[Coral-List] Mixed Messages

Risk, Michael riskmj at mcmaster.ca
Wed Jul 31 14:15:46 UTC 2019


Too long.

I would remind -listers that there have been (as far as I know) only two studies of what happens to a reef when the water is cleaned up: Kaneohe Bay Hawaii, and Worthing Barbados. In both cases, recovery surely an aspect of "resilience") was rapid.

The interesting (and depressing) aspect of this is, why has the coral reef biological community been so slow to accept the impacts of land-based stresses? The reluctance sometimes reaches heroic proportions. In previous discussion on this thread, when Steve asked how to reconcile the paper showing  bleaching on the GBR and Brian's 30-year Looe Key work, some bright spark suggested that the GBR work covered a huge area, whereas Brian looked only at Looe Key. As though Looe Key were the only spot in the world's oceans where N enrichment has occurred. (And I point out that the monitoring on the GBR is incapable of detecting land-based stresses-see Reef Encounter, 1988.)

Due to a lot of foot-dragging, we have been deprived of a crucial experiment: how will healthy coral ecosystems survive global warming?

In 2002, Gardner et al showed us that the Caribbean had lost >1/2 its coral by 1980. Recent Florida efforts emphasize transplanting corals, without tackling WQ issues. Ten years ago I said (MPB Editorial):

"I will digress here a moment to lament the current state of coral
reef science politics. Somehow, we are led to believe that, out of
all the ecosystems on the planet, reefs are the ONLY ones not affected
by nutrients (Szmant, 2002). Some of this debate is no doubt
truly driven by responsible people going where the data lead, but a
cynic might note the confluence of development money and political
pressure with the willingness of suits to say it’s OK to dump/
dredge/clear/whatever, because it’s all grazing and overfishing."
From: Coral-List [coral-list-bounces at coral.aoml.noaa.gov] on behalf of Douglas Fenner via Coral-List [coral-list at coral.aoml.noaa.gov]
Sent: July 29, 2019 6:49 PM
To: Steve Mussman
Cc: coral list
Subject: Re: [Coral-List] Mixed Messages

     I think it is an open empirical question whether reducing local
impacts improves resilience.  One confusion may be due to the definition of
the word "resilience."  Some people have used "resilience" to mean both
resistance to being killed and ability to recover.  Others have used
"resistance" to refer to being killed and "resilience" to ability to
recover.  Might be an important distinction.  It could be that local
impacts have little or no effect on whether hot water kills corals or not.
Evidence is strong that if the water gets hot enough, they die even in
places with essentially no human local impacts (northern Great Barrier
Reef, Scott Reef in NW Australia, Chagos, Jarvis (remote US Pacific island)
etc).  Might be that local impacts have a huge effect on whether corals can
recover.  Nearly no local impacts and they recover (such as Scott Reef and
Chagos), and heavy impacts no recovery (Discovery Bay, Jamaica, 40 years
later).  Or maybe that's not the solution to the question, empirical
question, important question.
     My thought is that this title ("biggest threat to coral reefs") was on
the popular article, not on the original, scientific article, it is not the
fault of the authors of the scientific article unless they provided the
idea that poor water quality is the greatest threat to coral reefs to the
popular article writer (which I don't know to be the case, and I know that
popular article writers have to have an attention-grabbing title to pull
readers in, so I assume it was their idea).
      If the popular article had said that poor water quality was the
biggest threat to Florida reefs, that may well be true.  My impression was
that coral disease was the proximate cause of the death of most Florida
corals.  But as the writers of this scientific article point out, nutrients
have been documented to exacerbate coral diseases.  So maybe nutrients are
the ultimate cause of the Florida coral deaths.  And could well be same or
similar for the Caribbean, I suppose.  But for the world's coral reefs?  I
don't think so, especially threat ifor the future.  Mind you, the
documented decline in Florida and the Caribbean is greater than in most of
the Indo-Pacific.
      Nutrients are widely considered to be one of the greatest threats to
coral reefs.  Reducing nutrients from humans is obviously a very good thing
to do, vital in many places, particularly Florida.  No dispute there.  But
many of us think that global warming causing bleaching is the greatest
future threat to the world's corals as a whole.  At the same time, other,
local threats can have great impacts locally, and we must act on them as
well as climate change, and locally the local threats are about all
individuals can reduce.  But we must get global warming under control or
the world's corals are going to be mostly dead from bleaching if they
weren't already killed by disease, nutrients, sediment, overfishing, etc
etc etc.
     Cheers, Doug

On Mon, Jul 29, 2019 at 2:52 AM Steve via Coral-List <
coral-list at coral.aoml.noaa.gov> wrote:

> I’ve received a number of interesting responses to my inquiry and that
> leads me to attempt to clarify a few things. As far as points of contention
> in the two papers I cited, what I find most complexing are the somewhat
> incompatible references to the effects of water quality. One paper suggests
> that if water quality improved, resilience would be enhanced while the
> other points out that there was “no sign of bleaching protection where
> water quality was high”. While I’m sure that the dynamics can vary from one
> reef to another, this seems to be a critical point with universal
> implications. I wouldn’t be surprised if it were determined that every reef
> reacts somewhat differently to a whole host of what must be, at least to
> some extent, unique and asymmetrical threats.
> To be clear, I’m not suggesting that the waters are being muddied
> intentionally. The data should lead you wherever it does, but what I am
> implying is that we have to mindful of the fact that in today’s world
> swayed by sound bites and social media, even the most rigorous scientific
> findings can be spun, even unintentionally, by seemingly innocuous
> headlines like this:
> https://www.earth.com/video/poor-water-quality-may-be-the-biggest-threat-to-coral-reefs/
> Does it matter if water quality, plastic pollution or sunscreens are hyped
> intermittently as the greatest threat to coral reefs? Maybe yes, maybe no,
> but I do know how hard it is to break through on climate change. Right now
> my concern is that just when we seem to be gaining traction on perhaps the
> most challenging of issues I react with trepidation to anything that could
> cause even delusory momentum headed in the right direction to suddenly slip
> away.
> Steve
> Sent from my iPad
> _______________________________________________
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> Coral-List at coral.aoml.noaa.gov
> https://coral.aoml.noaa.gov/mailman/listinfo/coral-list

Douglas Fenner
Ocean Associates, Inc. Contractor
NOAA Fisheries Service
Pacific Islands Regional Office
PO Box 7390
Pago Pago, American Samoa 96799  USA

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