Distribution and abundance of pelagic juvenile fish around Grub Reef, central Great Barrier Reef

Two light traps were anchored at each of nine sites around Grub Reef from the 26th February to the 3rd March 1990. Deployment was timed to coincide with the period between the new and first quarter phases of the moon. Sites 1 to 3 were located on the front of the reef, while sites 4 and 5 were located in the channel through the reef. Sites 6 and 7 were located in the central lagoon and sites 8 and 9 were located at the back of the lagoon. At each site, traps were anchored on a common swing mooring, with one trap buoyed to fish 1 metre below the surface and the other buoyed to fish within a few metres of the bottom, when the bottom topography was suitable.

Each night, light traps were lit for three intervals (2100-2200, 0000-0100 and 0300-0400 AEST) to counter the unknown effects of tide and time of night on catch rates. Traps were cleared in the morning and catches preserved for later analysis. Fish were separated from the invertebrates, measured and identified to the lowest possible taxonomic resolution.