Human Excrement to Blame for Coral Decline

From Science News Weekly headlines:

by Gisela Telis on 17 August 2011, 5:00 PM

Coral killer. Bacteria found in human excrement cause white pox disease, which bares coral skeletons and kills their tissue.

Credit: James W. Porter/University of Georgia

Coral reef ecologists have laid a persistent and troubling puzzle to rest. The elkhorn coral, named for its resemblance to elk antlers and known for providing valuable marine habitat, was once the Caribbean's most abundant reef builder. But the "redwood of the coral forest" has declined 90% over the past decade, in part due to highly contagious white pox disease, which causes large lesions that bare the coral's white skeleton and kill its tissue. Now, after nearly a decade of data collection and analysis, researchers have fingered the cause of the affliction: human excrement. The finding represents the first example of human-to-invertebrate disease transmission and suggests a practical approach for halting the disease's spread.

"This is a really important bit of work," says coral researcher Thomas Goreau of the Global Coral Reef Alliance in Cambridge, Massachusetts. "I would say they've now proven their case beyond any doubt."

Nine years ago, a research team led by coral reef ecologists Kathryn Sutherland, now of Rollins College in Winter Park, Florida, and James Porter of the University of Georgia, Athens, linked white pox to a bacterium called Serratia marcescens, which is found in the intestines of humans and a handful of other animals. In humans, Serratia can cause respiratory and urinary tract infections. But although Sutherland and her team strongly suspected human waste—stemming from septic tanks that leak sewage into the Florida Keys's porous bedrock—was the culprit, they had no proof that the disease didn't start with Key deer, cats, seagulls, or any of the Caribbean's other Serratia-harboring wildlife. "There was considerable skepticism—it was too easy to blame other things," Porter says.

The duo and colleagues spent years collecting Serratia samples from healthy and diseased corals, from humans via a wastewater treatment facility in Key West, and from other animals. To obtain each sample's genetic fingerprint, they added an enzyme that breaks up the bacterium's genome wherever a specific gene sequence is found.

Because every strain's genome differs slightly, each one yields a unique pattern of breaks. Comparing the patterns among all their samples, the team found only two that matched each other exactly: the Serratia strain found in white pox-afflicted coral and the one drawn from human waste.

To dispel any remaining doubt, the researchers cultivated small fragments of healthy, Serratia-free coral in the lab, and then exposed these to the human-specific strain. Within as little as 4 days, the healthy coral showed signs of white pox infection, they report today in PLoS ONE.

In the Florida Keys and the Caribbean, where sea-based tourism and recreation pump billions into the economy each year, the discovery has significant implications, Porter says.

Sutherland and Porter hope their new evidence will encourage communities throughout the Caribbean to upgrade their waste management facilities, replacing septic tanks ill-suited for the region's geography and geology with wastewater treatment plants. Key West has not seen a single new case of white pox since its transition to an advanced wastewater treatment facility in 2001, the researchers say.



Robert Glazer

Associate Research Scientist

Florida Fish and Wildlife Conservation Commission

Fish and Wildlife Research Institute

2796 Overseas Highway, Ste. 119

Marathon, FL 33050

305-289-2330; 305-289-2334 (fax)

[email protected]

research.myfwc.com

Replies

  • Permit RatPermit Rat Posts: 2,283 Captain
    I read that, earlier. But I am curious.....Has anyone noticed the beginnings of a "coral comeback" in the Keys? (specifically Key West area) I don't remember staghorn coral, as it was pretty much gone by the late 70's. But there were some pretty good stands of elkhorn in places. Then that was gone too.

    While this study is great and I am very glad that Key West has done something about it, it is too bad that this is but just one reason for the demise of coral reefs worldwide. I'm afraid there's not much we can do in terms of the rising water temps. and that is taking its toll as well.
    .......Rick
  • keylargo359keylargo359 Posts: 1,249 Officer
    I am No scientist but I have been saying it for a long time any depletion of reef fish stock is not due to over fishing.But due to habitat loss and that is due to pollution and run off.The best thing they have done in the Keys is put every one on sewer systems rather than septic tanks but it is way to early to tell what kind of affect it will have I don't believe that they have completed the project of getting people in the keys hooked to the new sewer system.
    The worst day of fishing is still better than the best day of work:\
  • mikeloewmikeloew Posts: 327 Deckhand
    I am No scientist but I have been saying it for a long time any depletion of reef fish stock is not due to over fishing.But due to habitat loss and that is due to pollution and run off.The best thing they have done in the Keys is put every one on sewer systems rather than septic tanks but it is way to early to tell what kind of affect it will have I don't believe that they have completed the project of getting people in the keys hooked to the new sewer system.

    I agree, I also wonder if putting tighter restrictions on all the liveaboards that are not in a Marina with pump out services would help. I have to believe there are a large percentage of these folks that empty their tanks when no one is looking. I also wonder if moving the legal holding tank dumping limits farther out, would help. I think right now they are three statute miles on the Atlantic side of the Florida Keys and nine nautical miles on the Gulf side. I am usually not in favor of more restrictions on us boaters, and I am not trying to discourage the folks that are passing through, and anchoring up for a few days, I am talking about the long term people with barely floating boats that seem to be there for years that live aboard their boats. I have never seen a pump out boat service, visit their boats?
    Marathon vacation home for rent

    http://www.floridakeyshomeforrent.com/
  • keylargo359keylargo359 Posts: 1,249 Officer
    I am sure if you look at the whole picture you could do a lot to help with the quality of the water on our reef systems starting with instead of keeping all the Florida residence from fishing. and continuing to close areas due to bad science and pressure from commercial dive operators.Maybe they should limit the amount of dive operators and the amount of people they can take out to any reef on any given day. I have seen as many as three or four dive operations on one reef at one time with any where from 15 to 30 people in the water from each boat Pi$$ing and ***^%^& all over the reef and these boats make at least two or more trips a day and if that doesn't do more damage than a few people a week fishing any given spot I'll Kiss your &^% and give you thirty minutes to draw a crowed. not to mention the park service itself is motivated by $$$ more than any reason. to protect the reef they have what I call a cattle boat (sight seeing boat) that is almost as wide as the Chanel it takes to get to the reef.so big that as it goes out the Chanel you see the huge mud trail it kicks up and from what I understand suet is the worst thing you can put on coral yet this boat makes two trips a day every day how do you Justify that.:blahblah I could go on but I'll save it for later:blahblah
    The worst day of fishing is still better than the best day of work:\
  • lwrenlwren Posts: 142 Officer
    The words shallow well injection for treated sewage make me cringe. Even the deep injection wells should be studied. Pipe the sewage to a plant that can treat it and not pump it back into the reef system. I would also delacre the keys to bult out and no more new development until this sewage problem is conquered.
    Thanks Larry
    First Choice Islamorada Fishing Charters
    305-360-4900
    [SIGPIC][/SIGPIC]
  • lwrenlwren Posts: 142 Officer
    As of June 16th all vessels in the marine sanctuary are not allowed any overboard discharge. Theses water don't end at the three mile limit. The new laws also prohibit treated black water discharges also.
    Thanks Larry
    First Choice Islamorada Fishing Charters
    305-360-4900
    [SIGPIC][/SIGPIC]
  • mikeloewmikeloew Posts: 327 Deckhand
    lwren wrote: »
    As of June 16th all vessels in the marine sanctuary are not allowed any overboard discharge. Theses water don't end at the three mile limit. The new laws also prohibit treated black water discharges also.

    Thanks for the info Larry. Do you know where do they end?
    Marathon vacation home for rent

    http://www.floridakeyshomeforrent.com/
  • razorreilly09razorreilly09 Posts: 8,401 Officer
    lwren wrote: »
    The words shallow well injection for treated sewage make me cringe. Even the deep injection wells should be studied. Pipe the sewage to a plant that can treat it and not pump it back into the reef system. I would also delacre the keys to bult out and no more new development until this sewage problem is conquered.
    I have worked at several of the wastewater plants in the Keys. Its a mix of treating and pumping down injection wells and the plants that redistribute reuse/reclaimed water for irrigation and boat cleaning. There is not enough demand for a lot of reuse throughout the Keys. There is some mostly for resort and golf course use, the rest gets pumped into the ground. It is treated, then hypo chlorinated to kill anything living in it. Im no scientist or environmental specialist but cant see how chlorinated water being pumped into ocean water can be good. Its a lose-lose situation, we need to support the proper treatment of our wastewater but like most things, the better the quality, the costlier it is. If we go into a serious drought, the reclaimed water is sometimes trucked out of the Keys for golf courses and other irrigation needs in other areas under restrictions.
  • lwrenlwren Posts: 142 Officer
    I thought they sanctuary waters go to the 300 foot area in my area, like the three mile line it varies.
    http://floridakeys.noaa.gov/zones/welcome.html?s=zones

    SANCTUARY DESIGNATION

    SEC. 5.(a) DESIGNATION.—The area described in subsection (b) is designated as the Florida Keys National Marine Sanctuary (in this Act referred to as the “Sanctuary”) under title III of the Marine Protection, Research, and Sanctuaries Act of 1972 (16 U.S.C. 1431 et seq.). The Sanctuary shall be managed and regulations enforced under all applicable provisions of such title III as if the Sanctuary had been designated under such title.

    (b) AREA INCLUDED.—(1) Subject to subsections (c) and (d), the area referred to in subsection (a) consists of all submerged lands and waters, including living marine and other resources within and on those lands and waters, from the mean high water mark to the boundary described under paragraph (2), with the exception of areas within the Fort Jefferson National Monument. The Sanctuary shall be generally identified and depicted on National Oceanic and Atmospheric Administration charts FKNMS 1 and 2, which shall be maintained on file and kept available for public examination during regular business hours at the Office of Ocean and Coastal Resource Management of the National Oceanic and Atmospheric Administration and which shall be updated to reflect boundary modifications under this section.

    (2) The boundary referred to in paragraph (1)—

    (A) begins at the northeasternmost point of Biscayne National Park located at approximately 25 degrees 39 minutes north latitude, 80 degrees 5 minutes west longitude, then runs eastward to the 300-foot isobath located at approximately 25 degrees 39 minutes north latitude, 80 degrees 4 minutes west longitude;

    (B) then runs southward and connects in succession the points at the following coordinates:

    (i) 25 degrees 34 minutes north latitude, 80 degrees 4 minutes west longitude,

    (ii) 25 degrees 28 minutes north latitude, 80 degrees 5 minutes west longitude, and

    (iii) 25 degrees 21 minutes north latitude, 80 degrees 7 minutes west longitude;

    (C) then runs southward to the northeastern corner of the existing Key Largo National Marine Sanctuary located at 25 degrees 16 minutes north latitude, 80 degrees 8 minutes west longitude;

    (D) then runs southwesterly approximating the 300-foot isobath and connects in succession the points at the following coordinates:

    (i) 25 degrees 7 minutes north latitude, 80 degrees 13 minutes west longitude,

    (ii) 24 degrees 57 minutes north latitude, 80 degrees 21 minutes west longitude,

    (iii) 24 degrees 39 minutes north latitude, 80 degrees 52 minutes west longitude,

    (iv) 24 degrees 30 minutes north latitude, 81 degrees 23 minutes west longitude,

    (v) 24 degrees 25 minutes north latitude, 81 degrees 50 minutes west longitude,

    (vi) 24 degrees 22 minutes north latitude, 82 degrees 48 minutes west longitude,

    (vii) 24 degrees 37 minutes north latitude, 83 degrees 6 minutes west longitude,

    (viii) 24 degrees 40 minutes north latitude, 83 degrees 6 minutes west longitude,

    (ix) 24 degrees 46 minutes north latitude, 82 degrees 54 minutes west longitude,

    (x) 24 degrees 44 minutes north latitude, 81 degrees 55 minutes west longitude,

    (xi) 24 degrees 51 minutes north latitude, 81 degrees 26 minutes west longitude, and

    (xii) 24 degrees 55 minutes north latitude, 80 degrees 56 minutes west longitude;

    (E) then follows the boundary of Everglades National Park in a southerly then northeasterly direction through Florida Bay, Buttonwood Sound, Tarpon Basin, and Blackwater Sound;

    (F) after Division Point, then departs from the boundary of Everglades National Park and follows the western shoreline of Manatee Bay, Barnes Sound, and Card Sound;

    (G) then follows the southern boundary of Biscayne National Park and the northern boundary of Key Largo National Marine Sanctuary to the southeasternmost point of Biscayne National Park; and

    (H) then follows the eastern boundary of the Biscayne National Park to the beginning point specified in subparagraph (A).

    (c) AREAS WITHIN STATE OF FLORIDA.—The designation under subsection (a) shall not take effect for any area located within the waters of the State of Florida if, not later than 45 days after the date of enactment of this Act, the Governor of the State of Florida objects in writing to the Secretary of Commerce.

    (d) BOUNDARY MODIFICATIONS.—No later than the issuance of the draft environmental impact statement for the Sanctuary under section 304(a) (1) (C) (vii) of the Marine Protection, Research, and Sanctuaries Act of 1972 (16 U.S.C. 1434(a) (1) (C) (vii)), in consultation with the Governor of the State of Florida, if appropriate, the Secretary of Commerce may make minor modifications to the boundaries of the Sanctuary as necessary to properly protect sanctuary resources. The Secretary of Commerce shall submit to the Committee on Commerce, Science, and Transportation of the Senate and the Committee on Merchant Marine and Fisheries of the House of Representatives a written notification of such modifications. Any boundary modification made under this subsection shall be reflected on the charts referred to in subsection (b) (l).

    PROHIBITION OF CERTAIN
    Thanks Larry
    First Choice Islamorada Fishing Charters
    305-360-4900
    [SIGPIC][/SIGPIC]
  • keewestgrlkeewestgrl Posts: 192 Deckhand
    I have worked at several of the wastewater plants in the Keys. Its a mix of treating and pumping down injection wells and the plants that redistribute reuse/reclaimed water for irrigation and boat cleaning. There is not enough demand for a lot of reuse throughout the Keys. There is some mostly for resort and golf course use, the rest gets pumped into the ground. It is treated, then hypo chlorinated to kill anything living in it. Im no scientist or environmental specialist but cant see how chlorinated water being pumped into ocean water can be good. Its a lose-lose situation, we need to support the proper treatment of our wastewater but like most things, the better the quality, the costlier it is. If we go into a serious drought, the reclaimed water is sometimes trucked out of the Keys for golf courses and other irrigation needs in other areas under restrict

    Actually, the Key West wastewater treatment plant upgraded to advanced wastewater treatment including UV disinfection (eliminating chlorination) and a final effluent polishing before injecting the treated wastewater into a steel and concrete lined deep injection well half a mile deep. There is actually a second well in the event of a failure with the first well. Up until 1989, Key West was discharging raw, untreated sewage through an ocean outfall (pipe) directly off the coast. This outfall pipe has had a large section cut out of it so that it can never be used again. Cesspits and septic tanks are the main culprits of nearshore contamination today. In short, coral rock does not hold water. Until the entire chain of islands adopts a better wastewater treatment plan, bacteria and other pollutants will continue to make their way into the nearshore waters.
  • AmericanAmerican Posts: 130 Officer
    This is really interesting stuff and seems to coincide with the newly fast tracked proposals to close large areas to fishing.

    Unfortunately, I believe the damage has already been done. I am no tree hugger, but our planet is overwhelmed by the excrement that results from overpopulation.
Sign In or Register to comment.