How are they able to survive in the harsher, colder waters of Sydney? Knowing this is fundamental to predicting how new species will shift into precious marine environments like Sydney as our climate changes and our oceans warm. The introduction or eradication of any species has flow on effects across the entire local ecosystem, so understanding species shifts is integral to mapping trophic flow and preserving any likely at-risk species.  

Sydney’s native coral, Plesiastrea versipora.

Humans, animals, and even plants, use fats to protect against the cold as insulation, or as an energy source when food is limited.  

To uncover if corals do the same, Masters student, Laura La Motta from The University of Technology Sydney (UTS) is investigating the fat composition of corals in a range of temperatures and nutrient levels.  

In collaboration with the Sydney Institute of Marine Science (SIMS), Laura is exploring how extreme hot and cold temperatures change the fat composition of a native Sydney stony coral, Plesiastrea versipora, and the subtropical intrusive coral, Pocillopora aliciae.  

This will help us understand how migrating corals are able to make Sydney their new home and what Sydney reefs might look like in future oceans. This will also inform how supported ecosystems change along with their coral hosts and what organisms we can expect to see in our backyard. 

In April this year, Laura conducted heat stress experiments in SIMS’ Ian Potter Research Aquarium to understand how corals cope when exposed to increased temperatures. Through August, Laura will be returning to SIMS with fresh samples from Manly’s North head to see if they can brave the cold with temperatures as low as 12C.