Comment by kbutler
2 hours ago
Happy to report the northern and central GBR coral cover is currently higher than any time measured before 2020. Southern is currently below its long-term average, but 2024 was a record high in coral cover.
https://www.aims.gov.au/monitoring-great-barrier-reef/gbr-co...
This doesn't mean everything is fine, but it is doing way better than 2017.
I wonder if coral coverage is a meaningful stat itself. Does that directly translate to diversified creatures?
Was in central GBR this year, can't say I'm super impressed but not sure how I should set my expectation
Not necessarily but they do measure diversity too, and it has not changed dramatically.
Typically the biggest change in diversity is due to cyclones which kill of the delicate and fast-growing corals like staghorns, which are also the fastest to grow back.
Wow, I wasn’t aware of this. I’ve always read climate change as the primary driver for bleaching. If that is the case, do we know why/how they’ve recovered?
Corals are killed en masse by other events, particularly cyclones. These have a much bigger affect on coral coverage, in the short term, than ocean temperatures / bleaching (which is transient and more localized).
Bleaching is not death of the coral, it is the expulsion of algae (typically in high temperatures). The coral can find a different species of algae, or the algae can return once temperatures drop.
There are corals living in regions of the ocean with different temperatures, so it is not that high temperature alone would kill all coral, but populations adapted to a given region (like north vs south GBR) are being affected by the speed of the changes.