Effects of light attenuation on the sponge holobiont- implications for dredging management.

ABSTRACT: Dredging and natural sediment resuspension events can cause high levels of turbidity, reducing the amount of light available for photosynthetic benthic biota. To determine how marine sponges respond to light attenuation, five species were experimentally exposed to a range of light treatments. Tolerance thresholds and capacity for recovery varied markedly amongst species. Whilst light attenuation had no effect on the heterotrophic species Stylissa flabelliformis and Ianthella basta, the phototrophic species Cliona orientalis and Carteriospongia foliascens discoloured (bleached) over a 28 day exposure period to very low light (<0.8 mol photons m^-2 d^-1). In darkness, both species discoloured within a few days, concomitant with reduced fluorescence yields, chlorophyll con

SUBMITTER: Pineda MC 

PROVIDER: S-EPMC5153652 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature