[Coral-List] diver distance

Martin Moe martin_moe at yahoo.com
Thu Aug 15 14:59:41 EDT 2013

I would like to add something to this thread. The discussions
have morphed from the potential of damage from unknowing divers into lamentations
on the declining condition of our coral reefs from natural as well as
anthropomorphic causation. Maybe in some places we can repair some of the
damage. I’m a member of the Sanctuary Advisory Council for the Florida Keys
National Marine Sanctuary and the SAC and the Sanctuary are working on how we
can protect, maintain and actually restore the coral reefs of the Florida Keys.
The focus of the current rezoning work of the FKNMS and the SAC is on how we
can preserve and restore our marine ecosystems. We are in the early stages
developing a plan for the aggressive protection and active restoration of our ecosystems.
We don’t have all the answers yet, but things are falling into place. We are carefully
examining what we can do and where we can do it.
We are working to achieve marine ecosystem restoration
through three basic methodologies.
1/ Review of our already established marine protected zones
and establishment of additional marine protected, no-take zones that contain
all the elements of a healthy tropical environment; reef, rubble, sand, and
seagrass, at various depths as marked and enforced marine protected, no-take
areas where all species of marine life can attain a natural balance and natural
productivity. Human activity, in ways known and unknown, can disrupt and effect
behavior and survival of many species that are not the target of the activity.
Zones where the touch of the human hand is light and infrequent allows these
areas to maintain a natural ecology and to serve as seed banks for the broader
region. A case in point is the remarkable recovery and expansion of fish
populations in the marine protected area of the Dry Tortugas in the span of
just 5 years. (Implementing the Dry Tortugas National Park Research Natural
Area Science Plan, The 5-Year Report; 2012). 
 2/ However, our
economy is also important and some of these marine protected areas will use
regulation, enforcement, education, and outreach to restore, protect, and
maintain as best a natural ecology as possible while still allowing for
responsible economic use of these natural resources. This includes active
management of fishery resources in open zones to protect as best as possible
the natural ecology of exploited species, such as game fish, food fish and
invertebrates, and the structure and health of coral reefs.
 3/ Create the
management and economic structure that will stimulate active restoration of
coral reef structure, sea grass, and keystone species that are essential to the
restoration of the ecology and ecosystems of the Florida Keys. Much of current
ecosystem restoration is a new science that is currently being developed and
shows great promise for restoring environmentally resilient strains of keystone
species of coral reef organisms. It is an emerging technology that requires
scientific development and flexibility of regulation to allow timely and
effective experimentation and application of restoration science.
On this last point, great progress has been made by Ken
Nedimyer, (Coral Restoration Foundation), The Nature Conservancy, Mote Marine
Laboratory Center for Coral Reef Research, and other organizations over the
last 10 years in the propagation of resilient strains of Acropora and other
coral species; and in the outplanting of these strains on our reefs. These efforts have been successful to the point that spawning of the corals that have grown into thickets of reestablished
coral colonies has actually occurred.
However, with the realization that reestablishment of coral
colonies without efforts to control pollution from human waste and without
efforts to restore the ecological environment that allows Atlantic coral reefs to
maintain a functional coral reef ecosystem, we are doing the following. Ever
since the establishment of human populations on the Florida Keys, the methodology
for disposing of human waste and household liquid waste has been first cesspits
and secondly septic systems. Due to the very porous nature of the limestone
rock base of the Keys, the nutrients, bacteria, viruses, and chemical contaminants
quickly find their way in to the canals, near shore waters, and even to some
degree to the offshore coral reefs. We have made great and expensive progress
in construction of sewer systems in the Keys over the last few years, and this process will be
completed throughout the Keys within two or three years.
Another critical effort to restore the coral reef ecosystems
of the Florida coral reefs involves reestablishment of the critical function of
herbivory to our reefs. As everyone involved in the study of western Atlantic
coral reefs is well aware, the advent of a decimating disease in 1983 destroyed
the billions of long-spined sea urchin, Diadema
antillarum, that populated the hard bottoms of this vast region and effectively
eliminated the function of herbivory on the coral reefs. Not only did Diadema control macro algal growth to
the extent that corals can effectively compete with macro algae for space and
light, the feeding activity of Diadema also cleans substrates down to a hard surface, which stimulates the growth of
crustose coralline algae.This hard
surface allows settlement and survival of coral larvae, Diadema larvae and many other invertebrates as well. Ecological
restoration of Florida’s coral reefs will not be possible without the return of Diadema to these reefs.
It was thought that Diadema should return to the reefs within a short time, despite the 94 to 98 percent mortality,
because they are extremely fecund. An adult female can produce between 10 to 20
million eggs per spawn and can spawn many times each year. But thirty years
later the return of Diadema to Caribbean
reefs is small and patchy and their return to the Florida reefs is represented by
scattered individuals and very occasional small groups. Reasons for the lack of re-population includes low numbers of larvae in the waters of the region and
rapid overgrowth of macro algae on reefs and hard bottoms. Numbers of Diadema larvae in the plankton pre 1983
must have been immense before the pandemic and their loss may have actually
changed plankton ecology in this region. The rapid shift on the reefs from
coral domination to macro algae domination changed the benthic ecology as well.
Macro algae all but eliminated exposed hard surfaces, collected a depth of
sediment on these bottoms, and harbored an increased number of micro predators
that further reduced the numbers of newly settled Diadema juveniles. Thus although Diadema are present on Florida reefs, their numbers are so low that
they are ecologically extinct.
With large scale culture of Diadema through the larval stage into juveniles, it may well be
possible to restore them to the reefs. If ecologically effective populations of Diadema can be established on selected
coral reefs along the Florida reef track, and if these populations are maintained at ecologically
functional numbers through artificial recruitment in place of ineffective
natural recruitment; then there will be coral reef areas where corals can grow
and reproduce under the conditions of natural herbivory and Diadema can also grow and condition the
hard substrates for settlement and survival of corals, Diadema and other invertebrates. Also under these conditions, Diadema can spawn in the close proximity
to each other that allows for fertilization of the immense number of eggs
produced by adult females. Settlement and survival of corals and Diadema will increase, and over time,
the ecologically restored coral reef areas will grow in size, and with the
increase in larval numbers, new areas of coral and Diadema establishment will
This depends, of course, on the development and
establishment of the technology and facilities for large scale culture of Diadema, and I don’t think that the possibility
of this is very far off. The Mote Center for Coral Reef Research under Dr.
David Vaughan, in addition to a number of coral restoration projects, and
myself in a small home based lab, have been working on developing the technology
for Diadema culture for several
years. It is a very difficult task but we have both been able to rear hundreds
of Diadema into the stable juvenile
stage. I have reared them to adults, spawned the hatchery bred adults, and
reared the F2 generation to stable juveniles. (A “stable” juvenile is feeding
and growing to 1 to 2 cm in test diameter.) For coral reef restoration work,
however, we have to be able to consistently rear thousands of juveniles that
are behaviorally capable of survival on coral reefs at least as well as
naturally settled juveniles. We still have a way to go on very limited funding
before we will have accomplished this goal. 
It is a difficult task but the future of Florida’s reefs
depends on the merger of the coral and Diadema restoration technology. This is not an impossible dream. David Cohen, director
of the Sea Urchin Hatchery in Honolulu, has been working with a different sea
urchin. Tripneustes gratilla, to control macro algae in
Kaneohe Bay and just recently announced that over 100,000 urchins have been
released since January of 2011. Hopefully in the not too distant future Florida’s
reefs will benefit from a similar program. We will never know if ecological
restoration of Florida’s coral reefs is possible if we don’t make a serious
effort to restore Diadema.
Martin Moe

 From: Steve Mussman <sealab at earthlink.net>
To: Eugene Shinn <eugeneshinn at mail.usf.edu>; "coral-list at coral.aoml.noaa.gov" <coral-list at coral.aoml.noaa.gov> 
Sent: Thursday, August 15, 2013 9:15 AM
Subject: Re: [Coral-List] diver distance

Dear Gene,

Yes, in the long term (over geological time) nature has likely been more harmful to coral reefs and other ecosystems than humans. But then consider the fact that we humans haven't been here but for a small fraction of earth's existence and the proposition turns.

We really haven't had much time to over-fish, litter, chemically pollute, cut down mangroves and dump unhealthy levels of nutrients and sedimentation into our coastal waters. And don't forget we haven't been exposing those scores of happy snorkelers and divers to the wonders of what used to be thriving reefs but for a few fleeting seconds of earth's time.

So while oodles of money are flowing and the Keys economy is the best you have ever seen, have you ever stopped to consider the picture that is emerging for future generations to behold?   What will that ever popular Molasses Reef look like three decades from now? 

Maybe I'm just not finding enough comfort in the fact that nature can be harmful too. 


-----Original Message-----
>From: Eugene Shinn <eugeneshinn at mail.usf.edu>
>Sent: Aug 14, 2013 4:51 PM
>To: "coral-list at coral.aoml.noaa.gov" <coral-list at coral.aoml.noaa.gov>
>Subject: [Coral-List] diver distance
>Dear Listers, I just spent more than a month diving in the Keys and 
>photographing the corals I have photographed yearly since 1960. Un 
>fortunately there has been no noticeable improvement at those sites 
>(Grecian Rocks and Carysfort Reef). Have spent last few days catching up 
>on e-mail and scanning the various coral list threads. As a geologist it 
>was easy to identify with the comments by Dennis Hubbard. His Caribbean 
>work indicates a coral growth hiatus at 3,000 and 6,000 years bp (before 
>present). In the Keys we have documented a hiatus in /Acropora 
>cervicornis/ growth centered around 3000 years bp as well as one 
>centered at 4,500 ka. The 6 ka hiatus found by Hubbard is not present in 
>Florida Keys reefs because the shelf was being flooded and corals were 
>just beginning to grow at that time. This knowledge is based on Carbon 
>14 dating of corals at the base of coral reef cores. Although dating 
>verifies two major breaks in coral growth there were likely many more 
>during the past 6 ka (thousand years) when the so-called Florida reef 
>tract was being flooded during the world-wide Holocene rise. Frequent 
>waxing and waning occurred during that time because approximately 98 
>percent of that 150+ mile long reef tract has built up no more than 2 m 
>of coral accumulation. That knowledge is based on more than 20 years of 
>high resolution seismic profiling and ground truth coring 
><http://pubs.usgs.gov/pp/2007/1751>. In fact, a core adjacent to the 
>Aquarius habitat revealed only 15 cm of accumulation during the past 6 
>ka. In other words biologists studying that area have in fact have been 
>studying a hardground community that looks like a coral reef. That's ok 
>because they would get the same biological results studying corals etc. 
>on a true coral reef accumulation.
>True reef accumulations do occur in the keys but they are mainly in the 
>form of coral spurs and occur mainly on preexisting Pleistocene bedrock 
>highs. These are the named reefs that have kept pace with sea level rise 
>(about 2 percent of the reef tract). It is the cores of these 
>accumulations upon which our knowledge of Keys coral reef history is 
>based. Clearly there were climate related events (increased hurricanes? 
>fluxes of cold water? warming seas? diseases?) that kept the other 98 
>percent of the reef tract from developing along with those on the 
>bedrock highs.
>Yes, People have likely affected growth in the past 50-years but that 
>does not prove natural events were not equally harmful. In the long 
>term, as Hubbard says, nature has likely been more harmful than people.
>During this latest expedition I observed formidable examples of shifting 
>baselines or should we now call it the "new normal"? During our short 
>visit to Grecian Rocks we observed the arrival and departure of at least 
>5 large catamarans each of which disgorged 20 to 30 snorkelers, not 
>including the numerous private boatloads of snorkelers.. I estimate that 
>around 200 swimmers snorkeled the leeward side of Grecian Rocks during 
>that day, and this was not even a weekend! I can only surmise that the 
>snorkelers were happy with what used to be a thriving reef and clearly 
>oodles of money was flowing into the Keys economy. After observing all 
>this activity the question of how close a diver should approach corals 
>seems moot. If the water is clear the divers appear to be happy and the 
>keys economy is flourishing like I have never seen during my 60 some odd 
>years of diving there. I wonder what it was like at the really popular 
>reefs such as Molasses reef?Gene
>No Rocks, No Water, No Ecosystem (EAS)
>------------------------------------ -----------------------------------
>E. A. Shinn, Courtesy Professor
>University of South Florida
>College of Marine Science Room 221A
>140 Seventh Avenue South
>St. Petersburg, FL 33701
><eugeneshinn at mail.usf.edu>
>Tel 727 553-1158
>---------------------------------- -----------------------------------
>Coral-List mailing list
>Coral-List at coral.aoml.noaa.gov

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