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Spatial-temporal genome damaging in the blue crab Cardisoma guanhumi as ecological indicators for monitoring tropical estuaries Full text
2020
Falcão, C.B.R. | Pinheiro, M.A.A. | Torres, R.A. | Adam, M.L.
In this study, to better our understanding of the current state of conservation of Cardisoma guanhumi and its habitats, we evaluated the potential spatio-temporal genomic damage of this species across five estuaries in Brazil. The experiment was performed over two consecutive years, and the sampling was performed in the winter and summer seasons. Two genetic tests — micronucleus test and comet assay — were used to quantify the DNA damage. Unlike in the summers and in the winter of 2013, in the winter of 2012 a significant increase was noted in the frequency of micronucleated cells and genomic damage index. The occurrence of genomic damage coincided with the arrival of the harsh winter of 2012 as the water sourced from the coastal rivers significantly affected the estuarine species under study. Our results confirmed that this species was resilient to the atypical climatic conditions, which facilitated the generation of excessive waste.
Show more [+] Less [-]Nutrient thresholds to protect water quality and coral reefs Full text
2020
Houk, Peter | Comeros-Raynal, Mia | Lawrence, Alice | Sudek, Mareike | Vaeoso, Motusaga | McGuire, Kim | Regis, Josephine
Establishing nutrient thresholds to protect coral reefs is difficult because water quality is dynamic and shifts with many environmental factors. We examined the contribution of natural and human factors in predicting water quality at the base of 34 streams on a high tropical Pacific island. Mixed regression models revealed that rainfall, sea-surface temperature, and windspeed were fixed factors predicting dissolved inorganic nitrogen (DIN) concentrations at the base of all watersheds. In contrast, human influences were captured as random components of variation associated with site-based differences. The novel modeling approach using temporal and spatial data provided daily-loading simulations that were used to evaluate exceedance criteria, defined as the percent of time each watershed exceeded a suite of DIN thresholds. Exceedance criteria were considered alongside biological data to recommend a 0.1 to 0.15 mg l⁻¹ benchmark to protect coastal water quality and coral reefs surrounding Tutuila, American Samoa.
Show more [+] Less [-]Remote sensing of coastal algal blooms using unmanned aerial vehicles (UAVs) Full text
2020
Cheng, K.H. | Chan, S.N. | Lee, Joseph H.W.
The explosive growth of phytoplankton under favorable conditions in subtropical coastal waters can lead to water discolouration and massive fish kills. Traditional water quality monitoring relies on manual field sampling and laboratory analysis of chlorophyll-a (Chl-a) concentration, which is resources intensive and time consuming. The cloudy weather of Hong Kong also precludes using satellite images for algal blooms monitoring. This study for the first time demonstrates the use of an Unmanned Aerial Vehicle (UAVs) to quantitatively map surface water Chl-a distribution in coastal waters from a low altitude. An estimation model for Chl-a concentration from visible images taken by a digital camera on a UAV has been developed and validated against one-year field data. The cost-effective and robust technology is able to map the spatial and temporal variations of Chl-a concentration during an algal bloom. The proposed method offers a useful complement to traditional field monitoring for fisheries management.
Show more [+] Less [-]Characterisation of an unexplored group of microplastics from the South China Sea: Can they be caused by macrofaunal fragmentation? Full text
2020
Po, Beverly Hoi-Ki | Lo, Hoi-Shing | Cheung, Siu-Gin | Lai, Keng-Po
Research on plastics fragmentation is important for the estimation of amount of microplastics but the biological causes for fragmentation have not been acknowledged. From microplastics collected in the beaches of Hong Kong, we revealed an abnormal type of fragment which has not been reported before. These fragments, composing about 6% of the microplastics (pellet, foam, bead, fragment) collected, were interestingly triangular in shape with at least two of the three sides being characteristically straight and resembling a cut made by compression. Objective observations have distinguished these “trimmed triangular fragments” to those triangular fragments that were fractured randomly. By comparing with additional evidence, we proposed that these trimmed fragments were the daughter pieces of macrofaunal biting. If this was so, there would be wide implications on fragmentation modeling studies for microplastics since active biting of large plastic debris has generally not been considered as a factor of plastics fragmentation.
Show more [+] Less [-]Evaluation of metal pollution-induced biological effects in Chinese shrimp Fenneropenaeus chinensis by NMR-based metabolomics Full text
2020
Lu, Zhen | Wang, Shuang | Ji, Chenglong | Shan, Xiujuan | Wu, Huifeng
Metal pollution in Laizhou Bay along the Bohai Sea in China has been posing a risk on fishery species and hence may affect seafood quality. In this work, shrimps Fenneropenaeus chinensis were sampled from three sites, namely, a reference (site 6334) and two metal-polluted (sites 6262 and 7262) sites, located in Laizhou Bay. The metal concentrations in shrimp muscle tissues were tested using the ICP-MS technique. The Cr and Cu concentrations were the highest in the shrimp samples from site 7262, exceeding the national seafood safety standard Ⅱ, and the As concentration was much higher than the national seafood safety standard Ⅲ. NMR-based metabolomics indicated that metal pollution induced oxidative and immune stresses, damaged the muscular structure, and disrupted energy metabolism in shrimps at sites 6262 and 7262, in particular disturbed osmotic regulation in shrimps at site 7262. Glycine and serine could serve as biomarkers for Cd in F. chinensis.
Show more [+] Less [-]Influence of Noise on Patient Recovery Full text
2020
Loupa, Glykeria
PURPOSE OF REVIEW: The present review aims to highlight the noise effects on the patients’ well-being and by inference on their recovery, during their hospitalization, and also the effectiveness of applied interventions to reduce noise in the health care environment. RECENT FINDINGS: Key findings reported in relevant studies and conducted during the last 4 years are as follows: (a) noise continues to be above guideline values in health care facilities; (b) noise can disturb the sleep of the patients, can affect their rest and the communication between patients/staff/visitors, and finally can affect the staff effectiveness; (c) interventions to reduce the noise are promising but not well proven; and (d) the derived conclusions about the relationship between noise and the healing process are made indirectly and not by measurable patients’ physical parameters. The pathways that theoretically connect noise and the healing of the patients are numerous and still unclear. An extensively examined pathway infers that noise can disturb sleep and thus may prevent the patient’s recovery. Other pathways that relate noise to the recovery of the inpatients remain unknown, such as the aggravation/degradation of measureable physical parameters or the re-hospitalization due to noise, or the effect of the low-frequency noise. A protocol to conduct noise monitoring is required, as well as validated questionnaires, to examine the inpatient’s subjective perceptions for their acoustic environment. This may lead to comparable results among the relevant studies and hence to robust interventions for the improvement of the noise environment for hospitalized patients.
Show more [+] Less [-]Storm-induced sediment resuspension in the Changjiang River Estuary leads to alleviation of phosphorus limitation Full text
2020
Wu, Mengfan | Yang, Fuxia | Yao, Qingzhen | Bouwman, A. F. | Wang, Panpan
This paper presents an incubation experiment with sediment cores from the Changjiang Estuary Mud Area (CEMA) to quantify the release of nutrients due to simulated resuspension. The results show that except for nitrate (NO₃⁻-N), phosphate (PO₄³⁻-P), ammonium (NH₄⁺-N), nitrite (NO₂⁻-N) and silicate (SiO₃²⁻-Si) were released from the sediment to the overlying water, primarily due to desorption (P), dissolution (SiO₃²⁻-Si) and mineralization (NH₄⁺-N) with only minor direct contributions from the sediment pore water. The significant release of nutrients by resuspension and subsequent processes can alleviate the phosphorus and silicon limitation in water bodies, enhance the growth of phytoplankton, and thus promote the oxygen consumption and ultimately lead to hypoxia. The results of this study are highly relevant for many coastal areas in other parts of the world with large amounts of stored organic matter and nutrients in sediments and frequent perturbation by storm events.
Show more [+] Less [-]Novel hybrid methods applied for spatial prediction of mercury and variable selection of trace elements in coastal areas of USA Full text
2020
Sakizadeh, Mohammad
This study was concerned with spatial analysis of mercury (Hg) in sediment samples of the USA coastal areas using more accurate and stable hybrid approaches compared to the conventional methods. An ensemble of simulated annealing along with least angle regression (SA-LAR) was applied for selection of predictors in spatial analysis. The latest algorithm was efficient with resultant RMSE and R² of 0.066 and 0.705 compared to 0.099 and 0.571 for the traditional method of recursive feature elimination (RFE) approach. Using Cu, Pb and As as selected variables, it was tried to improve the spatial forecasting of Hg with either a hybrid of generalized boosted regression and ordinary kriging (GBROK) or inverse distance weighting (GBRIDW). According to the results, the variance explained by cross validation (VECV) was improved from 7.52% and 9.76% for IDW and OK to 40.41% and 41.94% for the GBRIDW and GBROK methods, respectively.
Show more [+] Less [-]Can we shop ourselves to a clean sea? An experimental panel approach to assess the persuasiveness of private labels as a private governance approach to microplastic pollution Full text
2020
Misund, Andreas | Tiller, Rachel | Canning-Clode, João | Freitas, Mafalda | Schmidt, Jörn O. | Javidpour, Jamileh
In this study, we conducted an experimental panel survey in Norway, Germany and Portugal to explore consumers' willingness to pay more for products that are certified microplastic free. This is placed within the context of private certification schemes and private governance as mechanisms to increase consumer conscientiousness, establish a higher environmental standard in terms of microplastic and reduce marine pollution. We find that consumers in general are very conscious about the issue, would generally prefer products that are microplastics free, but would seldom choose these when there is a price premium on the label. This had a geographical offset though, with the results aligning with that of political trust in the nation, with Norwegians being less likely to purchase items with price premiums for private governance labels, and Portugal being most likely to – even with a price premium.
Show more [+] Less [-]Debris ingestion and nutritional niches in estuarine and reef green turtles Full text
2020
Machovsky-Capuska, Gabriel E. | Andrades, Ryan | Santos, Robson Guimarães
Little attention has been drawn toward the effects of marine debris ingestion in relation to nutrient acquisition and fitness consequences. We tested whether anthropogenic debris ingestion influence the nutritional niches of endangered green turtles (Chelonia mydas) in estuarine and reef habitats on the Brazilian coast. Our results showed that estuarine turtles consumed diets with lower proportional wet mass composition of protein (P) and water (W) than their reef conspecifics. The amounts of debris, mostly plastics, retrieved from the digestive tracts of estuarine turtles were higher compared with those individuals from reefs. The realized nutritional niche from estuarine turtles was subject to the debris density in the environment, lack of benthic food resources available and the surface foraging behavior, likely preventing them from reaching their nutritional goals and resulting in lower fitness. The study provides critical information for the management and conservation of ecologically threatened individuals, populations, and their natural habitats.
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