Corrigendum: Colony growth responses of the Caribbean octocoral, Pseudopterogorgia elisabethae, to harvesting. 122, 299–307

Abstract

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).

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.