Abstract: 

Increasing levels of suspended sediments pose a major threat to coral reefs. Suspended sediments have been linked to declines in abundance and diversity of coral reef fishes, yet the mechanisms driving these changes are not yet well understood. In my PhD, I examined how suspended sediments, in isolation and in combination with other stressors, may affect the gill morphology of coral reef fish juveniles, and the consequences this may have for aerobic performance and predator escape performance. I show that 1) suspended sediments have species-specific impacts on the gills and aerobic performance of fishes; 2) suspended sediments lead to an enhanced predator escape performance, likely due to an increased perceived predation risk of juveniles in turbid water; and 3) exposure to suspended sediments and elevated water temperatures or elevated water flow combined leads to unexpected interactive effects on the aerobic performance of fishes. Overall, the results of my thesis suggest that suspended sediments can have significant effects on the gill morphology and aerobic performance of coral reef fishes, which may potentially contribute to changes in fish populations in response to increasing levels of suspended sediments on inshore coral reefs.

Biography: 

Sybille is originally from Switzerland. She attended the University of Bern to complete a Bachelor’s degree in Ecology and Evolution, before moving to Australia for a Master’s degree in Marine Biology at James Cook University. Here, she completed a Minor Project under the supervision of Dr Amelia Wenger and A/Prof Jodie Rummer on the effects of poor water quality on clownfish larvae, which inspired her to start a PhD on the same topic. For her thesis, she is examining the effects of suspended sediments on the gill morphology and performance of coral reef fishes under the supervision of A/Prof Jodie Rummer, Dr Amelia Wenger and Dr Andrew Hoey.