A transect of nine oceanographic stations, extending from the GBR lagoon to the outer slope, was surveyed through Palm Passage (central Great Barrier Reef) in 1983, with an emphasis on the summer upwelling period. In total, 128 temperature and salinity profiles were obtained. Water samples were collected at five stations on the shelf and the outer slope (total = 100 stations) for analysis of inorganic nutrients and phytoplankton pigments.
The frequency of sampling was most intense during the late summer (January - March), with five cruises of six days duration at one to three week intervals. During these cruises, the transect was occupied very second day. For the remainder of the year, single transects were occupied at intervals of approximately two months.