[Coral-List] Szmant 2002: Great review on nutrient enrichment on coral reefs (Gene Shinn)

Pawlik, Joseph pawlikj at uncw.edu
Tue May 8 08:51:49 EDT 2018


Hi Gene,

I’m glad you enjoyed your lecture from 3 decades ago!   For those who have not seen it:



https://youtu.be/LIbmsHmuxWk<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fyoutu.be%2FLIbmsHmuxWk&data=01%7C01%7Cpawlikj%40uncw.edu%7Ca7e1a11137be4743adb608d5b44bf940%7C2213678197534c75af2868a078871ebf%7C1&sdata=n%2BX1htIoDzpjp4Lxk6Jrc6KegDnjlorpmJ2nWed1j5c%3D&reserved=0>

The timing of Caribbean coral loss is really interesting relative to the hypotheses advanced to explain it, and the subsequent lack of Caribbean reef resilience. It seems pretty clear that novel (introduced) pathogens were involved and spread around the region, but the timing was much slower than for the diadema die-off, or the lionfish invasion, maybe suggesting multiple events with different pathogens (which would correspond to the multiple disease names that were proposed in succession).

Back to the nutrient issue, to my knowledge, only two hypotheses explain the region-wide lack of reef resilience because of a change in nutrient availability: the dust hypothesis (iron from dust enhances cyanobacterial N fixation) and the vicious circle hypothesis (seaweed proliferation on dead coral skeletons provides excess labile DOC that feeds sponges, which produce lots of N in close proximity to seaweeds).  Of these two, only the latter includes a mechanism for bypassing the uptake of N by water-column phytoplankton, which rapidly scavange available N, whether produced by anthropogenic sources or water-column cyanobacteria. The proximity of seaweeds and sponges closes that loop. Of course, these two are not mutually exclusive, and we included both in our recent paper on Caribbean reef resilience:
Pawlik, J.R., Burkepile, D.E., Vega Thurber, R. 2016. A vicious circle? Altered carbon and nutrient cycling may explain the low resilience of Caribbean coral reefs. BioScience, 66: 470-476 doi:10.1093/biosci/biw047.
http://people.uncw.edu/pawlikj/2016BioSciencePawlik.pdf

Regards,

Joe

**************************************************************
Joseph R. Pawlik
Frank Hawkins Kenan Distinguished Professor of Marine Biology
Dept. of Biology and Marine Biology
UNCW Center for Marine Science
5600 Marvin K Moss Lane
Wilmington, NC  28409
Office:(910)962-2377; Cell:(910)232-3579
Website: http://people.uncw.edu/pawlikj/index.html
PDFs: http://people.uncw.edu/pawlikj/pubs2.html
Video Channel: https://www.youtube.com/user/skndiver011
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From: Eugene Shinn <eugeneshinn at mail.usf.edu>
Sent: Monday, May 7, 2018 4:47 PM
To: Pawlik, Joseph <pawlikj at uncw.edu>; coral-list at coral.aoml.noaa.gov
Subject: Re: [Coral-List] Szmant 2002: Great review on nutrient enrichment on coral reefs (Gene Shinn)

Joe, I stand corrected. Thank you.  It is true the Acropora. cervicornis went first in 1983 while the palmata was still hanging on when these films were made in 1987. A few scattered colonies could still be found but the huge thickets were no more. It was really spooky seeing my self with black hair. Sadly that large brain coral near the Christ statue eventually died. It started dying at the top and then worked its way down. That head had appeared in several of Jerry Greenberg's well known underwater photographs. Thanks for the correction. Unfortunately the overall demise continues while many continue to monitor their demise. Gene
On 5/7/18 3:44 PM, Pawlik, Joseph wrote:
Thanks Gene,

I have no reason to doubt any of the points you make below, but the videos from 1987 clearly show high acroporid coral cover, with comments in the video narrative about the “recent” onset of coral diseases.  We began working on these sites 5 years later, and all this acroporid cover was gone.  So, maybe the beginning of the end began in the 1970s (as you indicate), but things dropped off a cliff in the late 1980s (at least in the northern Keys).

If Carysfort was gone by this time, why was N Dry Rocks and Grecian still OK?

Hard to argue with video evidence…

Joe

**************************************************************
Joseph R. Pawlik
Frank Hawkins Kenan Distinguished Professor of Marine Biology
Dept. of Biology and Marine Biology
UNCW Center for Marine Science
5600 Marvin K Moss Lane
Wilmington, NC  28409
Office:(910)962-2377; Cell:(910)232-3579
Website: http://people.uncw.edu/pawlikj/index.html<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fpeople.uncw.edu%2Fpawlikj%2Findex.html&data=01%7C01%7Cpawlikj%40uncw.edu%7C5a8d7858bf004d48873908d5b45bb15a%7C2213678197534c75af2868a078871ebf%7C1&sdata=MFazDv9sgWLYK%2BA2dp4HYGXcl%2F7NmoYqJAQsTUu0fH0%3D&reserved=0>
PDFs: http://people.uncw.edu/pawlikj/pubs2.html<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fpeople.uncw.edu%2Fpawlikj%2Fpubs2.html&data=01%7C01%7Cpawlikj%40uncw.edu%7C5a8d7858bf004d48873908d5b45bb15a%7C2213678197534c75af2868a078871ebf%7C1&sdata=O9w9eMmJsYw3u2RAzjOinr5ISnFkyiqv9xJZSR06N3Y%3D&reserved=0>
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From: Eugene Shinn <eugeneshinn at mail.usf.edu><mailto:eugeneshinn at mail.usf.edu>
Sent: Monday, May 7, 2018 2:55 PM
To: Pawlik, Joseph <pawlikj at uncw.edu><mailto:pawlikj at uncw.edu>; coral-list at coral.aoml.noaa.gov<mailto:coral-list at coral.aoml.noaa.gov>
Subject: Re: [Coral-List] Szmant 2002: Great review on nutrient enrichment on coral reefs (Gene Shinn)

Hi Joseph, Bleaching and black band disease did originate mainly in 1986 and 1987. However those were not the beginning of the end. The beginning of the end had started much earlier in the late 1970s. Harold Hudson, who was part of our USGS lab on Fisher Island, began using a siphoning device to remove black bands from large heads at Looe Key in 1986. He also made many measurement of the rate of BB spread, which was many cm per summer.
     I had begun taking annual photographs of a cervirornis and palmata at both Grecian rocks and Carysfort in1960.
Coral disease (not bleaching) began to be noticeable in the late 1970s. However the peak year of Acroporid death was 1983. The same thing happened at San Salvador as noted by the director and several researchers at the Finger Lakes research laboratory located there. As a result a nearby dive resort that catered to underwater photographers went bust and closed its doors. The principally A cervicornis reef (known locally as telephone pole reef) died over a period of about 3 months. I dove on the shallow reef in 1984 and the dead staghorn was still standing. I was with Phil Dustan at the time. Phil and I also visited a site off the north end of the island where there was a stand of large elkhorn corals. They were in growth position but entirely dead. About a year later I visited nearby Rum Cay with Bob Halley. All the Acroporids there were dead. Locals told us the Acroporids had died in 1983. If you check with old timers in the islands you will find it was true throughout the Caribbean. Of Course dive shop operators were not advertising that fact at the time. Not good for business.
    As you know I have continued to take annual photographs of the Grecian and Carysfort site until 2016. Coral demise has continued until the present. In the 1990s we began an extensive program of high-resolution mapping. The work was prepared by Barbara Lidz and can be read at https://pubs.usgs.gov/pp/2007/1751/<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpubs.usgs.gov%2Fpp%2F2007%2F1751%2F&data=01%7C01%7Cpawlikj%40uncw.edu%7Ca7e1a11137be4743adb608d5b44bf940%7C2213678197534c75af2868a078871ebf%7C1&sdata=a5tnBOo3%2BvjpMQQsra0V3IO0ewaxcK2dNfGx8%2FZGjRs%3D&reserved=0>
Especially note the figure showing sediment thickness of the Florida Reef. It is based on Hundreds of km of high-resolution seismic profiles and numerous cores. As the map shows the thickness of the Holocene along the tract known as the main reef is less than 2 m thick. (In some places there is no Holocene….just bare Pleistocene with lots of gorgonians and sponges). Because of water depth along this tract it has been underwater at least 6,000 years. So why is it that the main reef line adjacent to Gulfstream waters remains so poorly developed or not developed at all?  As I have pointed out many times the slowest growing coral out there should have outpaced the well-documented rate of rise in sea level over the past 6,000 years.
    Unfortunately anything having to do with coral has become highly politicized. For example, Lauren Toth recently examined and performed around 190 carbon 14 analyses on the reef cores we have been drilling for the past 30 years. From the rates of accretion derived from these dated corals she determined that uniform reef accretion rates have been touch-and-go for the past approximately 3,000 years. Her paper has now been turned down by three different journals. No one wants to believe her fact-based conclusions. The data in fact agrees well with the known thickness of the outer reef line in the Keys.

Phil Dustan also has classic photos showing the demise of the lush A. palmata reef that existed seaward of the Carysfort lighthouse. There is noting but rubble there now (being chewed up by parrot fish).  In conclusion, what became noticeable to divers in the late 1970s has continued until today. The C14 data show growth rates slowed down or ceased about 3,000 years ago when rising sea level created tidal passes that allowed inimical waters from Florida Bay and Hawk channel to periodically flow over the main reef tract.  As Conrad Neumann one published----“the reefs were shot in the back by their own lagoons.” Gene





On 5/7/18 8:27 AM, Pawlik, Joseph wrote:

Hi Gene and list,



Was the peak year for Caribbean coral demise in 1983?



Zlatarski and the Halas did videos of Grecian and Dry Rocks reefs in 1987, capturing the beginning of the end for reefs in the Key Largo Area -- check out these videos (prepare to be depressed).



https://youtu.be/LIbmsHmuxWk<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fyoutu.be%2FLIbmsHmuxWk&data=01%7C01%7Cpawlikj%40uncw.edu%7Ca7e1a11137be4743adb608d5b44bf940%7C2213678197534c75af2868a078871ebf%7C1&sdata=n%2BX1htIoDzpjp4Lxk6Jrc6KegDnjlorpmJ2nWed1j5c%3D&reserved=0>



https://youtu.be/QV-XJZdPbk0<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fyoutu.be%2FQV-XJZdPbk0&data=01%7C01%7Cpawlikj%40uncw.edu%7Ca7e1a11137be4743adb608d5b44bf940%7C2213678197534c75af2868a078871ebf%7C1&sdata=tMNIsieh%2BgLL8s2BPZvooCvW86WqawTIMFTkJNUHfsI%3D&reserved=0>



In 1987, things were still very healthy, but the narration indicates that diseased patches were observed.



Is there any agreement on the span of demise of Acropora in the Caribbean?  For the northern Keys, I would suggest that it's closer to 1988-89, but I'd like confirmation of that by those who were there and monitoring the reefs.



Joe



**************************************************************

Joseph R. Pawlik

Frank Hawkins Kenan Distinguished Professor of Marine Biology

Dept. of Biology and Marine Biology

UNCW Center for Marine Science

5600 Marvin K Moss Lane

Wilmington, NC  28409

Office:(910)962-2377; Cell:(910)232-3579

Website: http://people.uncw.edu/pawlikj/index.html<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fpeople.uncw.edu%2Fpawlikj%2Findex.html&data=01%7C01%7Cpawlikj%40uncw.edu%7Ca7e1a11137be4743adb608d5b44bf940%7C2213678197534c75af2868a078871ebf%7C1&sdata=1UHihSLCjYf6ZOblKa1uqIqthZ2YOszElJ8I5ITf%2BRU%3D&reserved=0>

PDFs: http://people.uncw.edu/pawlikj/pubs2.html<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fpeople.uncw.edu%2Fpawlikj%2Fpubs2.html&data=01%7C01%7Cpawlikj%40uncw.edu%7Ca7e1a11137be4743adb608d5b44bf940%7C2213678197534c75af2868a078871ebf%7C1&sdata=f7gPSFXNw%2F3xyRoW990DFrA6FrEfAsVeaKHVj%2Ff%2BveI%3D&reserved=0>

Video Channel: https://www.youtube.com/user/skndiver011<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.youtube.com%2Fuser%2Fskndiver011&data=01%7C01%7Cpawlikj%40uncw.edu%7Ca7e1a11137be4743adb608d5b44bf940%7C2213678197534c75af2868a078871ebf%7C1&sdata=yTBDNAAHMXSLtV6Y%2F8jsH%2FTBzR%2FYGzUOrQJ5LC1dJdM%3D&reserved=0>

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-----Original Message-----

From: coral-list-bounces at coral.aoml.noaa.gov<mailto:coral-list-bounces at coral.aoml.noaa.gov> <coral-list-bounces at coral.aoml.noaa.gov><mailto:coral-list-bounces at coral.aoml.noaa.gov> On Behalf Of Eugene Shinn

Sent: Thursday, May 3, 2018 12:54 PM

To: coral-list at coral.aoml.noaa.gov<mailto:coral-list at coral.aoml.noaa.gov>

Subject: Re: [Coral-List] Szmant 2002: Great review on nutrient enrichment on coral reefs (Gene Shinn)



John, I agree the Szmant 2002 paper on nutrient enrichment is a classic.

It was one of several papers consulted while we were developing our African dust hypothesis. At the time it was already known that African dust supplied the nutrients that stimulate Amazon rain forest growth.

Thus, African dust also seemed a viable explanation for benthic turf algal blooms and demise of coral reefs around isolated Caribbean islands with small human populations. It was noted early on that the peak year of coral demise throughout the Caribbean was centered around 1983. That was also the peak year of increased dust flux in the Atlantic. During this period of time our USGS research revealed tidal pumping and offshore seepage of nutrient rich ground water. Also at that time many researchers were finding offshore surface waters contained insufficient amounts of nutrients to readily explain benthic turf algal blooms, Thus, seepage of nutrient rich ground water (enriched by anthropogenic sewage

nutrients) combined with sedimentation of atmospheric dust elements might explain turf algal blooms and at the same time explain the relative lack of dissolved nutrients in the overlying water column.



So where are we now? For sure the demise of corals reefs continues throughout the Caribbean and especially in Florida. It seems likely increasing human population in the Keys and continued African dust flux (enhanced by climate change) is ongoing. African dust nutrients are now increasingly recognized as a stimulus for phytoplankton blooms in mid Atlantic surface waters. Many studies have also shown the dust transports viable bacteria and fungi along with toxic elements like mercury and arsenic in addition to pesticides. And now we have sunscreens containing Oxybenzone to contend with. It is increasingly difficult to remain optimistic. Gene



See: Shinn, E.A., Smith, G.W., Prospero, J.M., Betzer, P., Hayes, M.L., Garrison, V., Barber, R.T., 2000, African dust and the demise of Caribbean coral reefs: Geological Research Letters, v. 27, p. 3129-3032.



Also see https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fcoastal.er.usgs.gov%2Fafrican_dust%2Fgallery.html&data=01%7C01%7Cpawlikj%40uncw.edu%7Cb7c8df1161b8417497ae08d5b1c38c02%7C2213678197534c75af2868a078871ebf%7C1&sdata=h4vJogAotNbVB9wmetx64b0FyuGlQllvSLlOAJnYtQs%3D&reserved=0






--





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><mailto:eugeneshinn at mail.usf.edu>

Tel 727 553-1158

---------------------------------- -----------------------------------



--





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><mailto:eugeneshinn at mail.usf.edu>

Tel 727 553-1158

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