Authors
Adam Smith, Najeen Rula, Rachelle Brown, and Kaysha Kenney
2024
Executive Summary
The red macroalgae Asparagopsis taxiformis (Red Sea Plume) was observed at all locations during this monitoring period. Three monitoring techniques were utilised to assess reef health at three locations containing control and impact sites. Magnetic Island had an average macroalgae cover between 25% and 51.1% and Keppel Island had an average macroalgae cover of between 6% and 29.6%. The macroalgae at Magnetic Island was harvested at depths of 1 m to 3 m and in the Keppel Islands between 8 m to 12 m. It appears that there are more macroalgae at Magnetic Island compared to Keppel Islands. The average number of species observed using the iNaturalist method at Magnetic Island varied from 6 to 25 with an overall average of 18 species. The most observations were Red Sea Plume, Chinese Demoiselle and Goldstripe Butterflyfish. The average number of species observed using the iNaturalist method at Keppel Island varied from 12 to 42 with an overall average of 26 species. The species with the most observations were Longfin Rockcod, Chinese Demoiselle and Red Sea Plume. It appears that there are similar species but more species due to greater water depth, great visibility, location (i.e., further offshore) and/or less macroalgae in the Keppel region. Our interpretation is that macroalgae cover in the treatment locations at both Magnetic and Keppel Island recovered to exceed before-harvest levels at 1 to 3 months. There also appears to be a temporal variation of approximately 15% to 25% percent cover over time at the control sites
KeppelandMagneticIslandsMonitoringReport12monthsafterharvest31Jan2024