Sponge microbiomes – are they affected by pollution?

Microbes account for a large proportion of the biomass of marine sponges. The microbial assemblages in marine sponges have been shown to be affected by factors such as temperature extremes, disease and heavy metal pollution.

Gantt et al. (2017) conducted a study where they sampled microbes associated with the sponge Crambe crambe and from the ambient seawater in 2 locations: a polluted harbour in Blanes, Spain and a nearby natural environment. They hypothesized that the microbiomes of the sponge would differ in the polluted and unpolluted area.

16S rRNA sequences were amplified and sequenced using Illumina and no difference in microbial community structure in sponges between the sample sites was found; whereas there was a difference between ambient sea water at the two sites. The microbial community in the sponges differed from the ambient sea water at both locations.

It was suggested that the results may indicate that sponge microbiomes are much more stable and pollutant-tolerant than previously thought. However, other similar studies on other species of sponge have found the microbiomes to be affected by pollution so to further this study I would suggest sampling from multiple polluted sites in the area to see if the trend found still stands.

Gantt, S., López-Legentil, S., Erwin, P. (2017). Stable microbial communities in the sponge Crambe crambe from inside and outside a polluted Mediterranean harbor. FEMS Microbiology Letters, 364(11).