The great barrier reef’s fragile ecosystem is at risk of plankton and algae overgrowth. the main cause of this issue is
a.
climate change
b.
deforestation
c.
fallout contamination
d.
nuclear testing

climate change

Explanation:

warmer waters and higher water levels due to melting ice caps are very dangrous because of how fragile the corral is

The correct answer is A. The Great Barrier Reef's fragile ecosystem is at risk of plankton and algae overgrowth. The main cause of this issue is climate change.

Explanation:

Great Barrier Reef is the largest coral reef in the world, located in the Coral Sea off the Queensland coast in northeastern Australia.

The Great Barrier Reef has been hit by climate change, acidification and warming of waters. According to an article published by National Geographic in August 2018, up to half of the corals have died.

Another threat to the coral reef is so-called coral bleaching, which means that the corals become white and that the animals inside them die. It may be due to global warming, but there are probably other contributing causes, such as the coral being exposed to unusually high light intensity.