The following articles and video focus on the Great Barrier Reef, and in particular the massive negative impact of cattle grazing in its catchment areas. The articles can also be found in the section dealing with climate change and animal agriculture.
The accompanying video:
Meat Eaters vs the Great Barrier Reef 18 June 2017
Beef, the reef and rugby: We have a problem 26 March 2017
Are cows killing the reef? 3 April 2014
The issue was also addressed in my 2008 submission to the Victorian State Government.