Blake Ramsby - AIMS@JCU

Blake Ramsby

blake.ramsby@my.jcu.edu.au

PhD
College of Science and Engineering

Blake Ramsby

blake.ramsby@my.jcu.edu.au

PhD
College of Science and Engineering
The effects of a changing marine environment on the bioeroding sponge Cliona orientalis

Blake completed a BSc in Biology at the University of Richmond (Virginia, USA). As an undergraduate, he investigated the effects of elevated temperature on bio-eroding sponges of the Florida Keys under the supervision of Dr. Malcolm Hill. Blake recently completed a M.Sc. degree at the University of Mississippi under the supervision of Dr. Tamar L. Goulet, where he conducted experiments to test the effects of elevated temperature on photosynthesis in Caribbean octocorals. In particular, he measured photochemical efficiency, oxygen evolution, and light absorption of octocorals under ambient and elevated temperatures.

The effects of a changing marine environment on the bioeroding sponge Cliona orientalis

2014 to 2017

Project Description

The aims of this project were to determine the effects of warming, nutrients, and light on the distribution, physiology, and symbioses of sponges, with a focus on the bioeroding sponge Cliona orientalis, which breaks down coral reef structure.

Project Importance

Climate change threatens coral growth and survival but sponges may be more tolerant of climate stressors. If sponges can survive climate change, and understanding what sponge characteristics may be affected, can provide insight into their function on coral reefs of the future.

Project Methods

The effects of environmental stressors on sponges were studied by relating sponge abundance to local environmental characteristics on the inshore GBR, using laboratory experiments to determine the effect of warming, nutrients, and light on sponge symbioses and growth. Sponge symbioses were studied using oxygen flux to measure photosynthesis and respiration and sponge condition was tracked using protein and organic contents of sponge tissue. Changes to sponge microbial communities were evaluated using next generation sequencing of 16S rRNA.

Project Results

We found that C. orientalis bleached at a similar temperature to the more tolerant corals in the area, suggesting that it will also be adversely affected by ocean warming. Bleaching severely disrupted all symbioses within the sponge and they were not recovered.

Keywords

Algae,
Bacteria,
Benthic,
Biostatistics,
Climate change,
Coral reefs,
Corals,
Distribution,
Ecology,
Genetics,
Interaction,
Manipulative experiments,
Mapping,
Microbial,
Microbiology,
Modelling,
Molecular techniques,
Monitoring,
Ocean warming,
Physiology,
Pollution,
Porifera (sponges)