FITZROY IS REEF

Intensive Surveys: Trends in cover of benthic organisms

Hard coral cover at Fitzroy Island Reef peaked at 36% in 1997. Bleaching combined with COTS feeding activity caused hard coral cover to drop from 32% in 1999 to 7% in 2000. Coral cover was reduced in all four main hard coral families but the impact was particularly severe for the dominant group, Acroporidae. Bottlebrush Acropora spp. and Montipora spp. declined by 6% and 4% respectively. Porites spp. cover was reduced by 3%. Hard coral cover showed signs of recovery from 2004 and reached 29% in 2011. This increase reflected increase in cover of Porites spp. from 3% in 2000 to 9% by 2007. Within the Acroporidae, foliose Montipora spp had recovered to pre-disturbance levels, whereas bottlebrush Acropora spp. had not. The other major hard coral families have remained below 2% cover since 2000. In 2013, recovery of hard coral cover had stalled and 57 Crown-of-Thorns Starfish were recorded on transects. Fluctuations in algae cover have mirrored changes in hard coral cover throughout the survey period, peaking in 2000 at 65%. In 2013 algae cover was 39% and the community was comprised primarily of turf species. The cover of soft corals has fluctuated around 20% throughout the survey period. Low levels of white syndrome were recorded from 2009-2013. The density of Drupella spp. was 20/ha in 2013.