**3. Results**

## *3.1. Benthic Survey*

Transects ranged from 5 to 34 meters in length, with 1219 observations recorded at one-meter intervals along the fringing reef in both 2000 and 2018. Six species of coral (i.e., *Porites compressa, Porites lobata, Montipora capitata, Lobactis* (formally *Fungia*) *scutaria, Pocillopora damicornis, Pocillopora meandrina*) were recorded at the site in 2000 and four (i.e., *P. compressa, M. capitata, P. damicornis, Leptastrea purpurea*) were recorded in 2018. Four species of macroalgae (i.e., *Dictyosphaeria cavernosa, Dictyosphaeria versluyii, Gracilaria salicornia, Kappaphycus alvarezii*) were present in 2000 and two (i.e., *D. cavernosa, D. versluyii*) were present in 2018. Unidentified species of turf algae, crustose coralline algae, and mixed sand and rubble were present in both surveys and were marked as such.

### *3.2. Statistical Analysis*

#### 3.2.1. Abiotic and Biotic Changes

The mean daily temperature (mean ± SE) at Moku o Lo'e increased from 24.07 ± 0.07 ◦C in 2000 to 25.03 ± 0.02 ◦C in 2018 (*p* < 0.0001), despite no evident general trend across years (R<sup>2</sup>=0.1852) (Figure 2). The overall community composition across the fringing reef changed from 2000 to 2018 (PERMANOVA *p* < 0.05, PERMDISP *p* < 0.05) (Figure 3, Table 1). Total mixed sand cover decreased significantly from 12 ± 1.9% to 4.6 ± 1.0% from 2000 to 2018 (*p* < 0.0001) (Figures 4 and 5). This is further supported by a break in the fringing reef in 2000 (represented as a transect with 100% sand cover), which was not observed in the 2018 survey.

**Table 1.** PERMANOVA model results based on a Bray–Curtis similarity matrix comparing benthic communities between years (fixed factor) and transect section (random factor nested within year). Significant p values (*p* < 0.05) are bolded.


**Figure 2.** Average annual daily mean seawater temperature (◦C) at Moku o Lo'e (Coconut Island) at the Hawai'i Institute of Marine Biology from 2000–2018. Data retrieved from (http://www.pacioos. hawaii.edu/weather/obs-mokuoloe/).

**Figure 3.** Non-metric multidimensional scaling (NMDS) ordination plot representing the benthic communities from the 2000 and 2018 surveys in convex hulls (Dimensions = 2, Stress = 0.19). Each point represents one transect (n = 60).

**Figure 4.** Mean Percent cover of each species or category in 2000 vs. 2018. Each standard error bar is one standard error from the mean. \* Indicates significant difference between years at *p* < 0.05.

**Figure 5.** Spatial trends in (**a**) Total benthic cover and (**b**) coral species composition. (**A.**) represents data from the 2000 survey and (**B.**) represents data from the 2018 survey. Each pie chart represents the average from 10 transects in that section. Photo credit: Digital Globe
