The Toxicity of Oil and Chemically Dispersed Oil to the Seagrass

Author(s):  
BJ Baca ◽  
CD Getter
Author(s):  
M. Scholten ◽  
J. Kuiper ◽  
H. Het Van Groenewoud ◽  
G. Hoornsman ◽  
E. Van Der Vlies

2020 ◽  
Vol 7 ◽  
Author(s):  
Merv F. Fingas ◽  
Kaan Yetilmezsoy ◽  
Majid Bahramian

An algorithm utilizing four basic processes was described for chemical oil spill dispersion. Initial dispersion was calculated using a modified Delvigne equation adjusted to chemical dispersion, then the dispersion was distributed over the mixing depth, as predicted by the wave height. Then the droplets rise to the surface according to Stokes’ law. Oil on the surface, from the rising oil and that undispersed, is re-dispersed. The droplets in the water column are subject to coalescence as governed by the Smoluchowski equation. A loss is invoked to account for the production of small droplets that rise slowly and are not re-integrated with the main surface slick. The droplets become less dispersible as time proceeds because of increased viscosity through weathering, and by increased droplet size by coalescence. These droplets rise faster as time progresses because of the increased size. Closed form solutions were provided to allow practical limits of dispersibility given inputs of oil viscosity and wind speed. Discrete solutions were given to calculate the amount of oil in the water column at specified points of time. Regression equations were provided to estimate oil in the water column at a given time with the wind speed and oil viscosity. The models indicated that the most important factor related to the amount of dispersion, was the mixing depth of the sea as predicted from wind speed. The second most important factor was the viscosity of the starting oil. The algorithm predicted the maximum viscosity that would be dispersed given wind conditions. Simplified prediction equations were created using regression.


1985 ◽  
Vol 1985 (1) ◽  
pp. 547-551 ◽  
Author(s):  
Anthony H. Knap ◽  
Sheila C. Wyers ◽  
Richard E. Dodge ◽  
Thomas D. Sleeter ◽  
Harold R. Frith ◽  
...  

ABSTRACT The Coroil project in Bermuda has been an intensive, multidisciplinary study of the effects of physically and chemically dispersed Arabian light crude oil on the main reef-building coral in Bermuda, Diploria strigosa. This paper reviews the results of this three year study. Corals were exposed to dispersed oil in a flow system, using spectrofluorimetry and gas chromatography to characterize and quantify the dose. Appropriate controls were included in all experiments. The studies included effects of dispersed oil on survival and behavior, the uptake and depuration of petroleum hydrocarbons, photosynthesis by symbiotic zoo-xanthellae, and skeletal growth. In behavioral and growth studies, corals were dosed in the laboratory or in the field. Laboratory-dosed colonies were returned to the field to determine long-term effects. Exposure to 20 ppm of chemically dispersed oil for 24 hours induced various behavioral reactions, including tentacle retraction, tissue contraction and mesenterial filament extrusion. However, effects were typically sublethal, and recovery was usually evident within four days. These symptoms were not significant in long-term transplants. Using the alizarin red staining technique, no long-term effects on skeletal growth could be detected following any of our treatments. Depuration studies using (9-I4C) -phenanthrene and gas chromatographic analysis showed that the uptake of petroleum hydrocarbons by the tissue of Diploria was rapid, but 75 percent of the hydrocarbon dose was eliminated within 14 days. Photosynthesis studies showed a short-term inhibition of photosynthesis only by chemically dispersed oil, with lipid synthesis being most severely affected. Total recovery occurred within 24 hours of exposure.


1989 ◽  
Vol 1989 (1) ◽  
pp. 447-454 ◽  
Author(s):  
Thomas G. Ballou ◽  
Stephen C. Hess ◽  
Richard E. Dodge ◽  
Anthony H. Knap ◽  
Thomas D. Sleeter

ABSTRACT A multidisciplinary long-term field experiment was conducted to evaluate the use of chemical dispersants to reduce the adverse environmental effects of oil spills in nearshore, tropical waters. Three study sites, whose intertidal and subtidal components consisted of mangroves, seagrass beds, and coral reefs, were studied in detail before, during, and after exposure to untreated crude oil or chemically dispersed oil. This study simulated an unusually high (“worst case”) exposure level of dispersed oil and a moderate exposure level of untreated oil. The third site served as an untreated reference site. Assessments were made of the distribution and extent of contamination by hydrocarbons over time, and the short- and long-term effects on survival, abundance, and growth of the dominant flora and fauna of each habitat. The whole, untreated oil had severe, long-term effects on survival of mangroves and associated fauna, and relatively minor effects on seagrasses, corals, and associated organisms. Chemically dispersed oil caused declines in the abundance of corals, sea urchins, and other reef organisms, reduced coral growth rate in one species, and had minor or no effects on seagrasses and mangroves. Conclusions were drawn from these results on decision making for actual spills based on trade-offs between dispersing or not dispersing the oil. This report deals only with the major results of the study. A large number of parameters were monitored, but in the interest of brevity only the most important aspects of the study are reported here. A detailed description of the methods used and a complete presentation and discussion of results is given in Ballou et al.2


2014 ◽  
Vol 2014 (1) ◽  
pp. 733-746 ◽  
Author(s):  
Adriana C. Bejarano ◽  
Valerie Chu ◽  
Jeff Dahlin ◽  
Jim Farr

ABSTRACT The Deepwater Horizon oil spill revived discussions on the use of dispersants as an oil spill countermeasure. One of the greatest concerns regarding the use of dispersants deals with potential exposure of water column organisms to high concentrations of oil. While toxicity data on dispersants and physically and chemically dispersed oil have been generated for decades under controlled laboratory conditions, the practical use of this information has been limited by the lack of a centralized data repository. As a result, the Dispersant and Chemically Dispersed Oil Toxicity Database (DTox) was created to address that shared need of unrestricted and rapid access to toxicity data. DTox is a quantitative database that gathers existing toxicity data through a careful review and compilation of data extracted from the peer-review and gray literature. Through a rigorously evaluation of the quality of each data source, this database contains pertinent information including species scientific name, life stage tested, dispersant name, exposure type, oil weathering stage, exposure duration, etc. More importantly, this database contains effects concentrations reported on measured or nominal basis. Within the database, each data source is assigned an applicability score based on their relevance to oil spills. Key criteria in the determination of source applicability include exposure type, reported effects concentrations, and reported analytical chemistry. Information in DTox has been further integrated into a user-friendly tool that allows for on-the-fly data searches and data plotting in the form of Species Sensitivity Distributions. To date, +400 papers have been evaluated for potential inclusion into the database, and data extracted from +170 sources. Despite inherent limitations, existing toxicity data are of great value to the oil spill scientific community. Although toxicity data will never be enough to answer all toxicity questions regarding the use of dispersants, this centralized data repository can help inform decisions on dispersant use and can help identify data needs and gaps. The ultimate goal of this tool is its contribution to a better understanding of the biological effects of dispersants and oil in the aquatic environment.


2001 ◽  
Vol 2001 (1) ◽  
pp. 461-466 ◽  
Author(s):  
Sy Ross ◽  
Ian Buist ◽  
Steve Potter ◽  
Randy Belore ◽  
Alun Lewis

ABSTRACT The Minerals Management Service (MMS), U.S. Department of the Interior, operates a wave tank facility in Leonardo, New Jersey known as OHMSETT (Oil and Hazardous Material Simulated Environmental Test Tank), which is used primarily for testing oil spill booms and skimmers. This paper summarizes two studies undertaken to examine the feasibility of testing dispersants at the facility as well. The first study included: (1) interfacial tension laboratory tests, (2) turbidity tests, (3) laboratory tests to evaluate filtering materials for removing dispersant and chemically dispersed oil, and (4) full-scale evaluation testing at OHMSETT. The results indicated that dispersant testing at OHMSETT could be done with good success if the testing program were carefully designed and implemented. It was determined that a number of dispersant tests could be conducted over several days, after which the tank water would have to thoroughly cleaned to remove dispersed oil (with a cellulose-based filter) and dispersant (with an activated carbon system). Following the feasibility study, the project moved to the second study, namely the design and validation of an experimental protocol for dispersant effectiveness testing at the facility. Full-scale tank work was conducted in April 2000. Preliminary results, provided in this paper, indicate that OHMSETT is an attractive facility for determining dispersant effectiveness.


2015 ◽  
Vol 105 ◽  
pp. 8-19 ◽  
Author(s):  
Marianne Frantzen ◽  
Bjørn Henrik Hansen ◽  
Perrine Geraudie ◽  
Jocelyn Palerud ◽  
Inger-Britt Falk-Petersen ◽  
...  

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