Oceanographic observations on the outer shelf and slope in the central region of the Great Barrier Reef (1980-1981)

Chemical and biological oceanographic data were collected at intervals of approximately one month, from the central region of the Great Barrier Reef between March 1980 and August 1981. The survey area covers a section of the Coral Sea off Townsville, including the Great Barrier Reef from Palm Passage in the north to Flinders Passage in the south. This research was undertaken to examine seasonal nutrient distributions and thermohaline cycles. Cruises 1 to 10 followed a pattern which incorporated 4 transects, 2 of which lay parallel to the continental margin on each side of the reef whilst the other 2 traversed the reef through Palm and Flinders Passages. Cruises 11 to 19 followed transects through Palm and Magnetic Passages. Additional transects were made during cruises 13, 15 and 18 to complete a grid pattern across the outer shelf and shelf-break.Samples were routinely taken from the following nominal depths: 0, 5, 10, 25, 50, 100, 150, 200, 300, 450, 600 and 750 m. When the depth was less than 750m, the nominal depth of the bottom sample was set to 3m above the bottom. Station 31 was selected as a fine sampling station. Here the water between 90m and 150m was sampled at 10m intervals.Parameters measured:Nutrients: Nitrate, nitrite, phosphate and silicateDissolved Oxygen SalinitySea TemperatureChlorophyll-a, Phaeopigments