Analyses of mean densities of chlorophyll-a for each treatment 14 or 42 days after the start of the experiment.*

*Macroalgae (Ma) was fixed with 2 levels (+/−); Treatment (Tr) was fixed and orthogonal with 5 levels; Plots (Pl) was nested in Ma x Tr with 3 levels (n = 10). Plots had 2 levels for analysis at 42 days because 1 plot was lost during a storm; so, 1 plot was excluded at random from all other treatments to balance the design. Cochran's test (C) was used to test assumptions of homogeneity. Non-significant interactions were pooled when ns with PPP>0.05.