"The Roast" is like an Australian version of "The Daily Show" but with heavier accents. These guys are clearly having a lot of fun here (you can find out about "nature's most spectacular orgy" at 4:18). But the topic they're taking on is in some serious need of attention: the Great Barrier Reef.
Needless to say, this is a fun explainer of everything that's going on with the Great Barrier Reef. However, it's worth pointing out that, contrary to what the video says at 5:04, dredge spoil is not from mines — it's just sediment from the bottom of the ocean. Don't get me wrong, it's still dangerous to the health of the Great Barrier Reef, but I feel like you deserve that distinction. OK, carry on and join the fight to save the reef!