What are 7 reasons why the Pacific reef systems are in decline?

Australia has four families of native frogs and one introduced toad, the Cane Toad. In 1935 the Cane Toad was introduced to Australia in a failed attempt to control pests in sugarcane crops. It has since become a devastating pest, spreading across northern Australia. As well as competing with native insectivores for food, the Cane Toad produces a venom that is toxic to native fauna, as well as to humans. The Myobatrachidae, or southern frogs, are Australia's largest group of frogs, with 120 species from 21 genera. A notable member of this group is the colourful and endangered Corroboree Frog. The tree frogs, from family Hylidae, are common in high rainfall areas on the north and east coasts; there are 77 Australian species from three genera. The 18 species from two genera of the Microhylidae frogs are restricted to the rainforests; the smallest species, the Scanty Frog, is from this family. There is a single species from the world's dominant frog group, family Ranidae — the Australian Wood Frog — which only occurs in the Queensland rainforests. As elsewhere, there has been a precipitous decline in Australia's frog populations in recent years. Although the full reasons for the decline are uncertain, it can be at least partly attributed to the fatal amphibian fungal disease chytridiomycosis.