What is the fine-grained topic of the following text: Speaking to CNN, Southern Cross University (Australia) professor Peter Harrison said that the results of the preliminary tests have been encouraging and “exciting” so far, as the process “significantly increased” baby coral numbers in certain parts of the Great Barrier Reef, particularly Heron Island and One Tree Island, 18 months after laying millions of coral larvae in the areas. Only return the topic.
Preliminary tests significantly increasing baby coral numbers in parts of the Great Barrier Reef