Corals going extinct?

[jcook54]

Hey gang, one of the conversations we had last night around the dinner table was about the start of coral reefs globally. As the resident coral expert I was asked what I thought. I gave my "tripod" answer about global warming, depressed pH levels and environmental degradation and the conversation moved on. However, it got me thinking, we all have systems with different temperatures as well as varying pH levels so what gives? Can or will corals migrate to different areas of the ocean if it gets too warm? I'm imaging the Great Barrier Reef slowly crawling towards slightly cooler water temps. pH is another issue entirely but my display tank has always had pH levels of around 8.0 and I've long since quite chasing the number and just went by how things looked. Can corals survive another drop in pH? (From what I've read, the ocean's pH used to be 8.2 and now it's 8.0) This leave the 3rd leg of my 3-part answer still to deal with, environmental damage. Humans certainly have caused damage that we're still trying to figure out but that can be reversed. We need to stop doing it before that can happen but it's possible.

I've re-read the first paragraph and I really don't know how to better ask the question to not seem like such a dim bulb. Everything I've mentioned is WAY simplified and and there's a lot more conversation to be had but what do y'all think? Is there hope for wild corals reefs or are we keeping stuff that will someday be extinct in the wild? Also, I've always emphasized stability over number and if temp or pH changes a bit over the next 50 years, can't corals adapt?

 

[CJD18]

As I diver I have seen many dead/dying reefs that were healthy 10-15 years ago!

 

[Eric_n_Ga]

Reef's , like everything have dealt with this for millions of yrs . They will move and replenish . Certain species will flourish some will perish . Others we know little about will become more abundant . While diving in areas I've been in for 30,+ yrs there's life in places there never was and there's total vacancy in places there was once life . Also when you look at the age if out tanks vs the ocean it should show you how adaptive marine life is . We force things to adapt on a very very accelerated scale . This should be a promising sign that reef's will survive. Also keep in mind the ocean and it's biomass go through swings up and down just like any thing .

 

[ActiveAngel]

The current pH of the ocean isn’t necessarily responsible for the majority of coral death. Rather, it makes it increasingly challenging for them to build skeletons (same for bivalves). If current trends continue, it can exacerbate to the point of being the primary cause of death.

Heat may be the current largest cause for concern. One of many scientists studying this is Dr Louise Marcelino with Northwestern University; she has been developing a “bleaching response index” and cataloguing different coral species, their symbiotic algae, and how they respond to thermal challenges. She also investigates coral skeletons at a cellular level and how they disperse light in order to accommodate for environmental changes, and sometimes corals skeletons can actually work against them and kill them faster.

There is also the different between momentary heat (hours/days), and long-term heat over the course of months/years.

Additionally, many collected corals die after collection. Some of the ones in our tanks are those that are more resilient than their same-species counterparts in the oceans. That said, I’ve spoken with researchers about repopulating some reefs with previously local specimens from the aquarium trade that exhibit these resilient traits. Unfortunately, many of these ones that are resilient in our aquariums disproportionately do not make it in the wild. However, the mechanisms in place for this have yet to be determined the last I checked.

And yes, we recently have found small reefs forming where previously there were no reefs.

 

[ActiveAngel]

Reef's , like everything have dealt with this for millions of yrs . They will move and replenish . Certain species will flourish some will perish . Others we know little about will become more abundant . While diving in areas I've been in for 30,+ yrs there's life in places there never was and there's total vacancy in places there was once life . Also when you look at the age if out tanks vs the ocean it should show you how adaptive marine life is . We force things to adapt on a very very accelerated scale . This should be a promising sign that reef's will survive. Also keep in mind the ocean and it's biomass go through swings up and down just like any thing .

I absolutely love the optimism! but as a scientist, I unfortunately disagree with this. The rate at which we are changing the planet is too severe and corals just have too much going against them.

I do agree that life will continue. But that corals will survive the anthropogenic mass extinction event, I am more doubtful. There are many examples of more-adaptable animal groups that have been completely wiped out by lesser extinction events, by any and all measures. Nonetheless, I hope that they do.