Evans, S.M., McKenna, C., Simpson, S.D., Tournois, J., & Genner, M.J. (2016) Patterns of species range evolution in Indo-Pacific reef assemblages reveal the Coral Triangle as a net source of transoceanic diversity. Biology letters, 12.
The authors began by discussing how it is crucial to understand the causes of spatial distributions of biodiversity when studying an ecosystem. They applied this idea to study the species richness of the Coral Triangle, located in the Indo-Pacific region. The purpose of the study was to evaluate if the Coral Triangle is a net source of marine biodiversity. The authors specifically hypothesized that if this location has acted as a net source, then the populations closest to the Coral Triangle have been the earliest establishments, therefore are older, and that as the distance from the region increased the relative age of the populations will decrease.
The authors used published population-level data from Genbank and yielded data from 45 different populations of reef-associated species with varying distances from the center of the Coral Triangle. They statistically analyzed the data and created a regression line to fit the relationship between the distance from the center of the Coral Triangle and the relative time of the population’s establishment.
The populations with the earliest establishment were found to be closer to the estimated center of the Coral Triangle than “younger” populations that have had more recent establishment. The data supports the authors’ original hypothesis that the Coral Triangle has been a net source of reef-associated biodiversity, and they state that it’s achieved this by serving as a center of origin or survival for these species.
Significance to Palau:
The research and findings in the study described by this paper are significant because as coral reef species continue to face challenges such as habitat loss, ocean acidification and global climate change, regions that can act as a center for survival must be recognized and preserved.
Palau is technically not located in the Coral triangle, however Koror, Palau is only about 8◦ 6’ N, 1◦ E of the estimated center of the Coral Triangle given in the paper. Palau possesses an incredible diversity of marine organisms. For example, it has been estimated by the Coral Reef Research Foundation that Palau has up to 425 species of stony corals and 137 species of sea squirts alone. This paper may be of interest to those studying and practicing conservation of invertebrates in Palau because of the nation’s extensive coral reefs, marine biodiversity, and proximity to the Coral Triangle. Understanding how populations in the waters around Palau relate to those studied in the paper could provide insight on the relative time of establishment of the populations.