[Coral-List] Artificial Reefs

Dennis Hubbard dennis.hubbard at oberlin.edu
Fri Oct 18 09:46:22 EDT 2013


Thomas:

I disagree with your assessment at my core. However, a satisfactory
response will take more time than I have right now, so watch this space.

Dennis


On Fri, Oct 18, 2013 at 4:03 AM, Thomas Le Berre <thomas at seamarc.com> wrote:

> Dear Dennis Hubbard,
>
>
>
> Thanks for sharing your experience of your past restoration success. I fail
> to understand why you now seem to be considering this effort as a youth
> mistake. I agree with you that any types of structure will attract fish (in
> fact I even saw recently an exhibit at the Monterey Bay Aquarium where fish
> inhabit different pieces of junk on the bottom of the tank, which I thought
> was quite daring). I also agree that there may be a lot of things we don't
> know about the impacts of the artificial reefs. But I would also say that
> there is a lot of things that we do know and observe. You empirically
> determined the physical effects your rocks were having on wave propagation
> currents etc. and adapted to achieve what seems to be a desirable result.
> Physical effects are of course more direct to observe than ecological ones,
> and even though in time they may alter considerably an area (large events
> etc.), a good balance seem to have been restored through luck or skill.
>
>
>
> Change in the ecological factors of course take longer to be felt, but it
> seems that 20 years after, there were more fish and more corals. I would
> think that there is a necessary spill-over effect, more fish, more corals,
> more larvae, etc.(and if this is used for tourism purpose and not fished,
> that's again a bonus I guess). I won't go into whether fish were attracted
> or recruited to your structures. I have seen both depending on sites and
> species. Anyway, we will agree that on the ecological point of view, your
> project was also beneficial and certainly that the situation now is better
> than what is was before you started your project (or at least that any
> decrease in diversity, productivity cannot be assigned to that activity,
> but
> maybe global changes or other "unknown factors").
>
>
>
> Having been successfully through a major storm, we could also say that the
> area is more resilient and adapted to climate change. (The storm on the
> dump
> would definitely have been a disaster). In addition, there is a better
> recreational value, possibly keeping the crowds away from the natural reef.
>
>
>
> What other major unknown factors could there have been that would condemn
> your project?
>
>
>
> Now, imagine that this project didn't occur, do you think this would have
> prevented the developer to do whatever to try and improve their situation,
> regain a beach etc.probably given it to a contractor with no feeling
> whatsoever for the marine life (yes, this is almost always the case), cheap
> and easy, but which would constant recurring works and meddling with the
> environment, never letting it settle, etc... In developed countries maybe
> the legislation prevents developers to take the situations into their own
> hands without the necessary guidance and knowledge, but in many places,
> trial and error prevails.and the ecological side of things is always
> disregarded.
>
>
>
> At the stage we are at, I am wondering if the shortsightedness would not be
> to deny this reality, acknowledge "their" shortsightedness as a fact. We
> need to develop better solutions to the problems caused by coastal
> developments. Of course: there will be more people, there will be more
> tourists, there will be more pressure to have more infrastructure. I don't
> believe that wisdom will suddenly sink in politicians brains overnight, and
> even then they all have their crowd of voters to please. Yes, it may be
> that
> not only your project, but the human race as a whole is doomed to failure
> at
> the start, and yes, we are going to have to display last minute (in
> geological terms) reactions to the discovery of petrol engines and
> penicillin. I would say that this is more tragic than pathetic.
>
>
>
> Minor successes after minor successes is already going forward. And it does
> develop a know-how that can be shared, developed etc... It eventually
> develops an economy and more environmentally minded people can find related
> jobs and help change the present dynamic. I can think of many people
> educated in marine fields not finding any opportunities to work, what a
> waste of possible effort. If there is more employment in the sector, surely
> all the associated research funding will grow as well.Right now, I feel
> that
> taking a refuge behind the "unknown factors" is the root cause for many
> bank
> funded developments to altogether do nothing at all for the ecology in
> coral
> reef areas, thereby saving dollars that would otherwise do very well into
> this part of the economy. Eager contractors are at times being discouraged
> to even think about it by local authorities as a result.
>
>
>
> Far from being a failure that you seem to be ashamed of, I feel your
> project
> should be a case study (and I am quite sure that you would love to have
> yearly monitoring data of the site). I don't question your verdict about
> your own work and accept your experience, but sincerely, I fail to be
> convinced that development of a practical know-how to successfully "meddle"
> with the ecological side of things during coastal developments needs to be
> altogether written off. In fact, I find it quite appealing and possibly
> necessary. Finally, I am wondering if the denegation of your own work and
> success story is the result of rational thinking and field observations or
> intense peer pressure.
>
>
>
> This is a long mail, thanks for reading this far.
>
>
>
> Best regards,
>
>
>
>
>
> Thomas Le Berre
>
> Managing director
>
> Seamarc Pvt. Ltd.
>
> www.reefscapers.com, www.marinesavers.com
>
>
>
>
>
>
>
> From: Dennis Hubbard <dennis.hubbard at oberlin.edu>
>
> Subject: Re: [Coral-List] Artificial Reefs
>
> To: "Rachel D'Silva" <rachdsilva at yahoo.com>
>
> Cc: "coral-list at coral.aoml.noaa.gov" <coral-list at coral.aoml.noaa.gov>
>
> Message-ID:
>
>       <CAFjCZNZP011hzEJDtrhr=fpQ7HiveuQQZPnkDcPTPqFnHXwoQA at mail.gmail.com>
>
> Content-Type: text/plain; charset=ISO-8859-1
>
>
>
> I think there are two extremes to this discussion. First, if you put ANY
>
> topographic structure on an open bottom, it will attract fish (they don't
>
> care - look at all the fish around those deep-water nuclear disposal
>
> sites). Also, corals will grow on it. However, the other side of the coin
>
> is that any structure you place into the environment will have some impact.
>
> Some of that will respond to the laws of physics (diffraction, diversion of
>
> flow, etc.) but much of it will respond to factors we largely do not
>
> understand. So the question is whether we should take the time to learn
>
> those factors so we can engineer the environment.
>
>
>
> About two decades ago, we placed ca. 100 rocks (5-7,000 lbs each) onto a
>
> terrace that had been the site of a flourishing *Acropora palmata* reef in
>
> the 60s (we didn't know this when we started the project). It had been
>
> killed not by disease but by dredge pipes that were raked across the reef
>
> to move sediment from the bay to cover the municipal dump for this island
>
> of St. Thomas (it was being decommissioned). Ironically, the owner of the
>
> dump who wanted to sell the land for development purposes was also the
>
> first director of the newly created Department of Conservation and Cultural
>
> Affairs (talk about irony.... and I can't lay out the half of it here).
>
> When we were called in, a huge hotel complex had just been built  and
>
> someone suddenly realized, "We have no beach!" This reflects a common
>
> development perception that the natural system can be engineered so all
>
> they have to do is throw money at a consultant like they do for financial
>
> issues.
>
>
>
> In this case, historical research revealed that this site had always had a
>
> wide beach and we could identify no realistic reason for it to not be there
>
> today. Further research into DPNR records revealed the bizarre situation I
>
> just laid out.... the reef had been mechanically destroyed and the loss of
>
> protection caused a wholesale exit of beach sand back into the hole).  We
>
> ultimately decided that, while we could not replace the biological
>
> function, we might replace the physical function by very carefully placing
>
> these large stones in a way that allowed wave energy to pas through (i.e.,
>
> it was not an impermeable structure but rather large boulders that broke up
>
> incoming waves and partially protected the shore). We also set it up so
>
> that strong unidirectional flow persisted behind the ridge (all that water
>
> coming in between the blocks had to exit - creatinf strong shore-parallel
>
> flow. The net result was that the new artificial beach persisted even after
>
> Hurricane Marilyn) and water quality remained acceptable behind the loosely
>
> scattered rocks. Our ultimate decisions on rock placement were based on
>
> climbing up on the hotel roof and looking at how the 10 rocks we'd placed
>
> each day affected wave refraction and diffraction patterns (very
>
> empirical). To keep them in place, e had 3-inch holes pre-drilled in the
>
> rocks and then pinned them to the bottom by drilling into the underlying
>
> substrate and inserting steel rods and marine cement into the rocks and the
>
> underlying substrate).
>
>
>
> When I visited the site years later, corals (even *Acropora palmata*) had
>
> colonized on the rocks - and the fish had moved in. The corals we had
>
> transplanted to the fron of thi area were still doing better than the
>
> natural ones nearby. This had become a reasonably popular snorkeling spot
>
> due to the easy access from the adjacent beach.
>
>
>
> Having set up this rosy scenario, I do not advocate the sense that physical
>
> structures are anything more than last-minute reactions to poor decisions
>
> in the past. While our structure created protection and made the hotel more
>
> viable, this was not a substitute for even a mediocre natural structure
>
> and, while the history of the area is amusing, it is also pathetic.I have
>
> always wondered how much these kinds of minor "successes" just feed the
>
> perceptions of developers that they can rely on the engineering/ecological
>
> community to come in and move things around a bit to cover their
>
> shortsightedness. I consider our project as one that was doomed to failure
>
> from the start even though the financial picture was improved and the
>
> ecological side was at least made no worse. I vowed to never do one of
>
> these projects again and can happily report that the slate is still clean.
>
>
>
> Dennis
>
>
>
>
>
> On Tue, Oct 1, 2013 at 3:54 PM, Rachel D'Silva <rachdsilva at yahoo.com>
> wrote:
>
>
>
> > Hey Coral List,
>
> > I'm looking for articles/papers with design and engineering options for
>
> > major functioning breakwaters (shallow) combined with reef restoration. I
>
> > like the idea of sections of the breakwater having a design component
> that
>
> > can be head started with coral fragments as well as functioning as a
>
> > potential dive/snorkel site. The standard designs and structures will
>
> > function as FADs...but in over fished waters.. this really isnt enough.
>
> >
>
> > I really appreciate any ideas/info you might have.
>
> >
>
> >
>
> > Rachel
>
> > 'Unless someone like you cares a whole awful lot, nothing is going to get
>
> > better. It's not'.- The Lorax
>
> >
>
> >
>
> > ________________________________
>
> > _______________________________________________
>
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>
> > Coral-List at coral.aoml.noaa.gov
>
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>
> >
>
>
>
>
>
>
>
> --
>
> Dennis Hubbard
>
> Chair, Dept of Geology-Oberlin College Oberlin OH 44074
>
> (440) 775-8346
>
>
>
> * "When you get on the wrong train.... every stop is the wrong stop"*
>
>  Benjamin Stein: "*Ludes, A Ballad of the Drug and the Dream*"
>
>
>
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>



-- 
Dennis Hubbard
Chair, Dept of Geology-Oberlin College Oberlin OH 44074
(440) 775-8346

* "When you get on the wrong train.... every stop is the wrong stop"*
 Benjamin Stein: "*Ludes, A Ballad of the Drug and the Dream*"


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