Erratum to: Colony growth responses of the Caribbean octocoral, Pseudopterogorgia elisabethae, to harvesting (Invertebrate Biology, 122, 4, (299-307), 10.1111/j.1744-7410.2003.tb00094.x)

In the article by Castanaro and Lasker (2003), errors were made in scaling of some of the images. The errors were discovered while examining the data for another project. We remeasured the photos and reanalyzed the data. Some results differed slightly from those reported in the original publication. Growth rates were generally higher than reported in the original analyses, and the proportion of branches that suffered negative growth was lower in the reanalysis. The primary result (that clipped colonies had greater rates of branch origination) was unchanged, but in the reanalysis we found that the magnitude of that effect was different between the two study sites. We also report differences between new and old branches in the linear growth rate that depended on the treatment. Branches present at the time of the clipping had higher growth on clipped colonies compared to similar branches on unclipped colonies, probably reflecting the conversion of existing branches to actively growing source branches (also called mother branches). Caribbean Pseudopterogorgia spp. have been reassigned to the genus Antillogorgia, and references to Pseudopterogorgia have been changed accordingly. Of the colonies from Abaco, 12 of the 15 that were clipped to four branches and 10 of those clipped to 10 branches were used in the new analyses. All 28 of the original control colonies were used. Four of the images used in the original analysis of the colonies from San Salvador were lost, and consequently the reanalyses are based on nine of the 15 colonies that were clipped to four branches, 14 colonies that were clipped to 10 branches, and 11 unclipped controls. We used the program ImageJ (Schneider et al., 2012) to label and measure photos of colonies, and we used the vegan package (v2.5-6; Oksanen et al., 2019) in R 3.6.3 (R Core Team, 2020) to conduct new permutational analyses of variance (PERMANOVA). RESULTS We reanalyzed 2281 branches that were present on colonies at the start of the experiment identified from the 1999 photos of the colonies used in the analyses. Fewer of the branches had negative growth than reported in the original publication. Overall, 64.3% had positive growth and 35.1% had negative growth. More branches on severely clipped colonies (reduced to four branches; 72.4%) underwent positive growth compared to colonies that were clipped to 10 branches (65.3%) or not clipped (62.6%). Similar levels of positive growth occurred at the Abaco (64.7%) and San Salvador (63.5%) sites. Branch extension Unlike the results originally reported, there was a significant interaction between branch age and treatment in branch extension rate (corrected Figure 2) at both Abaco (F_2,2339 = 9.77, p =.001) and San Salvador (F_2,896 = 4.73, p =.009), as well as differences among colonies within treatment at Abaco (F_3,2339 = 8.57, p =.001) and San Salvador (F_3,896 = 7.12, p =.001). 2 FIGURE (Figure presented.) Annual branch extension in colonies of Antillogorgia elisabethae from Abaco and San Salvador, Bahamas, subjected to differing levels of clipping. Error bars are standard errors When colonies that were not clipped were removed from the analysis, and the study site was added as a factor, branch age still significantly affected branch extension (F_1,1178= 67.761, p =.001). The effects of study site (F_1,1178 = 2.590, p = 1.000) and treatment (F_1,1,178 = 0.000, p =.991) were no longer significant, but there were interactions between branch age and study site (F_1,1,178 = 6.513, p =.020) and between branch age and treatment (F_1,1178 = 4.789, p =.031). Branch origination There were significant treatment effects on per capita branching rate at both Abaco (F_2,47 = 26.107, p =.001) and San Salvador (F_2,31 = 24.577, p =.001). In a secondary analysis, colonies that were not clipped were removed and study site was included in the model. Site (F_1,41 = 7.791, p =.005) and treatment (F_1,41 = 7.741, p =.006) had significant effects, and there was a small interaction between site and treatment (F_1,41 = 4.04, p =.051). Clipped colonies at Abaco had similar per capita branching rates. At San Salvador, the most severely clipped colonies had the highest per capita branching rates (corrected Figure 3A). 3 FIGURE (Figure presented.) Branching in colonies of Antillogorgia elisabethae from Abaco and San Salvador, Bahamas, subjected to differing levels of clipping. Branching is expressed as a per capita rate based on the number of branches present on the colony immediately after the experiment was initiated (A) and as the number of branches produced on source or mother branches, those branches that produced new branches (B). The number of mother branches on colonies at the end of the experiment is also shown (C). Error bars are standard errors There was also a significant interaction between the effects of study site and treatment on the number of new branches per source branch (F_2,419 = 4.279, p =.034). Moderately clipped colonies from Abaco (clipped to 10 branches) had more new branches per mother branch in comparison to moderately clipped colonies from San Salvador and to severely clipped colonies at both sites (which had similar numbers of new branches per source branch; corrected Figure 3B). The number of mother branches per colony was also affected by an interaction between site and treatment (F_2,419 = 4.338, p =.039). As with the number of new branches per mother branch, moderately clipped colonies at Abaco had more mother branches at the end of the experiment in comparison to moderately clipped colonies at San Salvador and to severely clipped colonies at both sites (which had similar numbers of mother branches; corrected Figure 3C). The differences among colonies in total number of mother branches had only a small effect on the overall number of new branches generated on each mother branch (corrected Figure 4). 4 FIGURE (Figure presented.) Numbers of new branches generated on mother branches as a function of number of mother branches on colonies of Antillogorgia elisabethae from Abaco and San Salvador, Bahamas, subjected to differing levels of clipping. Error bars are standard errors Total growth There was no significant effect of site or treatment on total growth over the course of the experiment (corrected Figure 5, F_2,78 = 2.15, p =.166). But, as with effects on branching, moderately clipped colonies from Abaco had the highest total growth, while the more severely clipped colonies had lower growth than colonies that had not been clipped. Total growth was similar across all levels of clipping for colonies from San Salvador and was generally lower than growth for colonies from Abaco, except for the most severely clipped colonies. 5 FIGURE (Figure presented.) Cumulative growth summed across all branches of colonies of Antillogorgia elisabethae from Abaco and San Salvador, Bahamas, subjected to differing levels of clipping. Error bars are standard errors Branch extension Unlike the results originally reported, there was a significant interaction between branch age and treatment in branch extension rate (corrected Figure 2) at both Abaco (F_2,2339 = 9.77, p =.001) and San Salvador (F_2,896 = 4.73, p =.009), as well as differences among colonies within treatment at Abaco (F_3,2339 = 8.57, p =.001) and San Salvador (F_3,896 = 7.12, p =.001). 2 FIGURE (Figure presented.) Annual branch extension in colonies of Antillogorgia elisabethae from Abaco and San Salvador, Bahamas, subjected to differing levels of clipping. Error bars are standard errors When colonies that were not clipped were removed from the analysis, and the study site was added as a factor, branch age still significantly affected branch extension (F_1,1178= 67.761, p =.001). The effects of study site (F_1,1178 = 2.590, p = 1.000) and treatment (F_1,1,178 = 0.000, p =.991) were no longer significant, but there were interactions between branch age and study site (F_1,1,178 = 6.513, p =.020) and between branch age and treatment (F_1,1178 = 4.789, p =.031). Branch origination There were significant treatment effects on per capita branching rate at both Abaco (F_2,47 = 26.107, p =.001) and San Salvador (F_2,31 = 24.577, p =.001). In a secondary analysis, colonies that were not clipped were removed and study site was included in the model. Site (F_1,41 = 7.791, p =.005) and treatment (F_1,41 = 7.741, p =.006) had significant effects, and there was a small interaction between site and treatment (F_1,41 = 4.04, p =.051). Clipped colonies at Abaco had similar per capita branching rates. At San Salvador, the most severely clipped colonies had the highest per capita branching rates (corrected Figure 3A). 3 FIGURE (Figure presented.) Branching in colonies of Antillogorgia elisabethae from Abaco and San Salvador, Bahamas, subjected to differing levels of clipping. Branching is expressed as a per capita rate based on the number of branches present on the colony immediately after the experiment was initiated (A) and as the number of branches produced on source or mother branches, those branches that produced new branches (B). The number of mother branches on colonies at the end of the experiment is also shown (C). Error bars are standard errors There was also a significant interaction between the effects of study site and treatment on the number of new branches per source branch (F_2,419 = 4.279, p =.034). Moderately clipped colonies from Abaco (clipped to 10 branches) had more new branches per mother branch in comparison to moderately clipped colonies from San Salvador and to severely clipped colonies at both sites (which had similar numbers of new branches per source branch; corrected Figure 3B). The number of mother branches per colony was also affected by an interaction between site and treatment (F_2,419 = 4.338, p =.039). As with the number of new branches per mother branch, moderately clipped colonies at Abaco had more mother branches at the end of the experiment in comparison to moderately clipped colonies at San Salvador and to severely clipped colonies at both sites (which had similar numbers of mother branches; corrected Figure 3C). The differences among colonies in total number of mother branches had only a small effect on the overall number of new branches generated on each mother branch (corrected Figure 4). 4 FIGURE (Figure presented.) Numbers of new branches generated on mother branches as a function of number of mother branches on colonies of Antillogorgia elisabethae from Abaco and San Salvador, Bahamas, subjected to differing levels of clipping. Error bars are standard errors Total growth There was no significant effect of site or treatment on total growth over the course of the experiment (corrected Figure 5, F_2,78 = 2.15, p =.166). But, as with effects on branching, moderately clipped colonies from Abaco had the highest total growth, while the more severely clipped colonies had lower growth than colonies that had not been clipped. Total growth was similar across all levels of clipping for colonies from San Salvador and was generally lower than growth for colonies from Abaco, except for the most severely clipped colonies. 5 FIGURE (Figure presented.) Cumulative growth summed across all branches of colonies of Antillogorgia elisabethae from Abaco and San Salvador, Bahamas, subjected to differing levels of clipping. Error bars are standard errors ACKNOWLEDGMENTS The original research was conducted with support from the National Undersea Research Center, the New York Sea Grant Institute and Lipo Chemicals Inc. The reanalyses were supported by National Science Foundation Grant OCE 17-56381.