The MacKinnon Lists Technique: An efficient new method for rapidly assessing biodiversity and species abundance ranks in the marine environment

Multivariate analysis The square-root transformed relative abundance data generated from all the deployments with each method analysed separately, showed the same significant differences in fish assemblage composition for the factors conservation status and depth with both methods. The random factor video was highly significant for MLT (Table 5). Following this analysis, we randomly dropped the number of videos used in the analysis, allowing us to investigate how MaxN and MLT perform at lower sampling efforts (Table 6). Both techniques found significant differences between status and depth at a balanced sampling effort of five video deployments per habitat. However, MLT found a highly significant differ- ence for the interaction between status and depth. MLT continued to detect the effect of pro- tection status, depth and their interaction as significant with a further reduction in sampling effort to three videos per habitat. While MaxN only detected a significant effect of status with no significant differences between depth and no interactions. Discussion For the first time, we have tested the ability of the MacKinnon Lists Technique to generate use- ful results on biodiversity patterns in marine fish communities. Our results show that this new approach is able to generate comparable results to the well-established MaxN methodology, with species richness estimates, diversity indices, relative abundance and assemblage composi- tion results similar between the two methods. Moreover, MLT continued to detect more key

Fig 2. Mean relative abundance for MaxN (average MaxN per video deployment) and MLT (fraction of lists the species occurred in within videos) in each habitat of the most important fishing targeted species. https://doi.org/10.1371/journal.pone.0231820.g002 PLOS ONE A new method for monitoring marine biodiversity PLOS ONE | https://doi.org/10.1371/journal.pone.0231820 April 22, 2020 9 / 15