Latest findings from a study conducted by scientists at the University of Queensland in Brisbane showed slurry from farms in Australia had been contributing to the collapse of the corals in the Great Barrier Reef.
Slurry, as defined by Merriam-Webster, is a watery mixture of insoluble matter which includes mud, lime, or plaster of paris.
Findings from the study, published Nov. 6 in the Proceedings of the Royal Society B, said the corals collapsed between the 1920s and 1950s with the arrival and expansion of European settlement in Australia.
When the European settlers started to incorporate farming as their source of living, the runoff from these farms started slowly clouding the unspoiled waters off the Queensland coast, ultimately killing the natural branching coral species. In its place, a stunted, weedy type of coral spruced up.
"There was a very significant shift in the coral community composition that was associated with the colonization of Queensland," study co-author John Pandolfi, a marine biologist at the University of Queensland Australia, said.
Suffice to say, humans and their varied innovations had disrupted the ecology of the Great Barrier Reef, decades before climate change and reef tourism entered the vocabulary of environmentalists.
It was in the 1860s when Europeans began to colonize Queensland, Australia. They brought down forests to create a massive space for sheep grazing and sugar plantations. By the 1930s, huge amounts of fertilizer and pesticide-laden runoff had poured into the nearby ocean from the rivers.
Although natural occurrences such as cyclones kill coral, the extra nutrients present in the water also distort its physical, original conditions, making seaweed move in, and thus ultimately preventing coral from regenerating, Terry Done from the Australian Institute of Marine Science said.
For the study, the scientists at the University of Queensland took cores from three different reef sites. Two of the sites had little coral left after the 1950s, while the third had been colonized since then by different types, researchers said.
"They just weren't able to come back after the 1950s."