between red- and black-billed gulls and black-backed gull s. The small (kilometre) scale distribution of seabirds varied between surveys, between transects, and between repeated runs of the same tra nsect 1-3 h apart. Correlations between seabird abundance, salinity gr adient, and krill density were weak. Counts of seabirds were highly po sitively skewed. This skewness, together with spatial and temporal var iability in the distribution of flocks, would make abundance estimatio n at sea difficult.