Laboratory testing protocol for the impact of dispersed petrochemicals on seagrass

• Published in: Marine pollution bulletin Vol. 64; no. 11; pp. 2421 - 2427
• Main Authors: Wilson, K.G., Ralph, P.J.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2012
• Subjects: chlorophyll; Chlorophyll - metabolism; Chlorophyll a fluorescence; Crude oil; Dispersant; Fuel oil; fuel oils; gas chromatography-mass spectrometry; hydrocarbons; Hydrocarbons - toxicity; Laboratories; leaves; Marine; oil spills; petrochemicals; petroleum; Petroleum - toxicity; Photosynthesis - drug effects; photosystem II; seagrasses; testing; Toxicity Tests - methods; Toxicity Tests - standards; Water Pollutants, Chemical - toxicity; water pollution; Zostera; Zostera muelleri; Zosteraceae - drug effects; Zosteraceae - physiology; Dispersant; Chlorophyll a fluorescence; Zostera muelleri; Crude oil; Fuel oil
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2012.08.004

► Seagrass were exposed to dispersed and non-dispersed crude and fuel oil. ► Dispersed oil led to significant reductions in photosynthetic health of seagrass. ► Non-dispersed oil resulted in only minor reductions in seagrass health. ► Testing protocol developed enables rapid comparisons of oil spill mitigation options. To improve the effectiveness of oil spill mitigation, we developed a rapid, logistically simple protocol to detect petrochemical stress on seagrass. Sections of leaf blades from Zostera muelleri subsp. capricorni were exposed to the water accommodated fraction (WAF) of non-dispersed and dispersed Tapis crude oil and fuel oil (IFO-380) for 5h. Photosynthetic health was monitored by assessing changes in effective quantum yield of photosystem II (ΔF/Fm′) and chlorophyll a pigment concentrations. Loss of total petroleum hydrocarbons (TPH) was measured using an oil-in-water fluorometer, whilst GC–MS analyses quantified the hydrocarbon components within each treatment. Few significant differences were detected in the chlorophyll a pigment analyses; however, ΔF/Fm′ appeared sensitive to petrochemical exposure. Dispersing both types of oil resulted in a substantial increase in the TPH of the WAF and was generally correlated with a greater physiological impact to the seagrass health, compared with the oil alone.