Changes in the metabolic potential of the sponge microbiome under ocean acidification

This study investigated the changes occurring in the functional potential of the microbiome of two marine sponge species living in low pH, "acidified" waters and adjacent (~ 500m away) ,"control" waters, at shallow coral reefs CO2 seep sites in Papua New Guinea.

Field work was carried out in the Milne Bay Province in the d'Entrecasteaux Channel in Papua New Guinea at a depth of 5m. Control site GPS coordinates: 9.828217 S 150.820517 E, Seep site GPS coordinates: 9.8241 S 150.825833 E.

Three samples of each of two sponge species were collected. The species were Coelocarteria singaporensis and Stylissa flabelliformis. These particular species were chosen based on a previous study (Morrow et al., 2015) characterizeing the microbial communities of the 2 species at these particular field sites.

Sample size of three samples per species was chosen based on the following criteria:

1) minimizing impact on the field site
2) accounting for statistical testing sample size requirements
3) space availability for storage in the field and during transport
4) cost (temporal and financial) of sample processing and sequencing

Environmental data were collected over multiple expeditions as well as via remote loggers. Data was collected in August-2010, January 2013 and betweek December 2011-April 2014. For more information on environmental data for this study, please see Supplementary tables 3, 3 and 4.

Microbial functions of the two sponge species of the seep and control sites were compared, including transport of carbon and host derived compounds, carbon fixation and carbonic anhydrase, nitrogen and sulfur metabolism.