Great Barrier Reef Climate Change

Climate change is the biggest long-term threat to the Great Barrier Reef and coral reefs worldwide, according to the Reef 2050 Long-Term Sustainability Plan. It has caused sea temperature increases, ocean acidification, altered weather patterns, and rising sea levels. The sea temperature increases affect many species. It causes coral bleaching to occur, which is when the microscopic algae separates from coral, taking the color, as well as the energy away. It affects the photosynthesis and reproduction of seagrass, the reproduction of coral, and enables a range of microscopic organisms that cause disease to thrive. It affects the reproduction of fish - because they have a narrow temperature range in order to reproduce effectively -, the sex

It affects seabirds as well. They can have fewer breeding cycles, slowed chick development, and a decrease in nesting success. On Raine Island, there has been a steady decline in population of the biggest seabird nesting colony in the Great Barrier Reef - which has been recorded over the last twelve years. “The cause is unknown, however in the absence of human interference and apparent good nesting conditions at the site, the most likely option is a decline in marine food resources due to the changing climate and overfishing.” Temperature affects the animal physiology, including metabolic rate and timing of reproduction in sponges, sea squirts, molluscs, polychaete worms, and other invertebrate species. Immobile creatures, like sponges, sea cucumbers, and giant clams will be in danger of surviving. Climate change will affect ocean circulation patterns which will affect the supply and distribution of nutrients to food-webs and the distribution of eggs and larvae in coral reefs. When the surface of the water heats up, it becomes more dense and doesn’t mix with the cooler water below, making it hard for nutrients from the bottom of the ocean to travel up towards the phytoplankton on the