Australian Institute of Marine Science

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% respectfully. Porites spp. cover was reduced by 3%. Hard coral cover showed signs of recovery from 2004 and reached 29% in 2011. This increase reflected early recovery of Porites spp. cover from 3% in 2000 to 9% by 2007, Within Acroporidae foliose Montipora spp had recovered to predisturbance levels, whereas bottlebrush Acropora spp. had not. The other major hard coral families have remained below 2% cover since 2000. Fluctuations in algae cover have mirrored changes in hard coral cover throughout the survey period, peaking in 2000 at 65%. In 2011 algae cover was 29% 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 at Fitzroy Island Reef in 2009 and 2011. No Drupella spp. were recorded in 2011. Bleaching was observed on individual colonies in both 2009 and 2011.