Fig 1.
Study location between Palfrey and South islands, in the Lizard Island group, Great Barrier Reef (A), illustration representing the reef habitats across the reef profile at the study location (B), and a photograph showing a series of Scarus parrotfish scars on a massive Porites coral (C). Photographs taken by Victor Huertas.
Fig 2.
Changes in the benthic cover at Lizard Island, on the Great Barrier Reef.
Percentage of reef substratum occupied by massive Porites (filled) and other hard corals (empty) in 2008 and 2018. Purple, red, orange, and yellow indicate the slope, crest, flat, and back reef habitats, respectively. Values above the bars indicate the percentage of massive Porites cover relative to total coral cover for the respective habitat.
Table 1.
Percentage of live hard coral cover in 2008 and 2018 at the study site, Lizard Island, on the Great Barrier Reef.
Data for 2008 sourced from [24].
Fig 3.
Parrotfish abundance and predation pressure on corals across the study location at Lizard Island, on the Great Barrier Reef.
(A) Violin plots representing parrotfish abundance in 2008 (grey) and 2018 (coloured). Horizontal lines indicate the mean. Circles are individual samples. NS: statistically non-significant; *: statistically significant. (B) Predation pressure on massive Porites on the slope, crest, flat and back reef zones at the study site in 2008 (grey) and 2018 (coloured). Circles represent the mean number of scars m-2 and lines indicate the standard error of the mean. Data from 2008 were sourced from [24]. Purple, red, orange, and yellow indicate the slope, crest, flat, and back reef habitats, respectively.
Fig 4.
Parrotfish predation pressure on massive Porites at Lizard Island, Great Barrier Reef.
(A) The relationship between the number of scars and the size of massive Porites colonies. Fitted lines and bands are, respectively, generalised linear model fits and their 95% confidence interval. (B) The relationship between the density of parrotfish scars and the colony surface area. Note that axes are on a log scale and reveal the exceptionally high scar density on small colonies. (C) Examples of small (left) and large (right) massive Porites colonies at the study site. The same ruler is featured as a scale in both images. Scars are outlined in green and planar colony surface area in white. Scalebars = 5 cm. Purple, red, orange, and yellow indicate the slope, crest, flat, and back reef habitats, respectively.