Coral Reefs 18 (1): 1997.

by D.L. Santavy*, E.C. Peters, C. Quirolo, J.W. Porter, C.N. Bianchi.
Corresponding author: U.S. Environmental Protection Agency, Gulf Ecology Division, Gulf Breeze, FL., 32561, USA. e-mail: santavy.debbie@epamail.epa.gov

Esther C. Peters
Tetra Tech, Inc.
10306 Eaton Place, Suite 340
Fairfax, VA 22030
(703) 385-6007

Reef Relief’s Craig Quirolo first observed yellowband disease on corals near Key West in 1994 as part of his ongoing multi-year Coral Survey.  He documented the outbreak and alerted Reef Relief Scientific Advisor Dr. James Porter of UGA who arrived with a team that investigated the outbreak and named it yellow band disease.  Some scientists have since determined that it should be called yellow blotch disease.  To see survey images go to:  http://www.reefreliefarchive.org/cgi-local/ImageFolio31/imageFolio.cgi?direct=Yellow_Band_Disease

An extensive outbreak of coral disease was observed affecting the scleractinian corals Montastrea Faveolata and M. Annularis at San Blas, Panama, in the eastern Caribbean region. The first report of this disease referred to it as “yellow-band disease”, and it was observev on colonies of M.faveolata on reefs off Key West, Florida (Reeves 1994). Santavy and Peters (1997) proposed the name “yellow-blotch disease” (YBD based on the unusual pattern of yellowish tissue lightening, and to distinguish it from the yellow band disease reported by Korrubel and Reigl (1998) in the Arabian Gulf. Yellow-blotch disease is characterized by circular to irregularly-shaped patches or wide streaks of lightened transluscent tissue, occuring in no particular pattern on the surface of the colony, but more common on the uppermost surfaces. The color of affected tissue is yellow, not pale brown to white as occurs in bleaching.

Occasionally, bright white transluscent patches of tissue appear adjacent to yellowish ones. The affected tissues otherwise appear grossly normal. The lightened patches frequently, but not always, are adjacent to or form a margin around algal/sediment accumulations on dead coral skeleton. No “band” of clean, denuded skeleton is usually present.

The disease was present on most reefs examined at San Blas in 1996. At the western tip of the Salar Islands group (approximately 78 degrees 48.5’W,9 degrees 31’N), 6 to 18 m deep on the forereef, about 5% of all M. faveolata colonies were affected. Affected colonies had from one small patch of discolored tissue to numerous large patches of algal/sediment accumulations adjacent to yellowish tissues with extensive tissue tissue loss. Yellow-blotch disease was not observed here 25 years ago. The reefs are considered to be relatively spared from anthropogenic pollution and diving pressures. However, our assessment is that a major die-off of M. Faveolata is occurring in San Blas, which is of geological significance since it is the primary reef builder.

Similar signs of disease have been observed on Montastrea spp. Elsewhere, including the severly affected Netherlands Antilles (TJ Goreau and JM Cervino, AW and RJ Bruckner, per. Commm.); Key West; Negril, Jamaica; Isla Cocos and Marie La Gorda, Cuba; and Guanaja and Bay Islands, Honduras. However, the presence of unaffected large and small colonies of M. faveolata suggests that some colonies might be resistant or have not been exposed in a manner that results in an active infection.

Acknowledgement We thank Ken Clifton, the Captain and crew of the Daiquiri, the Smithsonian Tropical research Institute, and the Kuna Indians for their assistence in San Blas. Key West observations were supported by Reef Relief.

https://www.st.nmfs.noaa.gov/StockAssessment/workshop_documents/nsaw5/bohnsack.pdf

by James A. Bohnsack Proceedings, 5th NMFS NSAW. 1999. NOAA Tech. Memo. NMFS-F/SPO-40. NMFS,

http://www.aslo.org/lo/toc/vol_42/issue_5_part_2/1119.pdf

Florida Bay Nutrients: Perspectives on the July 1-2, 1996 workshop

Report of the  Florida Bay Science Oversight Panel Ad Hoc Committee on Nutrients, National Academy of Science 

D.F. Boesch (Chair), J.M. Caffrey, J.E. Cloern, C.F. D’Elia, D. M. DiToro and W. W. Walker,Jr.
Submitted to the  Program Management Committee, Florida Bay Research Program 15 July 1996

This was the first official recognition that the Everglades plan to increase the flow of polluted water from the mainland into Florida Bay was flawed and could have serious impacts on Florida Bay and the downstream coral reefs of the Florida Keys.

SUMMARY
An Ad Hoc Committee on Nutrients convened under the auspices of the Florida Bay Science Oversight Panel participated in a two-day workshop of investigators and program managers on nutrients in Florida Bay. It was asked to evaluate the adequacy of databases and research and monitoring programs for deriving inferences about nutrient sources and processes in Florida Bay and how they may change as freshwater inflows increase in association with hydrological restoration of South Florida. The Committee’s main perspectives and recommendations are summarized below:

An important determinant of the supply of nutrients to the Bay is water flow and circulation, the most poorly quantified element of which is the exchange between western and central Florida Bay. There should be a concerted effort using salinity modeling, tracers and flow measurements to quantify these exchanges and their importance in supplying phosphorus (from deeper Gulf waters) and nitrogen (from the Shark Slough plume into western and central Florida Bay).

Although nutrient concentrations in freshwater effluents from the Everglades are now adequately monitored, because of the limited duration and high variability of the record recent variations in nutrient concentrations cannot be confidently attributed to water-management practices. The transport and transformation of nitrogen across the mangrove/estuarine transition and in the coastal flows toward Florida Bay remain important unknowns.

Box models of nutrient budgets for Florida Bay should be developed which include the major forms of N and P and at least three different geographic segments – western (west of Everglades National Park boundary), central and eastern – as a parallel and contributory exercise with the planned numerical simulation model.

In the shallow, warm, well lit Florida Bay cycling and transformation of nutrients may be as important as sources and concentrations in affecting plant growth. The current research on phytoplankton and biogeochemical processes should be expanded to focus on mechanisms of nutrient cycling rather than simply making inferences from nutrient distribution patterns.

Studies of nutrient limitation have shown that nitrogen limits phytoplankton growth in the western Bay, several nutrients may co-limit growth in the central Bay, and phosphorus typically limits growth in the eastern Bay. Understanding the causes of algal blooms now requires process studies using modern tracer and enzymatic techniques, intense time-series rather than semi-annual or monthly measurements, and field or mesocosm, as well as in vitro, experiments. The Program Management Committee (PMC) should explore opportunities for engaging experts in such approaches and facilitating the intense multidisciplinary studies required. The data and observations in support of the divergent perspectives offered regarding the effect on the coral reefs of export of nutrients from Florida Bay of the Florida Keys Marine Sanctuary are sketchy and anecdotal. Nutrient transport mechanisms and concentrations and grazing pressure on macroalgae must be considered together in addressing this question. The Florida Bay Research Program could contribute to the first of these factors.

Concerns about the comparability of chlorophyll and nutrient data were raised. Data comparability is essential and quality assurance/quality control exercises now being undertaken should be expanded and maintained.

Inconsistency of geographic references contributes confusion and interferes with the development of scientific consensus. The PMC should oversee an effort to develop a common set of names and boundaries for regions of Florida Bay. To the extent practicable, a common set of reference sites should also be selected for field measurements and experiments.

A nutrient-plankton bloom team of investigators should be formed to facilitate interpretation and use of monitoring and research data.

The Committee fully supports the PMC’s efforts to develop a coupled circulation-ecosystem model of Florida Bay as a tool to systemize data, pose hypotheses, and anticipate the effects of different water management scenarios. The coupled model should be designated to describe the dynamics of these key features of the Florida Bay ecosystem: (1) coupled hydrodynamic-nutrient-phytoplankton-water quality variability, (2) suspended sediments and their influence on turbidity, and (3) seagrass populations and their influence on sediment resuspension, nutrient cycling and geochemistry.
Although hydrologic flow and water level goals guide the restoration of the Everglades, no specific restoration goals for Florida Bay have been set which could guide research as well as management activities. A subcommittee or task force of specifically address the restoration goals for Florida Bay.

Because the freshwater effluent of the Everglades has very low concentrations of phosphorus and phytoplankton and macroalgal growth in the northeastern Florida Bay is strongly phosphorus limited, the Committee’s provisional judgement is that the planned redistribution of fresh water into the Taylor Slough system will not lead to or worsen acute symptoms of over-enrichment in Florida Bay. However, the consequences of this plan have not been assessed with even simple mass balance models and must be regarded as uncertain as this point.

For more info, go to:  http://www.nap.edu/openbook.php?record_id=10479&page=9  Florida Bay Research Programs and their relation to the Everglades Restoration Plan (2002).

Roland E. Ferry, Ph.D.-Water Management Division/Coastal Programs Section

Note:  Reef Relief’s Craig Quirolo provided vessel and technical support for this study, which helped us finally end ocean dumping in Key West. This outfall has been replaced with advanced nutrient-stripped wastewater treatment and a deep injection well.

Summary:
The US Environmental Protection Agency, Region4, directed and conducted a series of studies of the Key West Florida wastewater treatment plant ocean outfall from August 1993 to November 1994: The studies examined local hydrographic conditions, effluent transport and dilution in the receiving waters, geochemical and biological fate of effluent constituents, wastewater contributions to the benthos and to local eutrophication and impacts to macrobenthic communities.

Hydrodynamic conditions in the immediate area around the outfall on the ebb tides tend to transport effluent to the east, roughly parallel to the southern shorelines of the lower Keys and to the north into the Gulf of Mexico on the flood tide. High velocity tidal currents appear to confine the effluent largely to areas east of the Key West navigation channel. Effluent dilution exceeds 90:1 within 750 meters of the outfall and approaches 1000:1 within 2500 meters. Modeling results predict dilutions exceeding 32,000:1 at offshore bank reefs.

Nitrogen and carbon stable isotope studies indicate that outfall particulates are not a major component of particulate matter in benthic environments near the outfall or offshore bank reefs and that seagrass inputs are a primary source of sediment nitrogen in the area. The isoptopic dissimilarity between effluent and sediments suggest weak pelagic-benthic coupling in the area, probably due to strong currents and high rates of dilution. Outfall particulates do, however, appear to comprise a major component of the diet of some filter feeding macrobenthic organisms near the outfall, but not a major contributor of nitrogen to marine macrophyes around the outfall.

Coprostanol (fecal sterol) analysis of area sediments indicated sewage contamination of the benthos for several kilometers north and south of the outfall and along the southern shore of Key West. The outfalls relative contribution to sediment contamination cannot be distinguished from that of other likely (live-aboards mooring fields) and potential (ship discharges) sources of domestic wastes.

Benthic infaunal community analysis determined that there is no significant structural differences in macroinfaunal between communities in a sewage contaminated area by wastes and communities in an uncontaminated reference location.

The results of this series of studies indicate that wastewater effluent impacts from the Key West ocean outfall are mainly limited to localized eutrophication and contributions to some sewage contamination of the benthos in the vicinity of the outfall. The probability of transport of any significant amounts of outfall contaminants to offshore bank reefs appears to be low.