Centre for Environmental and Marine Studies

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Publications

Monitoring waterborne pathogens in surface and drinking waters : are water treatment plants (WTPs) simultaneously efficient in the elimination of enteric viruses and fecal indicator bacteria (FIB)?

Publication . Salvador, Daniel; Caeiro, Maria; Serejo, Fátima; Nogueira, Paulo Jorge; Carneiro, Rui Neves; Neto, Célia

Monitoring the quality of water is a requisite to prevent outbreaks related to waterborne diseases, predominantly caused by pathogens like enteric viruses, usually transmitted via the fecal-oral route. This study aimed to survey a group of enteric viruses (Enterovirus, Norovirus genogroups I and II, and hepatitis A virus) in two surface water sources of drinking water, also intending to evaluate the extent of their elimination in the two water treatment plants (WTPs) involved in drinking water production. Correlations between these viruses and fecal indicator bacteria (FIB) were also evaluated. Positive samples for viral RNA were recurrently found by reverse transcription quantitative PCR (RT-qPCR) and quantified, in genomic copies per liter (gc/L) of sampled water. Viral RNAs were detected in 14 out of 27 samples of surface water, and 21 out of 36 samples of drinking water, NoV II having been the most frequently detected in both (0–78.6 gc/L and 0–12.5 gc/L, respectively). Both WTPs showed variable efficacies in the elimination of viral RNA. Only one correlation was found with FIB, between NoV II and intestinal enterococci. These results recommend the monitoring of enteric viruses over time and their inclusion in the mandatory analysis of water quality.

2020Journal article

Open access

Assessment of the presence of Hepatitis E virus in surface water and drinking water in Portugal

Publication . Salvador, Daniel; Neto, Célia; Benoliel, Maria João; Caeiro, M. F.

Hepatitis E virus (HEV) is a non-enveloped single-stranded positive-sense RNA virus, belonging to the Hepeviridae family, resistant to environmental conditions, and transmitted by the consumption of contaminated water. This virus is responsible for both sporadic and epidemic outbreaks, leading to thousands of infections per year in several countries, and is thus considered an emerging disease in Europe and Asia. This study refers to a survey in Portugal during 2019, targeting the detection and eventual quantification of enteric viruses in samples from surface and drinking water. Samples positive for HEV RNA were recurrently found by reverse transcription quantitative PCR (RT-qPCR), in both types of matrix. The infectivity of these samples was evaluated in cultured Vero E6 cells and RNA from putative viruses produced in cultures evidencing cytopathic effects and was subjected to RT-qPCR targeting HEV genomic RNA. Our results evidenced the existence of samples positive either for HEV RNA (77.8% in surface water and 66.7% in drinking water) or for infectious HEV (23.0% in surface water and 27.7% in drinking water). These results highlight the need for effective virological control of water for human consumption and activities.

2020Journal article

Open access

Marine hazard assessment of soluble and nanostructured forms of the booster biocide DCOIT in tropical waters

Publication . Perina, Fernando; Ottoni, Cristiane; Santos, Juliana; Santos, Vithória; Silva, Mariana; Campos, Bruno; Fontes, Mayana; Santana, Debora; Maia, Frederico; Abessa, Denis; Martins, Roberto

The encapsulation of antifouling compounds, such as DCOIT (4,5-Dichloro-2-octylisothiazol- 3(2H)-one), in mesoporous silica nanocapsules (SiNC) has recently been demonstrated to be an eco-friendly alternative to decrease biocide toxicity towards marine non-target species. However, the lack of information on the chronic effects of such nanomaterials on non-target tropical species is critical for a more comprehensive environmental risk assessment. Thus, the present study aimed to assess the chronic toxicity and hazard of the soluble and encapsulated forms of DCOIT on neotropical marine species. Chronic tests were conducted with six ecologically relevant species. No effect concentration (NOEC) values were combined with NOEC values reported for tropical species to assess the hazard using the probabilistic approach to derive each predicted no effect concentration (PNEC). The SiNC-DCOIT was three- to ten-fold less toxic than soluble DCOIT. Probabilistic-based PNECs were set at 0.0001 and 0.0097 g DCOIT L􀀀1 for the biocide soluble and nanostructured forms, respectively. The immobilization of DCOIT into SiNC led to an 84-fold hazard decrease, confirming that the encapsulation of DCOIT into SiNC is a promising eco-friendly alternative technique, even in a chronic exposure scenario. Therefore, the present study will contribute to better management of the environmental risk of such innovative products in the tropical marine environment.

2023-03Journal article

Open access

Unraveling the mysteries of chrysomya albiceps (Diptera, Calliphoridae) : Morphology, potential distribution and forensic applications

Publication . Rodrigues-Filho, Sérgio; Rebelo, Maria Teresa

Blowflies, specifically Chrysomya albiceps, hold significant importance in several fields, including forensics, sanitary, veterinary sciences, and ecology. Despite being a well-studied species, there are still knowledge gaps regarding the interplay between C. albiceps and temperature, its practical application in forensic entomology, and the analysis of anatomical ultrastructures. This thesis aims to bridge these gaps by investigating the relationship between temperature and morphology, temperature and distribution, and providing practical insights into the temperature-biology relationship and the description of two anatomical ultrastructures of C. albiceps for forensic purposes. To achieve these objectives, we employed geometric morphometry techniques, machine learning algorithms, estimatesinvolving species biology and its association with temperature (such as Accumulated Degree Days - ADD), and scanning electron microscopy (SEM). The key findings can be summarized as follows: significant differences in wing shape exist between males and females, aiding in sex identification, and wing size exhibits a negative correlation with temperature. According to the model and the variables tested in this thesis, a substantial area of Europe is climatically suitable for C. albiceps. Among the variables examined, mean annual temperature and annual temperature range were found to be the best predictors of climatic suitability. Future projections indicate an increase in climate suitability due to temperature variations. The calculations involving ADD validate the potential use of C. albiceps as a forensic indicator in criminal investigations. SEM analysis revealed previously undocumented sensillae associated with the olfactory apparatus and a possible sexual dimorphism in the locomotor apparatus of C. albiceps. These findings underscore the abundance of unexplored possibilities for the study of C. albiceps. It is anticipated that these results would provide a theoretical foundation for future research endeavors, contributing to an enhanced understanding of the species for practical applications across various scientific domains.

2024-01Doctoral thesis

Open access

Dynamics and Causes of Sea Level Rise in the Coastal Region of Southwest Bangladesh at Global, Regional, and Local Levels

Publication . Ashrafuzzaman, Md.; Santos, Filipe; Dias, João Miguel; Cerdà, Artemi

Global greenhouse gas emissions have caused sea level rise (SLR) at a global and local level since the industrial revolution, mainly through thermal expansion and ice melting. Projections indicate that the acceleration of SLR will increase in the near future. This will affect coastal and deltaic populations worldwide, such as in Bangladesh, where almost half of the population resides in regions lower than 5 m above sea level. This study found three coastal tidal gauges and five deltaic gauge stations, which showed increases in SLR at greater rates than the regional and global averages. This research also used satellite altimetry data to analyze regional and global SLR averages in the recent past and the 21st century. There is a trend towards increasing sea level based on results from three tide gauge stations: Char Changa with 7.6 mm/yr, Hiron Point at 3.1 mm/yr from 1993 to 2019, and 14.5 mm/yr at Cox’s Bazar from 1993 to 2011. Based on the linear trend from these time frames, it is projected that SLR in Char Changa will increase by 228 mm from 2020 to 2050, and by 608 mm by 2100, at Hiron Point by 93 mm in 2050 and 248 mm by 2100, and at Cox’s Bazar by almost 435.7 mm by 2050, and more than 1162 mm by 2100. Based on an average from satellite altimeters, assuming a linear increase in SLR, the Bay of Bengal shows an increase of 0.4 mm compared to the global trend. Other river delta stations in the study area also show increasing SLR, specifically, at Kalaroa, Benarpota, Kaikhali, Tala Magura, and Elarchari. Kalaroa and Benarpota show the highest, with SLR of >40 mm/yr. It is also observed that increasing SLR trends are far higher than coastal tide gauges, indicating that physical processes in the delta region are affecting SLR, further contributing to either an increase in water volume/SLR or activating land subsidence. This is partly due to the subsidence of the delta as a result of natural and anthropomorphic effects, as well as an increase in Himalayan glacier melting due to global warming. This indicates that Bangladesh coastal areas will soon experience a far greater SLR than the rest of the Bay of Bengal or other global coastal areas.

2022Journal article

Open access