Climate change 2014 - Synthesis Report

The science of the total environment

Distribution and importance of microplastics in the marine environment: A review of the sources, fate, effects, and potential solutions

The package fitdistrplus provides functions for fitting univariate distributions to different types of data (continuous censored or non-censored data and discrete data) and allowing different estimation methods (maximum likelihood, moment matching, quantile matching and maximum goodness-of-fit estimation). Outputs of fitdist and fitdistcens functions are S3 objects, for which specific methods are provided, including summary, plot and quantile. This package also provides various functions to compare the fit of several distributions to the same data set and can handle to bootstrap parameter estimates. Detailed examples are given in food risk assessment, ecotoxicology and insurance contexts.

fitdistrplus: An R Package for Fitting Distributions

Recent advances in molecular biology have extended our understanding of the metabolic processes related to microbial transformation of petroleum hydrocarbons. The physiological responses of microorganisms to the presence of hydrocarbons, including cell surface alterations and adaptive mechanisms for uptake and efflux of these substrates, have been characterized. New molecular techniques have enhanced our ability to investigate the dynamics of microbial communities in petroleum-impacted ecosystems. By establishing conditions which maximize rates and extents of microbial growth, hydrocarbon access, and transformation, highly accelerated and bioreactor-based petroleum waste degradation processes have been implemented. Biofilters capable of removing and biodegrading volatile petroleum contaminants in air streams with short substrate-microbe contact times ( 2 S and sulfoxides from petrochemical waste streams. Microbes also have potential for use in removal of nitrogen from crude oil leading to reduced nitric oxide emissions provided that technical problems similar to those experienced in biodesulfurization can be solved. Enzymes are being exploited to produce added-value products from petroleum substrates, and bacterial biosensors are being used to analyze petroleum-contaminated environments.

Recent Advances in Petroleum Microbiology

Microplastic particles (MPPs; <5 mm) are found in skin cleansing soaps and are released into the environment via the sewage system. MPPs in the environment can sorb persistent organic pollutants (POPs) that can potentially be assimilated by organisms mistaking MPPs for food. Amphipods (Allorchestes compressa) exposed to MPPs isolated from a commercial facial cleansing soap ingested ≤45 particles per animal and evacuated them within 36 h. Amphipods were exposed to polybrominated diphenyl ether (PBDEs) congeners (BDE-28, -47, -99, -100, -153, -154, and -183) in the presence or absence of MPPs. This study has demonstrated that PBDEs derived from MPPs can be assimilated into the tissue of a marine amphipod. MPPs reduced PBDE uptake compared to controls, but they caused greater proportional uptake of higher-brominated congeners such as BDE-154 and -153 compared to BDE-28 and -47. While MPPs in the environment may lower PBDE uptake compared to unabsorbed free chemicals, our study has demonstrated they can transfer PBDEs into a marine organism. Therefore, MPPs pose a risk of contaminating aquatic food chains with the potential for increasing public exposure through dietary sources. This study has demonstrated that MPPs can act as a vector for the assimilation of POPs into marine organisms.

Assimilation of polybrominated diphenyl ethers from microplastics by the marine amphipod, allorchestes compressa

The prevalence of microplastics (<5 mm) in natural environments has become a widely recognized global problem. Microplastics have been shown to sorb chemical pollutants from their surrounding environment, thus raising concern as to their role in the movement of these pollutants through the food chain. This experiment investigated whether organic pollutants sorbed to microbeads (MBs) from personal care products were assimilated by fish following particle ingestion. Rainbow fish (Melanotaenia fluviatilis) were exposed to MBs with sorbed polybrominated diphenyl ethers (PBDEs; BDE-28, -47, -100, -99, -153, -154, -183, 200 ng g(-1); BDE-209, 2000 ng g(-1)) and sampled at 0, 21, 42, and 63 days along with two control treatments (food only and food + clean MBs). Exposed fish had significantly higher Σ8PBDE concentrations than both control treatments after just 21 days, and continued exposure resulted in increased accumulation of the pollutants over the experiment (ca. 115 pg g(-1) ww d(-1)). Lower brominated congeners showed the highest assimilation whereas higher brominated congeners did not appear to transfer, indicating they may be too strongly sorbed to the plastic or unable to be assimilated by the fish due to large molecular size or other factors. Seemingly against this trend, however, BDE-99 did not appear to bioaccumulate in the fish, which may be due to partitioning from the MBs or it being metabolized in vivo. This work provides evidence that MBs from personal care products are capable of transferring sorbed pollutants to fish that ingest them.

Chemical Pollutants Sorbed to Ingested Microbeads from Personal Care Products Accumulate in Fish.

Salinity levels are rising in many freshwater environments, yet there are few direct measurements of salinity tolerance of organisms likely to be salt sensitive. The relative salinity tolerance to artificial seawater of macroinvertebrates from the Barwon River in Victoria, Australia, was assessed by measuring the 72-h lethal concentrations required to kill 50% of individuals (LC50). LC50 values ranged from an electrical conductivity of 5.5 to 76 mS cm–1 (mean 31 mS cm–1, n = 57) and followed a log-normal distribution. The most salt-sensitive groups tested were Baetidae (LC50 value range: 5.5–6.2 mS cm–1), Chironomidae (10 mS cm–1) and several soft-bodied non-arthropods (Oligochaeta, Gastropoda, Nematomorpha, Tricladida and Hirudinea; 9–14 mS cm–1). Other groups, from least to most tolerant, were non-baetid Ephmeroptera (>12.6–15 mS cm–1), Plecoptera (>12.6–>20 mS cm–1), Trichoptera (9–>26 mS cm–1), Corixidae (18–26 mS cm–1), non-corixid Hemiptera (33–44 mS cm–1), Coleoptera (19–54 mS cm–1), Hydracarina (39 mS cm–1) and Odonata (30–55 mS cm–1), and macrocrustaceans (Decapoda, Isopoda and Amphipoda; 38–76 mS cm–1).

Relative salinity tolerance of macroinvertebrates from the Barwon River, Victoria, Australia

Do laboratory salinity tolerances of freshwater animals correspond with their field salinity

SUMMARY Increased salinity in rivers and streams is a serious environmental
concern, and in Australia there is growing information about the acute
tolerances to salinity for freshwater macroinvertebrates, but much less
information about chronic and sub-lethal tolerances. The effects of increased
salinity on the growth and survival of two mayflies, Cloeon sp. and
 Centroptilum sp. and one midge Chironomus sp. are reported.
In both mayfly species survival was variable. Complete mortality was observed
in salinities with electrical conductivity of 10 mS cm –1 and
higher. Salinities causing chronic mortality in mayflies were measured as
21-day LC 50 , and ranged from 0.90 to 2.7 mS cm –1 .
Growth rates were not significantly different between treatments. In
 Chironomus , salinity affected the mean number emerging as flying
adults as well as the time to emergence. An inverted `U9 shape response was
observed for percentage emergence, with the greatest numbers emerging at
intermediate salinities (0.65–5.0 mS cm –1 ). No
emergence occurred at salinities of 20 mS cm –1 and higher.
Time to emergence was delayed by 15–88% with increased salinity, however
the size of emerged adults was the same for all treatments. Growth rates were
reduced with increased salinity, showing a slow, steady reduction up to 10 mS
cm –1 then a steep decline between 10 and 15 mS
cm –1 . The implications of altered growth rates and changes in
developmental times are discussed. This study illustrates the variability in
responses to increased salinity, and highlights the need to continue studying
sub-lethal and chronic exposures in a range of freshwater invertebrates, in
order to predict impacts of salinisation on freshwater biodiversity.

/pdf/sub-lethal-and-chronic-salinity-tolerances-of-three-3vabno8ajq.pdf

Sub-lethal and chronic salinity tolerances of three freshwater insects:Cloeon sp. and Centroptilum sp. (Ephemeroptera: Baetidae)and Chironomus sp. (Diptera: Chironomidae)

Dayanthi Nugegoda

Papers

Assimilation of polybrominated diphenyl ethers from microplastics by the marine amphipod, allorchestes compressa

Chemical Pollutants Sorbed to Ingested Microbeads from Personal Care Products Accumulate in Fish.

Relative salinity tolerance of macroinvertebrates from the Barwon River, Victoria, Australia

Do laboratory salinity tolerances of freshwater animals correspond with their field salinity

Sub-lethal and chronic salinity tolerances of three freshwater insects:Cloeon sp. and Centroptilum sp. (Ephemeroptera: Baetidae)and Chironomus sp. (Diptera: Chironomidae)