Microplastics are among the major environmental problems to be addressed because it is beginning to affect food chains and is also reaching human populations. The present study investigated the size, ...color, shape and abundance of microplastics in juvenile silversides (Atheriniformes) belonging to the edible species Odontesthes bonariensis, Odontesthes nigricans and Odontesthes argentinensis from shallow coastal waters. While 100 % of the sampled individuals presented microplastics in stomach contents, fibers were 95 %. There is a correlation between the size of the individuals and the maximum particle size ingested ranging from 0.2 to 1.2 mm. There is no significant difference in the number of particles ingested per individual. The plastic particles had a lower density than seawater, which is why they floated on the surface. These results imply that the protected areas of large ocean currents increase the exposure of local fauna to microplastics increasing the risk of ingestion of PMs.
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Microplastics are one of the major environmental issues that need to be addressed because they are starting to impact food chains and are also affecting human populations. The size, colour, form, and ...abundance of microplastics in young blennies of the species Eleginops maclovinus were examined in the current study. While the stomach contents of 70 % of the studied individuals contained microplastics, 95 % of them included fibres. Individual size and the largest particle size that can be eaten, which ranges between 0.09 and 1.5 mm present no statistical correlation. The quantity of particles taken in by each individual does not change with size. The most present microfibers colours were blue and red. Sampled fibres were analysed with FT-IR and no natural fibres were detected, proving the synthetic origin of the detected particles. These findings suggest that protected coastlines create conditions that favour the encounter of microplastics increasing local wildlife exposure to microplastics, raising the danger of their ingestion with potential physiological, ecological, economical and human health consequences.
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•Benthic fishes ingested microplastics independently of the size.•Plastics were present in 70 % of the studied individuals.•Microfibers were the predominant for of plastic in gut content.
Polybrominated diphenyl ethers (PBDEs) are among the emerging contaminants that have been traced in almost all environmental compartments for the past 30 years. Their continued application as ...flame-retardant additives, persistence in nature due to fluorine groups, global atmospheric transport, and analytical challenges due to interferences and different properties of congeners indicate the urgent need of finding solutions to their use. The increasing level of PBDEs in the environment and especially human tissues is alarming due to their potential neurological effects, cancer proliferation, and thyroid hormone imbalance. Therefore, strict regulations need to be applied in all countries to control the PBDEs production consumption and disposal into the environment. Studies have shown that conventional wastewater treatment plants are unable to degrade PBDEs resulting in the transport of 60-90% of PBDEs to soil through biosolids application. On the other hand, advanced treatment processes, such as ultraviolet light, advanced oxidation, and photocatalytic degradation showed promising potential for removing PBDEs from wastewater (70-100% degradation efficiency). PBDEs can be replaced by natural flame retardants, such as nanoclay or new polymers, such as bishydroxydeoxybenzoin which have no environmental or health problems compared to PBDEs.
The historical processes that have influenced the genetic structure of many species are often associated with environmental changes of the Pleistocene glacial cycles. These climate changes involve ...temperature oscillation, marine currents and loss of coastal habitats, which could have affected the abundance and geographic distribution of marine species in temperate coastal habitats. In this work, a 552-bp mtDNA fragment of COI locus of 92 individuals was sequenced to analyze the genetic structure of the limpet
Siphonaria lessoni
. Individuals were collected on the intertidal coast of the Southern Atlantic (Mar del Plata, San Antonio Oeste, Puerto Madryn and Ushuaia in Argentina) and the Southern Pacific (Valdivia and Valparaíso in Chile).
S. lessoni
displayed two distinct lineages that were nearly reciprocally monophyletic between the Atlantic and Pacific coasts. AMOVA tests revealed the existence of strong population genetic structure. The Pacific coasts yielded more haplotypes and polymorphic sites as well as higher haplotype and nucleotide diversity than the Atlantic clade did. Both Tajima’s
D
and Fu’s
F
s
were significant and negative, suggesting that limpet populations are in population expansion or have recently expanded. Accordingly, the haplotype network for each clade showed a star-like phylogeographic pattern. From IMa analysis, the divergence time between Pacific and Atlantic populations was 100,000–1,000,000 ybp with gene flow occurring from Pacific to Atlantic populations. The Bayesian Skyline analysis revealed an older coalescence in the Pacific clade (30,000–300,000 ybp) as compared to that in the Atlantic clade (4,000–40,000 ybp). This work reports evidence of Pacific–Atlantic geographic isolation with asymmetric migration, which is probably related to changes in sea level and temperature due to the extended glaciation periods that occurred in the region throughout the Pleistocene.
Wastewater (WW) for irrigation and application of biosolids in soil is becoming important as it is going to become very common in the near future. By 2050, the world is going to have four billion ...people living in water-scarce countries, making it a norm of freshwater for the cities and WW for agriculture. Further, biosolids might still be used as green biofertilizers for soils, if they are improved from an ecological point of view. However, application of biosolids in soil is argued because of the amount of organic pollutants that compromise the dynamic equilibrium of the biological systems. Therefore, information on the concentration, behavior, and cycling of organic pollutants as well as their possible degradation pathways is needed to predict, prevent, and remediate these pollutants from different sources including WW and biosolids. Among the group of organic pollutants, emerging contaminants (ECs) enter into the soil with the irrigation water from treated effluents and fertilization by biosolids. Quantification of ECs from WW and biosolids is of main importance to predict the toxic effects of WW effluents and sludge. Moreover, their incorporation into vegetables through irrigation and their magnification through natural food webs have been proved and must be monitored. This review presents information on the different sources of emerging contaminants and linking with the ecological effects they produced by reacting in the environment during various applications of WW and biosolids in soil. The available methods for analysis and quantification of ECs in different matrices, such as WW and biosolids, are also presented.
The distribution of butyltins (BTs) and polycyclic aromatic hydrocarbons (PAHs) were studied in surface sediments to assess how relevant is Mar del Plata port (Argentina) as a source of contamination ...to the surrounding environments. Within the port, TBT concentrations ranged from 24.2 to 150 ng Sn g
−1
and PAHs (Σ16) from 180 to 17,094 ng g
−1
. At the surrounding beaches, PAHs were detected at low concentrations and TBT concentrations reached 10.9 ng Sn g
−1
. Although those low levels indicate that the Port might not be an important source of contamination to the surrounding beaches, the very low TOC content and the coarse grain size of the beaches sediments could explain the sedimentary levels. The results show a reduction in TBT levels in Mar del Plata port after national and international use restrictions of TBT-based antifouling paints.
Pampean creeks were evaluated in the present study as potential land-based sources of PCB marine contamination. Different carbon and nitrogen sources from such creeks were analysed as boosters of PCB ...bioaccumulation by the filter feeder bivalve Brachidontes rodriguezii and grazer limpet Siphonaria lessoni. Carbon of different source than marine and anthropogenic nitrogen assimilated by organisms were estimated through their C and N isotopic composition. PCB concentration in surface sediments and mollusc samples ranged from 2.68 to 6.46 ng g−1 (wet weight) and from 1074 to 4583 ng g−1 lipid, respectively, reflecting a punctual source of PCB contamination related to a landfill area. Thus, despite the low flow of creeks, they should not be underestimated as contamination vectors to the marine environment. On the other hand, mussels PCB bioaccumulation was related with the carbon source uptake which highlights the importance to consider this factor when studying PCB distribution in organisms of coastal systems.
•PCBs burden of intertidal sediments and mollusks from creeks outfalls were studied.•The influence of organic materials on mollusks PCB accumulation was evaluated.•PCB contamination from land based sources related to a landfill area was recorded.•Creeks act as a contamination vector from land based sources.•Different carbon source consumed by mussels enhanced their PCB accumulation.
Imposex is a widespread phenomenon in marine molluscs, documented in more than 120 gastropod species. Its occurrence is explained as a result of an anti-fouling paint compound called TBT ...(tributyltin), whose presence is related to high marine traffic. In order to study if imposex was occurring in the SW Atlantic, specimens of two common gastropods Buccinanops monilifer and Adelomelon brasiliana were collected during the five last months of 2000 from Mar del Plata harbor (Lat. 37 degree 50' S) in a high boating activity area.
•Cyanotoxins removal are dependent on environmental parameters, mainly pH and Natural Organic Matters.•Chlorination and ozonation employed for cyanotoxin treatment may breach guideline ...values.•Membrane technology and photocatalysis operation involves high energy and maintenance.•Specific reaction pathway shifts oxidation process more towards sustainable approach.
Over the years, various physicochemical treatment processes, such as photocatalysis, membrane technology, ozonolysis and chlorination have been tested at laboratory and pilot scale for the treatment of various cyanotoxins. Most of these treatment processes are also being commonly practiced in a drinking water treatment plants (DWTPs). However, the degree of treatment widely varies among cyanotoxin variants and is mainly governed by the source water characteristics, operational parameters (temperature, pH, cyanotoxin level) which changes continuously in a DWTPs. Other common elements present in raw water, such as natural organic matter (NOMs), residual nutrients and metal ions shows competitive behaviour with the cyanotoxins. Thus, a high demand in input energy is needed for unit operations, such as photocatalysis, reverse osmosis membrane and excess chemical requirement in terms of ozone, permanganate and chlorine (for ozonation and chlorination) which can breach the guidelines and increase the toxicity level. This review provides an insight into the effectiveness of major physico-chemical operations from simple to the advanced treatment level for the removal of different cyanotoxins along with their limitations and challenges in a DWTP. The goal of this review is to provide information on the possible reaction mechanism involved in the cyanotoxin treatment, accounting mainly for the toxicity, modifications in the process that happened over the years and the process feasibility. In future, hybrid technique assisted by UV, peroxides, among others promises to assist photocatalytic, ozonation and chlorination to undergo efficient cyanotoxin removal with reduced toxicity level. Also, persistence cyanotoxins, such as anatoxin and saxitoxin need further study.
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