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3. Integrating Hydrodynamic Modeling with Ecological Risk Assessment for Selecting Sites for Artificial Reef Deployment: Avoiding Coastal Pollution Risks in Kish Island, Persian Gulf.

Author

Doust, Shadan Nasseri, Abbasian, Mehrnoosh, Haghshenas, S. Abbas, Risk, Michael J., and Downs, Craig A.

Subjects
ECOLOGICAL risk assessment, ARTIFICIAL reefs, CORAL declines, GEOGRAPHIC information systems, WATER quality, CORAL reefs & islands
Abstract

The decline of natural coral reefs has spurred interest in artificial reef construction and reef rehabilitation efforts. However, many restoration programs are failing because of poor water quality and localized pollution factors. This paper examines one etiology of coral restoration failure, highlighting the need for careful site selection based on hydrodynamic, biological, and pollution criteria. Using Kish Island as a case study, we outline a procedure for determining placement of artificial reefs to minimize external pollution impacts, which could be applied to any reef site worldwide. Our integration of computational modeling and geographic information systems enables the tracking of pollution dispersion and increases the power of restoration efforts. The RQ Plume modeling, used alongside compound pollutant modeling, can identify hotspots with the highest potential to degrade marine environments, particularly reefs. Conservation efforts should prioritize pollution mitigation, as seen in the case of sunscreen pollutants at Kish Island, where regulatory action and public education can contribute to reef protection. This comprehensive approach underscores the critical role of water quality in successful reef restoration and conservation strategies. [ABSTRACT FROM AUTHOR]

Published
2024
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31. Oxybenzone contamination from sunscreen pollution and its ecological threat to Hanauma Bay, Oahu, Hawaii, U.S.A

Author

0000-0002-8486-9816, 0000-0001-7532-2934, 0000-0001-5134-1196, 0000-0002-2514-4516, 0000-0001-8823-9814, Downs, C. A., Bishop, Elizabeth, Díaz-Cruz, M. Silvia, Haghshenas, S. Abbas, Stien, Didier, Rodrigues, Alice M. S., Woodley, Cheryl M., Sunyer-Caldú, Adrià, Doust, Shadan Nasseri, Espero, William, Ward, Gene, Farhangmehr, Aref, Tabatabaee Samimi, S. Maryam, Risk, Michael J., Lebaron, Philippe, DiNardo, Joseph C., 0000-0002-8486-9816, 0000-0001-7532-2934, 0000-0001-5134-1196, 0000-0002-2514-4516, 0000-0001-8823-9814, Downs, C. A., Bishop, Elizabeth, Díaz-Cruz, M. Silvia, Haghshenas, S. Abbas, Stien, Didier, Rodrigues, Alice M. S., Woodley, Cheryl M., Sunyer-Caldú, Adrià, Doust, Shadan Nasseri, Espero, William, Ward, Gene, Farhangmehr, Aref, Tabatabaee Samimi, S. Maryam, Risk, Michael J., Lebaron, Philippe, and DiNardo, Joseph C.

Abstract

Hanauma Bay is a 101-acre bay created by the partial collapse of a volcanic cone and once supported a vibrant coral reef system. It is the most popular swimming area in the Hawaiian Islands and has been reported to have averaged between 2.8 and 3.5 million visitors a year between the 1980s and the 2010s, with visitors averaging between 3000-4000 a day and peaking around 10,000-13,000 per day. Concentrations of oxybenzone and other common UV filters were measured in subsurface water samples and in sands from the beach-shower areas in Hanauma Bay. Results demonstrate that beach showers also can be a source of sunscreen environmental contamination. Hydrodynamic modeling indicates that oxybenzone contamination within Hanauma Bay's waters could be retained between 14 and 50 h from a single release event period. Focusing on only oxybenzone, two different Hazard and Risk Assessment analyses were conducted to determine the danger of oxybenzone to Hanauma Bay's coral reef system. Results indicate that oxybenzone contamination poses a significant threat to the wildlife of Hanauma Bay. To recover Hanauma Bay's natural resources to a healthy condition and to satisfactorily conserve its coral reef and sea grass habitats, effective tourism management policies need to be implemented that mitigate the threat of sunscreen pollution.

Published
2021

41. Relationship between light and the delta15-N of coral tissue: examples from Jamaica and Zanzibar

Author

Heikoop, Jeffrey M., Dunn, Jennifer J., Risk, Michael J., Sandeman, Ian M., Schwarcz, Henry, and Waltho, Nigel

Subjects
Corals -- Research, Nitrogen -- Isotopes, Earth sciences
Abstract

Corals with symbiotic zooxanthellae have a nitrogen isotopic composition that is affected by light, according to analysis of samples from Jamaica and Zanzibar. Under conditions of high irradiance, the coral internal pool of dissolved inorganic nitrogen (DIN) appears to become depleted through uptake and assimilation by the symbiotic algae and/or the host, and fractionation is reduced. In conditions of lower light, fractionation increases as less dissolved nitrogen is assimilated. Delta15-N is lower in coral tissues when the light is lower.

Published
1998

42. Modern iron ooids from a shallow-marine volcanic setting: Mahengetang, Indonesia

Author

Heikoop, Jeffrey M., Tsujita, Cameron J., Risk, Michael J., Tomascik, Tomas, and Mah, Anmarie J.

Subjects
Indonesia -- Natural history, Iron ores -- Natural history, Submarine geology -- Research, Geochemistry -- Research, Earth sciences
Abstract

An unconsolidated submarine deposit of iron ooids and pisoids, located offshore the volcanic island Mahengetang, Indonesia, is described herein. The deposit occurs in a shallow-marine setting, in an area characterized by venting of hydrothermal fluids and expulsion of gas across the sediment-water interface. The ooid deposit is essentially pure to a minimum depth of 0.5 m and covers an area of at least 1000 [m.sup.2]. Ooids are composed of concentric accretionary layers of limonite admixed with amorphous silica, precipitated around andesitic rock fragments. The smallest layers forming the ooids are about 10 [Mu] in thickness. The iron-rich precipitate is [approximately]50% iron by weight. Ooid formation is likely promoted by precipitation of iron and silica from exhalative fluids rising up through the substrate. Concentric layering is thought to result from constant agitation of ooids associated with currents and expulsion of gas from the sediment.

Published
1996

46. El Arrecife Coralino del Parque Nacional Cahuita, Costa Rica

Author

Cortés, Jorge and Risk, Michael J.

Abstract

The coral reef at Parque Nacional Cahuita, Limón, Costa Rica, is a reef under stress due to siltation. The amount of suspended sediments is high and resuspension of bottom sediments is also high. Growth rates of corals, live coral coverage and diversity were low. Colonies are generally larger than in other areas studied, and recruitment of planulae seems to be low. Most of the corals present are good at rejecting sediments and morphologies of some change to better resist the sediments (vertical fronds of Agaricia agaricites) or to receive more light (shingles of Montastrea annularis and Porites astreoides).Analyses of the currents and the type of minerals present in the noncarbonate fraction of the sediments at the reef point to Río La Estrella as the source of sediments. The amount of sediments carried by this river has probably increased recently as a result of watershed deforestation. The problem of siltation in reef environments is bound to increase as new areas in the tropics are being developed.Sediments affect both the individual coral and the coral community. Whether a reef is (or was) under stress due to siltation, can be determined by analyzing the following: growth rates of the corals, amount of trapped sediments in the skeletons, live coral coverage, species composition and diversity, and morphologies. El arrecife coralino del Parque Nacional Cahuita, Limón, se caracteriza por: 1- alta concentración de sedimentos en suspensión; 2- altas tasas de re suspensión de sedimentos; 3- porcentaje carbonático relativamente bajo de los sedimentos del fondo; 4- baja tasa de crecimiento coralino; 5- bajo porcentaje de cobertura de coral vivo ; 6- baja diversidad de corales; 7- colonias de mayor tamaño que en otras áreas estudiadas y, parece que el reclutamiento de larvas plánulas es bajo. Los corales que más abundan son los más resistentes a los sedimentos. La morfología de algunas especies cambia en respuesta a la reducción de luz, causada por los sedimentos y en res· puesta a los sedimentos per se. La profundidad óptima de algunas especies es menor que en otras áreas del Caribe.Las observaciones y los resultados apuntan al Río La Estrella como la fuente de sedimentos que está afectando al arrecife de Cahuita, y es posible que la cantidad de estos sedimentos haya aumentado recientemente debido a la deforestación de su cuenca.Los sedimentos afectan tanto a los corales individuales como a toda la comunidad coralina. Es factible determinar si los sedimentos son (o fueron) un problema en un arrecife mediante el análisis de los siguientes parámetros: tasa de crecimiento de los corales, cantidad de sedimentos atrapada en su esqueleto, cobertura de coral vivo, composición y diversidad de especies y finalmente, su morfología y tamaño.

Published
2017
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