Effects of ocean acidification on a sponge/coral species interaction
Decreasing ocean pH will dramatically affect benthic marine organisms that use calcium carbonate to build their skeletons and shells. While this will entail major changes between species and their physical environment, evidence suggests that interactions between species will also be influenced. One important species interaction in coral reefs is that between the coral, Porites furcata, and sponge, Cliona varians, which have opposing ecosystem roles; P. furcata creates reef structure through the accretion of calcium carbonate, while C. varians bioerodes calcium carbonate substrates. On healthy reefs, accretion and bioerosion are approximately equal. However, increased temperature and decreased pH stressful to corals may promote excavation in Clionaid sponges, shifting the calcium carbonate accretion/erosion balance to the detriment of coral reefs.
In collaboration with Amber Stubler at SUNY Stony Brook I am examining the effects of climate change on the species interaction between P. furcata and C. varians using phenotypic and genomic data. In the summer of 2013, we conducted a long-term mesocosm experiment at the Smithsonian Tropical Research Institute marine lab in Bocas del Toro, Panama in which coral and sponge individuals were exposed to climate change (increased temperature, decreased pH) and ambient conditions (pictured at top). We aim to answer the following questions:
Click here for a video and here for a paper describing the pilot study for this project.
Decreasing ocean pH will dramatically affect benthic marine organisms that use calcium carbonate to build their skeletons and shells. While this will entail major changes between species and their physical environment, evidence suggests that interactions between species will also be influenced. One important species interaction in coral reefs is that between the coral, Porites furcata, and sponge, Cliona varians, which have opposing ecosystem roles; P. furcata creates reef structure through the accretion of calcium carbonate, while C. varians bioerodes calcium carbonate substrates. On healthy reefs, accretion and bioerosion are approximately equal. However, increased temperature and decreased pH stressful to corals may promote excavation in Clionaid sponges, shifting the calcium carbonate accretion/erosion balance to the detriment of coral reefs.
In collaboration with Amber Stubler at SUNY Stony Brook I am examining the effects of climate change on the species interaction between P. furcata and C. varians using phenotypic and genomic data. In the summer of 2013, we conducted a long-term mesocosm experiment at the Smithsonian Tropical Research Institute marine lab in Bocas del Toro, Panama in which coral and sponge individuals were exposed to climate change (increased temperature, decreased pH) and ambient conditions (pictured at top). We aim to answer the following questions:
- do sponges bioerode calcium carbonate faster in climate change versus ambient conditions?
- are sponge bioerosion rates higher on coral skeleton versus live coral?
- what is the effect of climate change on calcification rates in the coral?
- does the transcriptional response of the coral to sponge overgrowth differ between climate change versus ambient conditions?
- are there differences in gene expression when sponges grow over live coral versus coral skeleton?
Click here for a video and here for a paper describing the pilot study for this project.