Modeling photosynthesis ofSpartina alterniflora(smooth cordgrass) impacted by the Deepwater Horizon oil spill using Bayesian inference

Abstract

To study the impact of the Deepwater Horizon oil spill on photosynthesis of coastal salt marsh plants in Mississippi, we developed a hierarchical Bayesian (HB) model based on field measurements collected from July 2010 to November 2011. We sampled three locations in Davis Bayou, Mississippi (30.375 • N, 88.790 • W) representative of a range of oil spill impacts. Measured photosynthesis was negative (respiration only) at the heavily oiled location in July 2010 only, and rates started to increase by August 2010. Photosynthesis at the medium oiling location was lower than at the control location in July 2010 and it continued to decrease in September 2010. During winter 2010-2011, the contrast between the control and the two impacted locations was not as obvious as in the growing season of 2010. Photosynthesis increased through spring 2011 at the three locations and decreased starting with October at the control location and a month earlier (September) at the impacted locations.Using the field data, we developed an HB model. The model simulations agreed well with the measured photosynthesis, capturing most of the variability of the measured data. On the basis of the posteriors of the parameters, we found that air temperature and photosynthetic active radiation positively influenced photosynthesis whereas the leaf stress level negatively affected photosynthesis. The photosynthesis rates at the heavily impacted location had recovered to the status of the control location about 140 days after the initial impact, while the impact at the medium impact location was never severe enough to make photosynthesis significantly lower than that at the control location over the study period. The uncertainty in modeling photosynthesis rates mainly came from the individual and micro-site scales, and to a lesser extent from the leaf scale.

Integrated effects of the Deepwater Horizon oil spill on nearshore ecosystems

“…Injury was estimated to occur over at least 563 km (350 miles) of shoreline in Louisiana mainland herbaceous salt marsh alone, based on the extent of observed shoreline and plant oiling conditions (Nixon et al , 2016 and the findings of injury to oiled mainland herbaceous plants (Hester et al 2016). NRDA findings of injury to wetland vegetation cover, photosynthesis, and biomass, particularly along the marsh edge (Table 1), were consistent with those found by other researchers (Lin & Mendelssohn 2012, Mishra et al 2012, Wu et al 2012, Khanna et al 2013, Shapiro et al 2016. Plant stem oiling (where oiling occurred over more than 90% of the length of the stem), soil and shoreline oiling, associated response actions, and loss of nearshore oyster cover (Gibeaut et al 2015, Roman 2015, Silliman et al 2016, Powers et al 2017.…”

Vegetation Impact and Recovery from Oil-Induced Stress on Three Ecologically Distinct Wetland Sites in the Gulf of Mexico

“…The objective of this study is to compare the impact of the BP-DWH oil spill on wetland vegetation and monitor recovery in the following year across three diverse ecosystems in the MDP. Several studies have documented the impact from the BP spill for the gulf wetlands, but the majority of these studies have focused on a single marsh vegetation species or a single site in the gulf [5,17,[23][24][25]. We wanted to compare the effect of the BP-DWH oil spill across multiple ecosystems in the gulf as well as evaluate recovery of live foliar canopy a year later.…”

Recent hybridization and allopolyploidy reprogrammedSpartinamicroRNA expression under xenobiotic induced stress

“…Micro-RNAs expression levels in S. x townsendii and S. anglica were also compared to those of MPV under phenanthrene-induced stress to identify phenanthrene-responsive miRNAs candidates whose expression was affected by interspecific hybridization and/or genome doubling. Moreover, DE miRNAs under phenanthrene-induced stress between the maternal parent (which exhibits xenobiotic resilience following the Deepwater Horizon oil spill; see Wu et al ., 2012; Robertson et al ., 2017; Alvarez et al ., 2018) and the paternal parent were retained.…”

“…are exposed to environmental pollution from anthropogenic activities like oil spills (Lin & Mendelssohn, 2012; Lin et al ., 2016; Robertson et al ., 2017), which include organic pollutants compounds from the PAH family. Interestingly, resilience abilities reported in S. alterniflora populations exposed to crude oil suggest efficient tolerance abilities to such environmental pollutants (Wu et al ., 2012; Alvarez et al ., 2018), that could be used for green remediation. Recently, comparative physiological analyses of phenanthrene (one of major PAHs in crude oil; Liu et al ., 2012) treated Spartina leaves between parental species and S. anglica reported enhanced tolerance abilities to PAHs following allopolyploidy (Cavé-Radet et al ., 2019b).…”