The evolution of the structure of these ecosystems was the subject of the first monograph of Charles Darwin.
The primary member of these ecosystems are preyed upon by Acanthaster planci, whose surface resembles a crown of thorns. The so-called "cement" of these ecosystems is a crustose, pink member of Rodophyta. The evolution of the structure of these ecosystems was the subject of the first monograph of Charles Darwin. Their primary members are in a mutualistic relationship with zooxanthellae. Of their three main types, the "fringing" type occupies a shallow zone of water while an (*) atoll is a lagoon surrounded by one. These ecosystems are threatened by widespread "bleaching". For 10 points, name these ecosystems primarily constituted of calcium carbonate secreted by corals, which form a giant "barrier" near Queensland, Australia.
The primary member of these ecosystems are preyed upon by Acanthaster planci, whose surface resembles a crown of thorns.
coral reefs [prompt on corals; prompt on oceans]