Radiolabeled polycyclic aromatic hydrocarbons (PAH) containing up to three rings, including naphthalene, methylnaphthalenes, and phenanthrene, were degraded (measured by 14CO2 production) in water samples from both Narragansett Bay and southeastern United States. Higher weight PAH, including benz[a]anthracene, chrysene, fluorene, and anthracene, showed little, if any, degradation in water but were readily degraded when added to sediment–water slurries. In areas with low levels of petroleum in the water or sediment there was a lag before appreciable degradation began, and the rate of degradation fitted a first-order equation. Half-lives, calculated for the various PAH added to water or sediment–water slurries, were very low during winter months; [14C]methylnaphthalene added to water from Skidaway River, Georgia, in January (8 °C) was 57 d, while in September (28 °C) it was 3 d. PAH added to sediments or water from oil-treated areas or mesocosms were rapidly degraded with no lag phase and the degradation rate was linear. [14C]Methylnaphthalene added to water from control and oiled mesocosms in May (10 °C) had half-lives of 300 and 5 d, respectively. We plotted the changes in turnover times with changes in the concentration of PAH and calculated the natural turnover times and Vmax for PAH added to water or sediment from the oiled mesocosms. When [14C]dimethylbenz[a]anthracene was incubated in water in the dark no degradation occurred, but when exposed to sunlight, 0.3% was mineralized in 18 h. In addition, a variety of photooxidation products were produced. The production of 14CO2 in the light was due to microbial degradation of photooxidation products of [14C]dimethylbenz[a]anthracene.

Core Ideas Plant tissue tests are interpreted using yield as a metric. Turfgrass value is commonly measured using quality. Reference ranges identify “normal” nutrient ranges by using turf quality as a metric. Reference ranges should be considered as an alternative tissue test interpretation. Tissue testing is a common practice in turfgrass management and is intended to guide nutrient applications. However, standard interpretations are a product of agricultural cropping systems and use yield as the primary metric. Yield is often of little importance in turfgrass systems and, thus, traditional test interpretations may be of little value. Reference ranges interpret test results by first defining a ‘normal’ population followed by analysis and determination of the 95% confidence interval for each nutrient. Moreover, reference ranges can be determined for cultivar, season, and age‐specific populations, which would result in a more precise interpretation and nutrient recommendation for turf managers. Because reference ranges use the accepted turf quality metric, reference ranges should be considered as an alternate option to traditional turfgrass tissue test interpretations.