[Coral-List] ICRS 2021 meeting session: Can Coral Reef Restoration Increase Coastal Protection?

Storlazzi, Curt D cstorlazzi at usgs.gov
Fri Sep 11 18:16:37 UTC 2020


As to whether current restoration efforts are happening without first mitigating the stressors that caused the decline in the first place, I cannot speak to that overall.

I also cannot speak to coral breeding and/or engineering - I'll defer that to others that know what they're talking about. I think something we need to keep in mind with such breeding or engineering is thinking about what species to work on/with. I've traditionally seen a lot of work of A.cervicornis, but the geologic record shows that it's not a very hearty species (Chuck Birkeland gives a great seminar on this), and more recent studies by Lauren Toth and others have shown that the coral assemblages we currently see or saw in the past few decades on many reefs (and thus are often the targets to 'meet' for restoration) are not the coral assemblages that existed for the previous hundreds to thousands of years that actually formed the reefs. Some interesting things to think about....

But a number of us (USGS, NOAA, EPA, etc along with state, territorial, and local agencies) who make up the US Coral Reef Task Force are working to try to reduce both the global and local stressors to coral reefs to give the reefs and those restoration efforts a better chance of success. Do those efforts need more funding? I think one could ask, which of our (the coral reef community) efforts don't?

Great points and things I think we need to think about.

Happy Aloha Friday to all!


Curt D. Storlazzi, Ph.D.

U.S. Geological Survey
Pacific Coastal and Marine Science Center
2885 Mission Street
Santa Cruz, CA 95060
(831) 295-3429 cell during COVID-19


Message: 7
Date: Thu, 10 Sep 2020 12:24:14 -0400
From: sealab at earthlink.net
To: Storlazzi, Curt D via Coral-List  <coral-list at coral.aoml.noaa.gov>
Subject: Re: [Coral-List] Re: ICRS 2021 meeting session:
        Can Coral Reef Restoration Increase Coastal Protection?

Hi Curt,

I have a few questions regarding your response to Doug?s post.

>From what I can tell, most restoration/outplanting projects in existence have not waited for stressors to be mitigated before moving forward. (In fact, my concern is that many do not like to focus on addressing stressors at all).

You mention that in order for restorative efforts to have a good chance of success stressors need to be mitigated unless coral breeding/engineering has made the corals more resilient to those stressors?.

This is exactly the problem as I see it - is the plan to continuously genetically design corals to withstand ever increasing stressors?

I ask this because to me the lack of emphasis on addressing stressors only serves to reinforce the idea that we can engineer our way out of this - and that message only serves to delay the mitigation of stressors that natural coral reefs need to survive and flourish.

It seems to me that restoration has all the momentum for funding at the moment. Wouldn't it make more sense to allocate more of those funds towards mitigation until such a time that restoration and natural recovery have a more sustained opportunity to succeed?

Finally, I do mean to denigrate restoration efforts. Coral science is greatly enhanced by these projects, but in my humble opinion, some do a much better job than others. Those that do not (for whatever reason) emphasize causation are, in a sense, self-defeating and ultimately may even prove more harmful than beneficial to the end goal of saving coral reefs over the long run.


Steve Mussman

Sent from EarthLink Mobile mail

On 9/9/20, 10:27 PM, Storlazzi, Curt D via Coral-List <coral-list at coral.aoml.noaa.gov> wrote:


I whole-heartedly agree! Don't put canaries back in the coal mine. Thus one needs to determine what caused the coral decline in the first place, then that(those) stressor(s) need to be mitigated before any restoration likely has a good chance of success, unless coral breeding/engineering has made the corals more resilient to those stressors.

My thought regarding coral reefs and coastal protection is four-fold:

First, healthy coral reefs with high coral cover and rugosity (as would occur due to restoration) result in less wave-driven runup and thus coastal flooding. See Quataert et al. (2015).

Second, green coastal defense infrastructure is much less expensive than gray coastal defense infrastructure. See Ferrario et al. (2014).

Third, green coastal defense infrastructure such as coral reefs, oyster reefs, marshes, mangroves, etc can theoretically grow (not degrade as gray infrastructure such as seawalls and breakwaters do) through time if in a good environment, as discussed above, and generally are a net contributor to ecosystem health (as compared to gray infrastructure, which generally is not). See Beck et al. (2018).

Fourth, the US spends on the order of a few $million/year on coral reef restoration, versus on the order of half a $billion/year on pre-disaster coastal mitigation funding and 10s of $billions on post-disaster coastal restoration funding after hurricanes, such as Irma and Maria in 2017. If just a few percent of those pre-disaster mitigation funds or post-disaster restoration funds could be used for coral reef restoration, that would be a huge influx of funding for restoration. And that's just public dollars - what about private sector insurers? If a hotel restores its reef just offshore (reducing its flooding risk), might it get a lower insurance rate?

Thus if you can show coral reefs provide coastal protection at a management-relevant scale and in rigorously enough manner (e.g., Storlazzi et al., 2019), you might be able to create new funding opportunities for coral reef restoration to help increase ecological function, that, in turn, helps provide all of the other ecosystem services that average folks (non-coral lovers such as ourselves) crave, such as fisheries, tourism, recreation, etc.

Again, it does hinge, as you note, on successfully outplanting corals (maybe genetically engineered or selectively bred to be more resilient). But it seems we can't scale up those engineering, breeding, and outplanting efforts (and likely mitigation of local stressors such as land-based pollution) without a lot more funds that it appears are currently available....so let's think about how we might create such funding opportunities.

But that's just one thought....

Stay safe and sane in these crazy times, amigo.



Beck, MW, et al., 2018. "The global flood protection savings provided by coral reefs." Nature Communications 9:2186.
Ferrario, F, et al., 2014. ?The effectiveness of coral reefs for coastal hazard risk reduction and adaptation.? Nature Communications, 5:3794.
Quataert, E, et al., 2015. ?The influence of coral reefs and climate change on wave-driven flooding of tropical coastlines.? Geophysical Research Letters, 42: 6407-6415.
Storlazzi, CD, et al. 2019. "Rigorously valuing the role of U.S. coral reefs in coastal hazard risk reduction." USGS Open-File Report 2019-1027, doi.org/10.3133/ofr20191027.


Curt D. Storlazzi, Ph.D.
U.S. Geological Survey
Pacific Coastal and Marine Science Center
2885 Mission Street
Santa Cruz, CA 95060
(831) 295-3429 cell during COVID-19


From: Douglas Fenner
Sent: Wednesday, September 9, 2020 3:03 PM
To: Storlazzi, Curt D
Cc: coral-list at coral.aoml.noaa.gov
Subject: Re: [Coral-List] ICRS 2021 meeting session: Can Coral Reef Restoration Increase Coastal Protection?

Wouldn't an important aspect be how long improvements in the amount of live coral last?? If people plant out 10,000 corals and feel good about themselves, but only 100 survive more than 5 years, was it worth it?? This is a question which it seems to me the huge number of enthusiastic coral restoration people are dodging, and I think it is a critical one. Bad water quality and mass coral bleaching can undo all these good efforts, and WILL, if we don't address them, and so far we're failing miserably at that. Isn't this fad just rearranging the deck chairs on the Titanic??? Cheers, Doug

On Tue, Sep 8, 2020 at 7:05 AM Storlazzi, Curt D via Coral-List > wrote:

Dear colleagues:

We would like to draw your attention to a meeting session to address:

Can Coral Reef Restoration Increase Coastal Protection?

at the 2021 International Coral Reef Symposium, which is being held 18-23 July 2021 in Bremen, Germany.

If your work is relevant to this session please submit an abstract to ICRS20-39 under Theme 13: Interventions and Restoration via the following link:


Session Description:

Coastal flooding and erosion affects thousands of vulnerable coastal communities and has resulted in hundreds of billions of dollars in damage during the past decade alone; these impacts are predicted to worsen with continued population growth and climate change. There is growing recognition of the role of coral reefs in coastal hazard risk reduction as they dissipate wave energy and produce and trap sediment on adjacent beaches and thus reduce flooding and erosion. Given these benefits, there is the potential to apply coral reef restoration not only to meet ecological recovery goals such as coral species and reef communities, but also to reduce coastal hazards and build coastal resilience to current and future storms. To meet and support these joint objectives, there must be rigorous, quantitative assessments of restoration performance, particularly for risk reduction benefits. This mini-symposium focuses on advancements in understanding the role of coral reefs in hazard ris
 k reduct

ion, including but not limited to (i) quantifying the roles of coral spacing, morphology, and attachment strength in boundary-layer hydrodynamics; (ii) relating coral species morphology, structural complexity, or reef location to change in hydrodynamic roughness or induction of wave breaking for different environmental forcing conditions; (iii) design and siting of reef restoration to best reduce coastal flooding for different reef configurations; (iv) comparison of natural green and hybrid gray-green infrastructure in relation to ecological and hydrodynamic change; (v) incorporation of ecological connectivity into reef restoration site selection; and (vi) cost-benefit analyses of restoration for coastal hazard risk reduction. Summaries of current local or regional-scale studies, including modeling exercises are encouraged, especially if they evaluate social and economic impacts of different restoration options.

Please visit the conference website for more information:


Abstract submission closes 15 September 2020

For further information and all updates, please visit:


If you know of anyone who might be interested who might not receive this notice, please feel free to pass it along. We are very excited about this session and look forward to your participation. If you have any questions, please feel free to contact us. We hope to see you in Bremen!


Curt Storlazzi - USGS Pacific Coastal and Marine Science Center
Shay Viehman - NOAA National Centers for Coastal Ocean Science
Mike Beck - UCSC Institute of Marine Sciences


Curt D. Storlazzi, Ph.D.
U.S. Geological Survey
Pacific Coastal and Marine Science Center
2885 Mission Street
Santa Cruz, CA 95060
(831) 295-3429 cell during COVID-19


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