The status of one of the most complex ecosystems on the planet has been officially downgraded. The Great Barrier Reef Marine Park Authority’s condition report, which is updated every five years said that the health of the Great Barrier Reef has been downgraded from “poor” to “very poor.” According to the report, habitat loss has already affected populations of some species dependent on the reef, like reef fish, marine turtles, and seabirds.
The Great Barrier Reef is a 2,300-kilometer-long coral network off the coast of northeast Australia. In addition to protecting coastlines from waves, storms, and floods by providing a buffer and barrier, the reef contributes AUS$5.4 billion (US$4.8 billion) annually to the Australian economy through tourism, fishing, and scientific research. Government data shows that 67,000 jobs are supported by the reef.
The report lists rising sea temperatures being the most immediate threat to the reef, as coral reefs are extremely sensitive to warming ocean temperatures. High water temperatures cause the coral to expel tiny algae, causing coral to appear white in an event called coral bleaching. The white coral is at risk of dying if the water temperature doesn’t return to normal. There have been four major bleaching events in the past two decades, with major events occurring both in 2016 and 2017.
Without significant improvement in the climate change trajectory, the report estimates that the reef could face major marine heatwaves every year. Seagrass meadows could experience major losses and by 2030, the reef could look more drab, with fewer fish. The scientists said in the report: “Initiatives that will halt and reverse the effects of climate change at a global level and effectively improve water quality at a regional scale are the most urgent to improve the Region’s long-term outlook.”
There was some good news included in the report. Water quality is showing signs of improvement in some areas impacting the reef. The report also noted that conservation efforts were resulting in the recovery of populations of humpback whales and southern green sea turtles.