Meeting Abstract
In the ocean, environmental variation in light and temperature can influence the genetic diversity and structure of plankton communities. Here, we aimed to characterize environmental variation and its influence on plankton communities from the Bocas Del Toro Archipelago reef complex in Panamá. We visited eight reef sites: four inshore and four offshore reefs to characterize variation in thermal and light profiles across sites. Temperature loggers were deployed at each reef site for one year and a light data logger was deployed at each site at midday to quantify noon light values. Plankton tows were conducted in triplicate at midday and 18S DNA metabarcoding was used to characterize plankton communities. In addition, at STRI Point, plankton communities were characterized in the morning and evening in order to investigate the effect of time of day. We found that inshore sites exhibited larger variation in temperature, while offshore sites exhibited increased light levels. However, these environmental differences across reef type did not drive differences in plankton communities. We found no significant differences in overall plankton community composition or genetic diversity across time of day, reef type (inshore/offshore), or reef site. Instead we found that several specific taxa were significantly enriched at different sites, but overall plankton communities appear relatively panmictic across our study sites. This study is limited to taxonomic differences detectable by 18S metabarcoding: the possibility of selection on other genetic loci within these taxa remains a possibility and future work should investigate fine scale population structure within a genus.
