[Coral-List] what does this new analysis tell us???
Douglas Fenner
douglasfennertassi at gmail.com
Fri Feb 4 20:48:01 UTC 2022
Ryan,
Good points!! Thanks very much! Well, the way I read the graph, the
decline from the 1998 El Nino mass bleaching was followed by recovery
(probably driven by recovery in the Indian O and places like Palau). Then
another decline began. It might have bottomed out, there is an uptick at
the very end. Could well be a temporary uptick. My feeling is that any
recovery now is likely to be temporary, and that the massive decline we
have seen in the Caribbean and other individual places is about to begin in
earnest in the rest of the world, and within a 2-3 decades the whole
world's reefs will look like the Caribbean or worse. I don't think that's
optimism. The future is very unlikely to be like the past, given climate
change's enormous threat and the world's pitifully inadequate response.
But the major thing I read from the graph, which I think is
unavoidable, is that the world's reefs have NOT seen a drastic decline,
like to 10% or less coral cover, like Florida and the Caribbean. I count
that as good news. Good news that may already be on the way to going the
way of massive forest fires in the US west, crippling droughts in
Australia, areas around the Persian Gulf very close to becoming
uninhabitable outside of air conditioned spaces, and more human deaths from
global warming now than any other weather cause. A terrible future for
coral reefs seems inevitable. The fact that nor all reefs, in fact the
majority of the world's reefs have not been devastated yet, is totally
separate from the future, when that is highly likely to happen. Go see a
healthy reef while there are still some left!!
2. Well, as I understand it, the entire eastern third of the US used to be
dominated by forests dominated by chestnut trees. We even have a Christmas
carol about "chestnuts roasting on the open fire" (they were edible and
abundant, but are no more). But chestnut blight basically killed them all,
100%. Stumps are able to put up shoots, but they don't get far before the
blight kills them. The eastern one third of the continent does indeed have
forests now, composed of other trees, so the forests are back, but chestnut
trees are not. (there are captive, protected chestnut trees and efforts to
breed resistance and the like) So essentially a very good analogy, except
the dominant species was essentially extirpated by disease and has been
more or less replaced.
I think I remember Terry Done long ago made the point that if most of
the corals on a reef are killed, the Acropora can recover quickly (weedy
species), but the big massive Porites colonies are hundreds of years old,
and cannot be replaced in our lifetimes, or perhaps the lifetimes of many
nations now existing (I just added that to what he said).
Point well taken. People have often said that coral cover isn't
everything, and that is right, might even be an understatement. So we
really need to take monitoring data that can reflect changes in species
composition. If we don't, we will miss this important aspect. I think it
is important. In the Caribbean and Hawaii, the diversity is low enough it
isn't hard to ID the common corals, and corals can be monitored at the
species level. They do that in Hawaii, I'm not sure if they do that in the
Caribbean, someone can fill us in on that. Much more difficult in the
Indo-Pacific. However, genera are much easier to ID than species, and it
is much easier to get a sample sufficient to see the trends of the more
common genera. That's all within the range of possibilities for the
Indo-Pacific, and we should gear up to do it, before the great devastation
of coral reefs starts happening to the many reefs that have not been badly
damaged yet. Because it is coming, as sure as the night follows the day.
We have enough time to get baselines, let's not blow it.
I rather doubt a large massive coral can re-sheet over most of the
colony, but maybe people with expertise on that can tell us. Would be
great if they could. I know that there is a literature on wound healing,
if I remember the larger the wound the slower the healing and the higher
chance it won't be complete, and most of that was done on wounds of several
cm sq, not meters sq.
Good point on the corals on the GBR. Death is permanent for the
individual involved. Point that I was making is that new colonies
obviously settled and grew, and coral cover has recovered on the GBR.
Something I've never read anybody rejoycing about. I think it is a good
thing. Thank heavens. But obviously, though they were resilient and
recovered coral cover, most likely the species composition has changed, the
species replacing are probably enriched in fast-growing weedy species that
are more vulnerable to bleaching and other disturbances. And in general,
the ability to recover is not unlimited. Bleaching events are coming more
and more often, and once they are close enough together, they will work as
a rachet (as Chuck Birkeland has often pointed out): massive mortality
followed by a few years of slow recovery beginning, not nearly recovered by
the time the next one hits, which takes it down further. Like going down a
set of stairs, and ending in near total loss of the ecosystem, algae beds
here we come, and many tears.
I'd add to your forest story: Nearly all chestnut trees in the US
east were killed, about 4 billion trees, within 40 years of the
1904 accidental introduction of the fungus. A few trees survive, where
there are no other trees within 10 km or more, spores are wind blown.
Wikipedia has a good article on it. Almost all people in the US alive now
have never seen a chestnut tree, and society has forgotten about them.
Other trees have grown in their place. North America has a whole series of
introduced organisms, many insects, which attack trees, Dutch Elm disease,
bark beetles, ash beetles, I can't turn around without another one, they
continue to be introduced. Battle is on to find ways to control them, the
alternative is to have one tree species after another devastated. And we
do need trees. Sounds similar to the coral disease story in the Caribbean,
though there is no evidence I know of, of the Caribbean coral diseases
being introduced.
But a good, thought-provoking analogy.
Cheers, Doug
On Fri, Feb 4, 2022 at 4:19 AM Ryan McMinds <mcmindsr at usf.edu> wrote:
> Alina captures my general reaction to your post, Doug, but I'd like to add
> that:
>
> 1) I don't see stability in that graph like you do. As you acknowledge,
> there has been a fairly steady decline since 2009, and the other data in
> the report (regarding surface temperatures and acidity) suggest that the
> last decade's downward trend will continue, rather than the flatter
> multi-decadal trend.
>
> 2) As I replied to you personally: If a forest burns down, and grass
> grows over the ashes within months to produce 100% 'plant cover', has the
> forest recovered? I seem to remember some previous discussion on the list
> and literature about how the unprecedented die-offs of the last decade have
> led to extreme reductions in diversity, regardless of total hard coral
> cover. If all that has grown back is a variety of weedy Acropora species,
> these reefs are less functional, and are not likely to last. As the
> Caribbean illustrates depressingly, low-diversity coral systems are highly
> vulnerable to epidemics of disease and other stressors. In other words,
> that current downward trend in coral cover is likely to accelerate even
> more in the near future, regardless of how resilient the replacement
> species are to bleaching. And to the first point, in terms of diversity, it
> may be perfectly reasonable to say that more than 50% of the GBR is still
> dead. What's there now isn't the same as what was there before.
>
> As an aside: I've used the analogy of coral reefs to forests a number of
> times when talking to non-experts, and I'm curious what people think of how
> good of a comparison it really is. Corals have been diversifying for about
> as long as all flowering plants, and provide structure like trees, so I've
> tried to drive home the scale of the 2016 GBR bleaching to people by
> asking: what they would think if 50% of the trees and flowering plants from
> Washington DC to Maine died in a blink? Would society have completely
> forgotten about it a year later? But, perhaps it is not fair to compare the
> relationship between Acropora and P. lobata to that between grasses and
> oaks. An oak can't just quickly regrow a new skin over a dead trunk,
> whereas a large reef-building coral could potentially. Maybe corals are the
> best of both weeds and trees, and there really is some optimistic take on
> their resilience (relative to similarly-scaled destruction in our familiar
> terrestrial ecosystems).
> ___________________________
> Dr. Ryan McMinds
> Research Assistant Professor
> University of South Florida
>
> On Feb 3, 2022, at 10:35 AM, Alina Szmant via Coral-List <
> coral-list at coral.aoml.noaa.gov> wrote:
>
> Hi Doug:
>
> I commend your hopeful enthusiasm, but as you imply in later parts of
> uour long post, I feel that your optimism is a victim to the shifting
> baseline. Those of us old enough to remember coral reefs in the 69s and
> 70s when there was little coral cover measurements taking place can attest
> to many (not all) reefs have upwards of 60% coral cover. Thus persistent
> 28-30 % cover is still a loss of 50% compared to near 'pristine' levels
> back when. Likely the more sensitive species are gone replaced by more
> tolerant ones. By still much less coral building 3-d structure than decades
> ago. Sadly my observations for the Caribbean area from Curacao to Florida
> Keys leaves no room for optimism. Many reefs are doqn to below 15% cover.
> It would be great if the much larger Indo-Pacific region is doing better.
>
> Alina
>
>
>
>
> Dr. Alina M. Szmant, CEO
> CISME Instruments LLC
>
>
>
> -------- Original message --------
> From: Douglas Fenner via Coral-List <coral-list at coral.aoml.noaa.gov>
> Date: 2/3/22 7:44 AM (GMT-05:00)
> To: Lauretta Burke <lb.was.here at gmail.com>
> Cc: coral list <coral-list at coral.aoml.noaa.gov>
> Subject: [Coral-List] what does this new analysis tell us???
>
> I want to start out by thanking Lauretta and everyone involved in this
> for all the time and effort that went into this. This is fantastic. I see
> that the graphs on average world coral cover and algae cover are based on
> the latest report from GCRMN (Global Coral Reef Monitoring Network) which
> it has a link to. They did the work in the Herculean task of putting
> together the vast number of sources of data into regional reports and into
> the world report. We owe them a debt of gratitude. To my knowledge, this
> is the very first time that anyone has produced from hard data, a graph of
> the trends of coral cover for the whole world as well as regions in the
> world. This is indeed FANTASTIC in my view.
> To find the graph in the report, first click on the link Lauretta gave
> for "Global Coral Reef Profile." Go down just a little bit to the "Table
> of Contents" on the right, and click on "coral reef condition." Some pink
> bars will jump up. Move down just a little and find "Live hard coral
> cover" on the left, and "live algae cover" on the right. Scroll down just
> a bit to the graphs for these two things. Pink on the left for the coral,
> and green on the right for algae.
> Here is where I have to compliment Lauretta and the team there.
> Notice the axis on the left, down at the bottom is 0% cover. This is the
> way it should be graphed, because it allows the reader to see the relative
> magnitude of the changes. The original graph in the GCRMN Status report I
> found truncated that axis, the axis only goes down to 25%. That magnifies
> the variation in the graph. If you want to see the GCRMN report, just
> click the black disc with the exclamation point to the right of the title,
> and that opens an explanation, scroll down to the end and there is the link
> to the GCRMN report, and click on it and it will open up in a separate
> window. You have many sub-reports to choose from and browse through.
> Easiest to see the graph is to click on the executive report. The graph is
> on page 17.
> Now a question, what is the biggest, most general thing the graph
> shows?? I think that's best seen in the graph that is in the Resource
> Watch report Lauretta pointed to. What I see is stability!!! What???
> Aren't most of the world's coral reefs badly degraded or even dead???
> Shouldn't it show drastic decline??? Not according to this graph based on
> something like 12,000 data sets from all over the world. HUH??? Oh, there
> is some decline, indeed. But look at the size of the decline. Down from
> about 33.5% to 30% in the first decline, and 28% in the second. Does that
> fit with the impression we get from various published papers and the
> media?? How many media reports have said that half the coral on the Great
> Barrier Reef are dead??? I don't remember the exact terminology they
> used. If they said "have died," well that's true. Look at the AIMS
> monitoring data, the most recent version of it. I'll give the link below.
> Yes, half of the corals died, but amazingly, and contrary to all
> expectations I would suggest, coral cover completely recovered!!! (isn't
> that the definition of "resilient"?) I've pointed this out before, not a
> single person posted a response on coral-list and not a single person sent
> me an email about it. Not one. Huh???
> OK, now with a straight face, tell me that the world's coral reefs
> are dead or dying. Tell me that half the corals on the Great Barrier Reef
> are dead. They aren't any more!
> Please, tell me is this good news or bad??? Surely it is good news
> for coral reefs. So why aren't people celebrating??? Why aren't there
> "the corals aren't all dead" parties going on all over the world? Where is
> the confetti, the balloons, the silly hats and the noise makers?? Don't we
> want the reefs to survive? Surely it isn't because no one cares,
> scientists have been crying in their masks looking at dead reefs.
> Don't get me wrong, there is no evidence that all that mountain of
> reports and evidence of individual reefs being mostly dead and the
> Caribbean having had a huge decline in corals are wrong. None whatsoever.
> I trust every one of them. The El Nino in the Indian Ocean killed about
> half the coral there over the whole ocean. Some reefs like Chagos had
> about 90% of their corals killed. There are published pictures showing
> it. It is beyond discussion, it was real. But notice, some of those reefs
> recovered. When I got to go to Chagos in 2014 I think it was, there was
> lots of coral. If I didn't know the history, I would not have suspected
> that 90% of the corals had been killed. And of course the more recent
> bleaching years have done it again in Chagos. My fingers are crossed that
> the corals recover again. Maybe they will, maybe they won't. Scary!
> Anyone can ask, "how many times can they recover?" As these events happen
> more often as the world warms, when will they happen so often the corals
> can't recover? That time is coming whether we like it or not, and will be
> here sooner than any of us want. We're sitting on the railroad tracks as
> the train approaches going full blast.
> OK, there are lots more things to discuss and figure out. For one,
> is 35% cover "high" cover??? Not in my book. The Eddy et al paper
> reported that scientists who saw reefs before the decline began estimated
> from memory coral cover of 58 or 59%. That is a LOT higher than 35%. I
> notice that there is no hint of decline early on in this graph. So that's
> a puzzle. Some people have even thought that originally coral reefs had
> near 100% coral cover. 35% is a LONG ways from that.
> Coral monitoring data is NOT perfect. BUT, in the absence of any
> other hard data on coral cover in the past, isn't this the "best available
> scientific evidence?" The "best available scientific evidence" is often
> quoted as the best standard for management. Why?? Wouldn't "perfect"
> evidence be better?? Sure, everybody knows that. But we NEVER have that.
> If we wait for perfect evidence to manage anything, we will never manage
> anything, and we'll lose the resource. That's why it was adopted for
> fisheries management (though all too often probably not followed). Science
> is progress, rarely if ever perfection or final proof. Always subject to
> improvement in the future.
> So I will state that I think this graph is now the "best available
> scientific evidence" on the trends and status of coral reefs around the
> world. Anybody can take a shot at showing me wrong. Might be good if
> people did.
> For one thing, the methods used to get to such graphs are not very
> transparent to us average nobodys (I'm talking about myself!) who are not
> experts in statistics and methods for doing this sort of thing. I'll point
> out one major problem I've never seen addressed. And that is that coral
> reefs are famously "patchy." Stated differently, they have high spatial
> variation over a wide range of scales. If you want to detect change, you
> need to hold other variables constant, particularly ones that are powerful
> and could produce large artifacts. Spatial differences are one such
> variable for monitoring. If someone takes data on coral cover at one
> location one year and a different location at a later time, and claims that
> the corals have gone down or up, does the data support that conclusion???
> Well, strictly speaking, NO. Except during powerful disturbances, coral
> change over time tends to be gradual, growth is gradual and slow. Spatial
> difference can be huge. One spot has near 100% coral, another is nearly
> all sand, and on and on. Now for these big studies, they have to combine
> data from many different locations, and it is a good assumption that the
> different locations have different coral cover at the same time. By
> "locations" I mean everything from transect sites to islands or reefs to
> archipelagoes. It is common, even typical, for monitoring programs to
> start, run for a while, then stop, maybe restart. Combine lots of records
> from different places, when there are differences between locations, and
> there are gaps of missing data from particular sites in some years, and for
> reefs or islands or even archipelagos, all at different times. How do
> people doing these things balance those things out to minimize the
> artifacts due to spatial location and get only signal from changes in
> time??? Ideally, every location would have data for the entire time
> period. We KNOW that is NOT true, there is very little early data and
> mountains of late data. What if the locations for early and late are
> different?? They HAVE to be different. OK, I'm NOT saying that the
> analyses have no way to pull the temporal signal out and throw away the
> spatial signal. I just don't know how they do it, or even whether they do
> it at all. Often methods sections are very densely written and someone who
> isn't an expert on the exact thing the paper is about could never replicate
> the paper. All too often.
> So OK, I confess to raising a lot more issues than I can address, but
> maybe someone can do that for us.
> The bigger picture, however, is that there is a clear conflict
> between what this data shows, and what we have been saying. There is no
> conflict between what has been reported before, destruction of coral has
> surely occurred everywhere it has been reported. BUT, BUT, no one has seen
> all the world's reefs. Our monitoring sites are not chosen in a random
> fashion across archipelagoes, islands, or reefs, even if they are within
> reefs. It is too late to change that for data from the past. But at least
> shouldn't we acknowledge it? Our monitored reefs may be unrepresentative
> of the world's reefs. Maybe. The first report of a huge decline that I
> know of was Terry Hughes' report of the decline in Jamaica after Hurricane
> Allen and the die off of Diadema. As subsequent analyses were done, the
> decline in other Caribbean reefs was not so bad. Then analysis of the
> Pacific reported less decline than the Caribbean (so Jamaica decline was
> real, but not completely representative). The Indian O certainly got hit
> hard by the 1998 El Nino mass bleaching, but some recovered. Now this
> analysis reports an amazingly small amount of coral decline when you look
> at the world as a whole. That implies that there are a lot of reefs that
> have not declined.
> Shouldn't we be celebrating? I have to admit, that I'm very
> suspicious that people are disappointed that it doesn't show the death of
> the world's coral reefs. But notice, this has nothing to do with the
> predictions of the upcoming decimation of coral reefs, nor the many reports
> of many individual reefs having experienced mass mortalities. All those
> are real. There are just a lot of reefs that haven't yet had bad declines.
> I think this new graph is the "best available scientific evidence"
> now, until we get better. I think we need to change our tune, and
> celebrate a little (even though this does NOT mean that we humans saved the
> reefs, rather simply that we haven't killed them all YET.) We are blessed
> with more coral in the world than we thought we had. That's GOOD NEWS!
> (no denying it won't last, though!!)
>
> In summary, I'd like to paraphrase Mark Twain. When a newspaper reported
> he had died, he said "My death has been greatly exaggerated." Clever guy.
> Of course later he did pass away.
>
> So I'll paraphrase him: "The deaths of the world's coral reefs has been
> greatly exaggerated." Anybody care to argue otherwise?? (I actually would
> welcome that, I think it needs to be discussed and NOT IGNORED.)
>
> Personally, I think we need to make our statements, especially to the
> press, so that they fit with the actual "best available scientific
> evidence" the best we can. If we cry "wolf" too many times and there is no
> wolf, and then when there really is a wolf, nobody may come to help, and
> the reefs will be in even worse trouble. No??
>
> Cheers, Doug
>
> Eddy, T. D., Cheung, W. L., and Bruno, J. F. 2018. Historical baselines of
> coral cover on tropical reefs as estimated by expert opinion. PeerJ 6:
> e4308
>
>
> The AIMS most recent monitoring report:
>
> https://www.aims.gov.au/reef-monitoring/gbr-condition-summary-2020-2021
> Scroll way down for the graphs for the northern, central, and southern
> Great Barrier Reef. See the huge declines and the amazing recovery.
>
> On Fri, Jan 28, 2022 at 10:40 AM Lauretta Burke via Coral-List <
> coral-list at coral.aoml.noaa.gov> wrote:
>
> The World Resources Institute
> <
>
> https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.wri.org%2F&data=04%7C01%7CLauretta.Burke%40wri.org%7C8ddf465f154a47ab0dae08d9e299a1d3%7C476bac1f36b24ad98699cda6bad1f862%7C0%7C0%7C637789971762899865%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=y6jbaqL74YGSqFtABvZ8%2BTXHvL4viuHMvOqcUzU15nA%3D&reserved=0
>
>
> and partners have developed a *Global Coral Reef Profile*
> <
>
> https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fresourcewatch.org%2Fdashboards%2Fcoral-reefs&data=04%7C01%7CLauretta.Burke%40wri.org%7C8ddf465f154a47ab0dae08d9e299a1d3%7C476bac1f36b24ad98699cda6bad1f862%7C0%7C0%7C637789971762899865%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=cqV65BjexngQp%2FQfpbPfGUfTqEdzS3rSifOaSidngGo%3D&reserved=0
>
>
> and ten regional dashboards
> <
>
> https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fresourcewatch.org%2Fdashboards%2Fcoral-reef-dashboards&data=04%7C01%7CLauretta.Burke%40wri.org%7C8ddf465f154a47ab0dae08d9e299a1d3%7C476bac1f36b24ad98699cda6bad1f862%7C0%7C0%7C637789971762899865%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=q8M2cAkxUkhTqPK51p4ph6NvLoM1Ur3h3Me%2BAIBlUZA%3D&reserved=0
>
>
> which provide an overview of the world’s coral reefs including
> consolidated, map-based information and indicators on the value of coral
> reefs, the threats they are facing, the factors which promote coral
> resilience, progress on protecting reefs, and what actions are needed to
> save them.
>
> The dashboards integrate information from the Global Coral Reef Monitoring
> Network, NOAA Coral Reef Watch, Mapping Ocean Wealth, UNEP, Global Mangrove
> Watch, Protect Planet / World Database on Protected Areas, MPAtlas, 50
> Reefs, and data on local threats to coral reefs, including water quality.
> The maps and indicators provide links to all the original data sources and
> data providers.
>
> See https://resourcewatch.org/dashboards/coral-reef-dashboards
> <
>
> https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fresourcewatch.org%2Fdashboards%2Fcoral-reef-dashboards&data=04%7C01%7CLauretta.Burke%40wri.org%7C8ddf465f154a47ab0dae08d9e299a1d3%7C476bac1f36b24ad98699cda6bad1f862%7C0%7C0%7C637789971762899865%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=q8M2cAkxUkhTqPK51p4ph6NvLoM1Ur3h3Me%2BAIBlUZA%3D&reserved=0
>
>
> for access to all.
>
> Please send me any comments.
>
> Best,
>
> Lauretta Burke (lauretta at wri.org)
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