Publications by authors named "Mauricio A Urbina"

50 Publications

Environmental determinants of COVID-19 transmission across a wide climatic gradient in Chile.

Sci Rep 2021 May 10;11(1):9849. Epub 2021 May 10.

Unidad de Cambio Climático y Medio Ambiente, Instituto Iberoamericano de Desarrollo Sostenible, Universidad Autónoma de Chile, Temuco, Chile.

Several studies have examined the transmission dynamics of the novel COVID-19 disease in different parts of the world. Some have reported relationships with various environmental variables, suggesting that spread of the disease is enhanced in colder and drier climates. However, evidence is still scarce and mostly limited to a few countries, particularly from Asia. We examined the potential role of multiple environmental variables in COVID-19 infection rate [measured as mean relative infection rate = (number of infected inhabitants per week / total population) × 100.000) from February 23 to August 16, 2020 across 360 cities of Chile. Chile has a large climatic gradient (≈ 40º of latitude, ≈ 4000 m of altitude and 5 climatic zones, from desert to tundra), but all cities share their social behaviour patterns and regulations. Our results indicated that COVID-19 transmission in Chile was mostly related to three main climatic factors (minimum temperature, atmospheric pressure and relative humidity). Transmission was greater in colder and drier cities and when atmospheric pressure was lower. The results of this study support some previous findings about the main climatic determinants of COVID-19 transmission, which may be useful for decision-making and management of the disease.
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http://dx.doi.org/10.1038/s41598-021-89213-4DOI Listing
May 2021

Anthropogenic underwater vibrations are sensed and stressful for the shore crab Carcinus maenas.

Environ Pollut 2021 Apr 16;285:117148. Epub 2021 Apr 16.

Biosciences, College of Life and Environmental Sciences, Hatherly Laboratories, University of Exeter, Stocker Road, Exeter, EX4 4PS, UK; Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile; Instituto Milenio de Oceanografía (IMO), Universidad de Concepción, Chile. Electronic address:

Acoustic pollution in aquatic environments has increased with adverse effects on many aquatic organisms. However, little work has been done considering the effects of the vibratory component of acoustic stimuli, which can be transmitted in the substrate and propagated into the aquatic medium. Benthic marine organisms, including many invertebrates, are capable of sensing seabed vibration, yet the responses they trigger on organism have received little attention. This study investigates the impact of underwater vibration on the physiology and behaviour of a ubiquitous inhabitant of coastal areas of the northern hemisphere, the shore crab Carcinus maenas. We developed a novel vibratory apparatus with geophones supported on a softly sprung frame to induce a seabed vibration of 20 Hz frequency, as observed during dredging, piling and other anthropogenic activities. The geophone internal mass caused the frame to vibrate in a controlled manner. Our results show that transition from ambient to anthropogenic vibrations induced an increase in activity and antennae beats in shore crabs, indicating perception of the vibratory stimulus and a higher stress level. There was also a trend on sex-specific responses to anthropogenic vibration, with males showing a higher activity level than females. However, no effect of anthropogenic vibrations was found upon oxygen consumption. These results show that anthropogenic underwater vibration induces behavioural responses in Carcinus maenas. This highlights the importance of evaluating man-made vibratory activities on coastal invertebrates and the necessity of evaluating anthropogenic effects on both sexes.
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http://dx.doi.org/10.1016/j.envpol.2021.117148DOI Listing
April 2021

Aerobic and anaerobic metabolic scaling in the burrowing freshwater crayfish Parastacus pugnax.

J Comp Physiol B 2021 May 4. Epub 2021 May 4.

Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile.

Metabolic scaling is a well-known biological pattern. Theoretical scaling exponents near 0.67 and 0.75 are the most widely accepted for aerobic metabolism, but little is known about the scaling of anaerobic metabolism. Furthermore, metabolic scaling has been mainly evaluated in organisms primarily relying on aerobic pathways. Here we evaluate both aerobic and anaerobic metabolic scaling in Parastacus pugnax, a burrowing freshwater crayfish endemic to Chile, which inhabits waters with low pO (~ 1 mg O L, measured in this study). We determined the metabolic rate, total oxidative capacity (Electron Transport System: ETS), critical oxygen tension (P) and muscular Lactate dehydrogenase (LHD) and Malate dehydrogenase (MDH) enzymatic activities (proxies of anaerobic metabolism) over a wide range of P. pugnax sizes (0.24-42.93 g wet mass). Aerobic metabolism scaled with crayfish size with an exponent of 0.78, remarkably similar to the 0.73 which scaled the ETS, the enzymatic complex behind respiration. Critical partial pressure of oxygen (P) was calculated as 15.6 ± 2.9 mmHg, showing that aerobic metabolism was efficiently maintained until ~ 10% air saturation. Below this threshold, P. pugnax switched to anaerobic metabolism, evidenced by a reduction in aerobic metabolism and ETS activity under chronic low oxygen conditions. None of the activities of MDH, LDH, their ratio (MDH/LDH), nor P scaled with crayfish size, indicating that these animals are equally adapted to hypoxic environments throughout their whole ontogeny. Given the particularities of its habitat, the information presented here is valuable for a proper management and successful conservation.
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http://dx.doi.org/10.1007/s00360-021-01374-wDOI Listing
May 2021

Age dependent physiological tolerances explain population dynamics and distribution in the intertidal zone: A study with porcelain crabs.

Mar Environ Res 2021 Apr 24;169:105343. Epub 2021 Apr 24.

Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile; Instituto Milenio de Oceanografía (IMO), Universidad de Concepción, PO Box 1313, Concepción, Chile. Electronic address:

Population dynamics and their response to environmental stressors have been widely studied in intertidal organisms. However, how these dynamics and responses change with animal age have been largely ignored to date. Traditionally, it is assumed that younger organisms are more sensitive than adults to environmental stressors; under this perspective it could be predicted that fully grown organisms should be able to occupy the harsh upper limit of their intertidal habitat. However, in some intertidal Porcelain crabs the opposite distribution has been observed. Using Petrolisthes laevigatus, we tested the physiological tolerance of crabs of different sizes (i.e. age) and evaluated how this trait shapes population dynamics (distribution and small-scale migrations under different weather conditions). We determined the abundance and size distribution of P. laevigatus at the middle and upper intertidal levels during sunny and rainy days, finding that abundances decreased drastically and size distribution shifted to smaller individuals on rainy days. In the laboratory, survival and behavioural responses of individuals in water at 5, 10, 15 and 33 PSU salinities were evaluated. Young crabs were found in higher proportion in the upper intertidal while fully grown crabs (i.e. adults) mainly occupied the middle intertidal zone. Young crabs had a higher osmoregulatory capacity than adults, as they were better at regulating passive water uptake when challenged with diluted seawater. This was also correlated with a lower lethal salinity LC in young crabs compared to adults. Behavioural trials showed that young crabs performed better escaping in both water and air, at intermediate and reduced salinities than adults. Therefore, weather influences small scale migrations from the upper to the lower intertidal zone, and this migration is also age-dependent, with younger crabs being more tolerant to low salinities and therefore allowing them to remain in the upper intertidal zone during raniny days.
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http://dx.doi.org/10.1016/j.marenvres.2021.105343DOI Listing
April 2021

Diel vertical migration into anoxic and high-pCO waters: acoustic and net-based krill observations in the Humboldt Current.

Sci Rep 2020 10 14;10(1):17181. Epub 2020 Oct 14.

Instituto Milenio de Oceanografía (IMO), Universidad de Concepción, Concepción, Chile.

A select group of marine organisms can enter the Oxygen Minimum Zones (OMZs) and even anoxic waters, while performing diel vertical migration (DVM). DVM of the euphausiid Euphausia eximia off northern Chile in the spring of 2015 was documented based on acoustic measurements using an echo sounder along with net samplings. Dissolved oxygen (DO) concentrations were obtained using a vertical profiler, and water samples were collected to obtain in situ nitrite (NO) concentrations as well as pH, total alkalinity (AT), and therefore carbon dioxide partial pressure (pCO) was estimated. Krill were found to migrate up to the surface (0-50 m) during the night and returned to ca. 200-300 m depth during the day, spending between 11 and 14 h at these layers. At the surface, DO and NO concentrations were 208 and 0.14 μM respectively, while pH was 8.04 and 405 μatm pCO. In contrast, at the deeper layers (200-300 m), DO and NO were < 3 and 6.3 μM respectively, with pH 7.53 and 1490 μatm pCO. The pH and high pCO values at depths represent the conditions predicted for open ocean waters in a worst-case global warming scenario by 2150. The acoustic scatter suggested that > 60% of the krill swarms enter the OMZ and anoxic waters during the daytime. These frequent migrations suggest that krill can tolerate such extreme conditions associated with anoxic and high-pCO waters. The inferences drawn from the observation of these migrations might have strong implications for the current oceanic carbon pump models, highlighting the need for understanding the molecular and physiological adaptations allowing these migrations.
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http://dx.doi.org/10.1038/s41598-020-73702-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7560619PMC
October 2020

Genomic basis of the loss of diadromy in Galaxias maculatus: Insights from reciprocal transplant experiments.

Mol Ecol 2020 12 4;29(24):4857-4870. Epub 2020 Nov 4.

Department of Biology, Dalhousie University, Halifax, NS, Canada.

Diadromy is known for having major effects on the distribution and richness of aquatic species, and so does its loss. The loss of diadromy has led to the diversification of many species, yet research focusing on understanding its molecular basis and consequences are limited. This is particularly true for amphidromous species despite being the most abundant group of diadromous species. Galaxias maculatus, an amphidromous species and one of the most widely distributed fishes in the Southern Hemisphere, exhibits many instances of nonmigratory or resident populations. The existence of naturally replicated resident populations in Patagonia can serve as an ideal system for the study of the mechanisms that lead to the loss of the diadromy and its ecological and evolutionary consequences. Here, we studied two adjacent river systems in which resident populations are genetically differentiated yet derived from the same diadromous population. By combining a reciprocal transplant experiment with genomic data, we showed that the two resident populations followed different evolutionary pathways by exhibiting a differential response in their capacity to survive in salt water. While one resident population was able to survive salt water, the other was not. Genomic analyses provided insights into the genes that distinguished (a) migratory from nonmigratory populations; (b) populations that can vs those that cannot survive a saltwater environment; and (c) between these resident populations. This study demonstrates that the loss of diadromy can be achieved by different pathways and that environmental (selection) and random (genetic drift) forces shape this dynamic evolutionary process.
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http://dx.doi.org/10.1111/mec.15686DOI Listing
December 2020

Water column circulation drives microplastic distribution in the Martínez-Baker channels; A large fjord ecosystem in Chilean Patagonia.

Mar Pollut Bull 2020 Nov 6;160:111591. Epub 2020 Sep 6.

Departamento de Oceanografía and Centro de Investigación Oceanográfica COPAS Sur-Austral (ANID), Universidad de Concepción, Concepción, Chile. Electronic address:

We investigated the distribution of microplastics in the water column along a large remote estuarine system located between the Northern and Southern Patagonian Ice Fields in Chilean Patagonia, and connected with the Pacific Ocean through the Gulf of Penas. Microplastic particles were found in all samples, with abundances ranging from 0.1 to 7 particles/m. Polymers identified were principally acrylics, PET, and cellophane. The average abundance of microplastics in surface waters was similar along the whole estuary (0.4 ± 0.3 particles/m) with acrylics and epoxy resins being more abundant near Caleta Tortel, the only small village in the area. The observed higher abundance of microplastics in the deeper waters towards the Gulf of Penas points to intrusions of subsurface waters transporting plastic particles from the ocean into the channel system. This underlines the potential of ocean currents in transporting plastic pollution into pristine fjords and channels in Chilean Patagonia.
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http://dx.doi.org/10.1016/j.marpolbul.2020.111591DOI Listing
November 2020

Adsorption of polyethylene microbeads and physiological effects on hydroponic maize.

Sci Total Environ 2020 Nov 15;741:140216. Epub 2020 Jun 15.

Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, 4070386 Concepción, Chile; ARAID - Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda. Montañana 930, 50059 Zaragoza, Spain. Electronic address:

About 90% of the plastic garbage remains in terrestrial ecosystems, and increasing evidence highlights the exposure of crops to plastic particles. However, the potential bioaccumulation of microplastics by plants and their effects on plants' physiology remains unexplored. Here, we evaluated the adsorption, potential uptake, and physiological effects of polyethylene (PE) microbeads in an experimental hydroponic culture of maize. Using isotope analysis, taking advantage of the different carbon isotope composition (δC) of fossil-derived PE and C plants (e.g., maize), we estimated that about 30% of the carbon in the rhizosphere of microplastic-exposed plants was derived from PE. Still, we did not find evidence of PE translocation to the shoots. Plastic bioaccumulation in the rhizosphere caused a significant decline in transpiration, nitrogen content, and growth. Our results indicate that plastic particles may accumulate in the rhizosphere, impairing water and nutrient uptake, and eventually reaching root eaters. Due to the implications for food production and livestock feeding, our findings encourage further research on the mechanism leading to the bioaccumulation of microplastics on the surface of belowground tissues.
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http://dx.doi.org/10.1016/j.scitotenv.2020.140216DOI Listing
November 2020

Monitoring the occurrence of microplastic ingestion in Otariids along the Peruvian and Chilean coasts.

Mar Pollut Bull 2020 Apr 29;153:110966. Epub 2020 Feb 29.

Departamento de Ciencias de la Vida, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile; Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile; GEMA Center for Genomics, Ecology & Environment, Universidad Mayor, Camino La Pirámide 5750, Huechuraba, Santiago, Chile. Electronic address:

Repeated reports of microplastic pollution in the marine pinniped diet have emerged in the last years. However, only few studies address the drivers of microplastics presence and the potential implications for monitoring microplastic pollution in the ocean. This study monitored their in the scats (N = 205) of four pinniped species/subspecies at five different locations in the southern Pacific Ocean (Peru and Chile). Samples from all rookeries contained microplastics, and overall, 68% of the examined scats contained fragments/fibers, mostly blue colored. We confirmed that 81.5% of the fragments/fibers were anthropogenic in origin , but only 30% were polymers. Scats from Juan Fernández Archipelago presented higher microplastic concentrations than continental rookeries. Also, the common diet in each location may influence the levels found in the samples. This study presents a useful non-invasive technique to track plastic pollution in top predator diets as bioindicators for future surveillance/management plans applied to different location.
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http://dx.doi.org/10.1016/j.marpolbul.2020.110966DOI Listing
April 2020

High Levels of Glycosaminoglycans in the Urines of Children with Attention-Deficit/Hyperactivity Disorder (ADHD).

J Mol Neurosci 2020 Jul 4;70(7):1018-1025. Epub 2020 Mar 4.

Department of Pediatrics, Josa András County Hospital, Nyíregyháza, Hungary.

Attention-deficit/hyperactivity disorder (ADHD) is a common neurobehavioral/neurodevelopmental disorder. Some early studies indicated that increased intake of added sugars might have a role in ADHD. In the present study, we tested this possibility by evaluating the urinary excretion of oligosaccharides and glycosaminoglycans (GAGs) in ADHD and control subjects. Forty ADHD subjects matched with 34 controls were enrolled in the study. The subjects underwent a standardized dietary regimen. The urine levels of oligosaccharides and GAGs were quantified biochemically, and their covariance and association were evaluated statistically. Fructose (21/40, 52.5%), maltose (26/40, 65%), galactose (30/40, 75%), and lactose (38/40, 95%) excretions were frequently found in the urine of ADHD subjects (p < 0.05), an excretion which does not occur normally. Furthermore, these subjects showed a pathologic tGAG (glycosaminoglycan) excretion (40/40, 100%). The present study supports the thesis that carbohydrate metabolism differs in ADHD subjects compared with control subjects.
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http://dx.doi.org/10.1007/s12031-020-01496-wDOI Listing
July 2020

Oxidative Stress in Autism Spectrum Disorder.

Mol Neurobiol 2020 May 5;57(5):2314-2332. Epub 2020 Feb 5.

Department of Neurological and Movement Sciences, University of Verona, Verona, Italy.

According to the United States Centers for Disease Control and Prevention (CDC), as of July 11, 2016, the reported average incidence of children diagnosed with an autism spectrum disorder (ASD) was 1 in 68 (1.46%) among 8-year-old children born in 2004 and living within the 11 monitoring sites' surveillance areas in the United States of America (USA) in 2012. ASD is a multifaceted neurodevelopmental disorder that is also considered a hidden disability, as, for the most part; there are no apparent morphological differences between children with ASD and typically developing children. ASD is diagnosed based upon a triad of features including impairment in socialization, impairment in language, and repetitive and stereotypic behaviors. The increasing incidence of ASD in the pediatric population and the lack of successful curative therapies make ASD one of the most challenging disorders for medicine. ASD neurobiology is thought to be associated with oxidative stress, as shown by increased levels of reactive oxygen species and increased lipid peroxidation, as well as an increase in other indicators of oxidative stress. Children with ASD diagnosis are considered more vulnerable to oxidative stress because of their imbalance in intracellular and extracellular glutathione levels and decreased glutathione reserve capacity. Several studies have suggested that the redox imbalance and oxidative stress are integral parts of ASD pathophysiology. As such, early assessment and treatment of antioxidant status may result in a better prognosis as it could decrease the oxidative stress in the brain before it can induce more irreversible brain damage. In this review, many aspects of the role of oxidative stress in ASD are discussed, taking into account that the process of oxidative stress may be a target for therapeutic interventions.
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http://dx.doi.org/10.1007/s12035-019-01742-2DOI Listing
May 2020

Marine invertebrate larvae love plastics: Habitat selection and settlement on artificial substrates.

Environ Pollut 2020 Feb 6;257:113571. Epub 2019 Nov 6.

Departamento de zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile.

Global urbanization and plastic pollution has increased the availability and variety of substrates for sessile organisms, and are intensively used by invasive species for settlement. Despite extensive literature describing the strong association between artificial structures and invasive species, little effort has been directed towards identifying the larval traits that favor this selection. Larval selection and settlement are crucial as larvae actively search and interpret environmental cues to identify suitable habitats to settle. The aim of this research was to investigate if invertebrate larvae have a preference for a particular anthropogenic substrate, and how pre-settlement behaviors vary when encountering different substrates. We used two invasive bryozoan species, Bugula flabellata and Bugula neritina, which are commonly found in urbanized areas around the world. Energy expenditure during planktonic and benthonic stages, pre-settlement swimming/exploring behaviors, settlement and larval selectivity were quantified under laboratory conditions on different substrates (concrete, wood, polystyrene, polyvinyl chloride, polyethylene terephthalate and polycarbonate). The energy expenditure measured was higher in planktonic larvae than in early settled larvae. Larvae of both species swam less and explored more when exposed to plastic surfaces, suggesting a preference for this substrate and resulting in lower energy expenditures associated with searching for habitat. Larvae actively chose to settle on plastics rather than on wood or concrete substrates. The results suggest that for Bugula larvae, the likelihood of colonizing plastic surfaces is higher than other materials commonly found in urbanized coastal areas. The more quickly they adhere to artificial substrates the lower the energy expenditure, contributing to higher fitness in these individuals. The strong preference of invertebrate larvae for plastics can potentially extend the distribution range of many invasive marine species as they are able to travel long distances attached to floating debris. This phenomenon will likely exacerbate the introduction of exotic species into novel habitats.
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http://dx.doi.org/10.1016/j.envpol.2019.113571DOI Listing
February 2020

Decreased Metabolic Rate in the Mole Crabs, Emerita analoga, Infected with the Acanthocephalan Profilicollis altmani.

J Parasitol 2019 02;105(1):19-24

3   Instituto de Acuicultura, Universidad Austral de Chile, P.O. Box 1327, Puerto Montt, Chile.

The relationship between a parasite and its host will have an energy cost for the host at some point; however, this basic hypothesis has seldom been evaluated. Using Emerita analoga as a model species, we investigated the aerobic metabolism, ammonia excretion rate, and locomotor performance patterns of crabs both uninfected and infected with the acanthocephalan Profilicollis altmani. Our results show that infected Emerita had a lower metabolic rate compared to uninfected ones. Whether or not this decrease is a result of the pathology of the parasite infection or due to manipulation of the host by the parasite is still unknown. We discuss the importance of using anaerobic and aerobic metabolism and more-complex scenarios in order to understand the effects on host fitness and not only on the immediate response of the host.
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February 2019

A systematic review and meta-analysis of metal concentrations in canned tuna fish in Iran and human health risk assessment.

Food Chem Toxicol 2018 Aug 18;118:753-765. Epub 2018 Jun 18.

Council for Nutritional and Environmental Medicine, Mo i Rana, Norway. Electronic address:

Human consumption of fish protein, including canned tuna fish, is increasing steadily worldwide. However, there are some concerns about the potential exposure to elevated concentrations of metals in canned tuna fish. Several studies have been conducted in Iran regarding the concentration of metals in seafood, including copper (Cu), selenium (Se), iron (Fe), zinc (Zn), mercury (Hg), lead (Pb), chromium (Cr), arsenic (As), nickel (Ni), tin (Sn), and cadmium (Cd) in canned tuna fish. The main aim of this study was to gather data from existing papers and to perform a meta-analysis of the pooled concentrations of metals to evaluate their non-carcinogenic and carcinogenic risks in children and adults consumers. Search was conducted retrieving data from the international biomedical databases with highly public access and consultation, e.g., Web of Science, PubMed, Science Direct, and Scopus, and national database (SID and Irandoc) between 1983 and November of 2017. Data from 23 articles and 1295 samples were assessed and extracted. The ranking order of metals based on mean concentrations (μg/g wet weight) were Fe (13.17) > Zn (9.31) > Se (2.23) > Al (1.8) > Cr (1.63) > Cu (1.52) > As (0.38) > Ni (0.33) > Pb (0.24) > Cd (0.14) > Hg (0.11) > Sn (0.1). Except for Cd and Se, concentrations of other metals in the canned tuna fish were lower than the limits recommended by the United States Environmental Protection Agency (USEPA), World Health Organization (WHO), Food and Agriculture Organization (FAO) and Iran National Standards Organization (INSO). The minimum and maximum target hazard quotient (THQ) for adults were 5.55E-5 for Al and 2.23E-08 for Cr. For children, they were 7.23E-05 for Al and 2.91E-08 for Cr. THQ, and total target hazard quotient (TTHQ) were ≤1.0 for adult and children consumers. The Incremental Lifetime Cancer Risk (ILCR) of As was 3.21E-5 in adults and 4.18E-5 in children. Adults and children that consume canned tuna fish in Iran are not at non-carcinogenic risk but have a carcinogenic risk due to As.
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http://dx.doi.org/10.1016/j.fct.2018.06.023DOI Listing
August 2018

Cerebral hypoperfusion in autism spectrum disorder.

Acta Neurobiol Exp (Wars) 2018 ;78(1):21-29

Faculty of Public Health, Inland Norway University of Applied Sciences, Elverum, Norway; Department of Research, Innlandet Hospital Trust, Brumunddal, Norway.

Cerebral hypoperfusion, or insufficient blood flow in the brain, occurs in many areas of the brain in patients diagnosed with autism spectrum disorder (ASD). Hypoperfusion was demonstrated in the brains of individuals with ASD when compared to normal healthy control brains either using positron emission tomography (PET) or single‑photon emission computed tomography (SPECT). The affected areas include, but are not limited to the: prefrontal, frontal, temporal, occipital, and parietal cortices; thalami; basal ganglia; cingulate cortex; caudate nucleus; the limbic system including the hippocampal area; putamen; substantia nigra; cerebellum; and associative cortices. Moreover, correlations between symptom scores and hypoperfusion in the brains of individuals diagnosed with an ASD were found indicating that the greater the autism symptom pathology, the more significant the cerebral hypoperfusion or vascular pathology in the brain. Evidence suggests that brain inflammation and vascular inflammation may explain a part of the hypoperfusion. There is also evidence of a lack of normal compensatory increase in blood flow when the subjects are challenged with a task. Some studies propose treatments that can address the hypoperfusion found among individuals diagnosed with an ASD, bringing symptom relief to some extent. This review will explore the evidence that indicates cerebral hypoperfusion in ASD, as well as the possible etiological aspects, complications, and treatments.
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September 2018

Low prevalence of microplastic contamination in planktivorous fish species from the southeast Pacific Ocean.

Mar Pollut Bull 2018 Feb 21;127:211-216. Epub 2017 Dec 21.

Facultad Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile; Millennium Nucleus Ecology and Sustainable Management of Oceanic Island (ESMOI), Coquimbo, Chile; Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Coquimbo, Chile. Electronic address:

The gut contents of 292 planktivorous fish, from four families (Atherinopsidae, Clupeidae, Engraulidae and Scombridae) and seven species, captured along the coast of the southeast Pacific, were examined for microplastic contamination. Only a small fraction of all studied fish (2.1%; 6 individuals) contained microplastic particles in their digestive tract. Microplastics found were degraded hard fragments and threads, ranging from 1.1 to 4.9 (3.8±SD 2.4) mm in length, and of various colours, which suggests that the planktivorous fish species examined herein did not capture microplastics on the basis of their colour. The low prevalence of microplastic contamination in planktivorous fishes found in this study suggests that the risk of accidental ingestion by these species might be limited in the coastal upwelled waters of the southeast Pacific, perhaps due to small human population and highly dynamic oceanographic processes.
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http://dx.doi.org/10.1016/j.marpolbul.2017.12.016DOI Listing
February 2018

Relationship between absolute and relative ratios of glutamate, glutamine and GABA and severity of autism spectrum disorder.

Metab Brain Dis 2018 06 3;33(3):843-854. Epub 2018 Feb 3.

Autism Research and Treatment Center, Riyadh, Saudi Arabia.

Autism spectrum disorder (ASD) is a neurodevelopmental pathology characterized by an impairment in social interaction, communication difficulties, and repetitive behaviors. Glutamate signaling abnormalities are thought to be considered as major etiological mechanisms leading to ASD. The search for amino-acidic catabolytes related to glutamate in patients with different levels of ASD might help current research to clarify the mechanisms underlying glutamate signaling and its disorders, particularly in relation to ASD. In the present study, plasma levels of the amino acids and their derivatives glutamate, glutamine, and γ-aminobutyric acid (GABA), associated with their relative ratios, were evaluated using an enzyme-linked immunosorbent assay (ELISA) technique in 40 male children with ASD and in 38 age- and gender-matched neurotypical health controls. The Social Responsiveness Scale (SRS) was used to evaluate social cognition, and the Childhood Autism Rating Scale (CARS) was used to assess subjects' behaviors. Children with ASD exhibited a significant elevation of plasma GABA and glutamate/glutamine ratio, as well as significantly lower levels of plasma glutamine and glutamate/GABA ratios compared to controls. No significant correlation was found between glutamate levels and the severity of autism, measured by CARS and SRS. In receiver operating characteristic (ROC) curve analysis, the area under the curve for GABA compared to other parameters was close to one, indicating its potential use as a biomarker. Glutamine appeared as the best predictive prognostic markers in the present study. The results of the present study indicate a disturbed balance between GABAergic and glutamatergic neurotransmission in ASD. The study also indicates that an increased plasma level of GABA can be potentially used as an early diagnostic biomarker for ASD.
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http://dx.doi.org/10.1007/s11011-018-0186-6DOI Listing
June 2018

Hydroclimatic conditions trigger record harmful algal bloom in western Patagonia (summer 2016).

Sci Rep 2018 01 22;8(1):1330. Epub 2018 Jan 22.

Instituto de Acuicultura and Centro de Investigación Dinámica de Ecosistemas Marinos de Altas Latitudes - IDEAL, Universidad Austral de Chile, Los Pinos s/n, Puerto Montt, Chile.

A harmful algal bloom (HAB) of the raphidophyta alga Pseudochattonella cf. verruculosa during the 2016 austral summer (February-March) killed nearly 12% of the Chilean salmon production, causing the worst mass mortality of fish and shellfish ever recorded in the coastal waters of western Patagonia. The HAB coincided with a strong El Niño event and the positive phase of the Southern Annular Mode that altered the atmospheric circulation in southern South America and the adjacent Pacific Ocean. This led to very dry conditions and higher than normal solar radiation reaching the surface. Using time series of atmospheric, hydrologic and oceanographic data we show here that an increase in surface water temperature and reduced freshwater input resulted in a weakening of the vertical stratification in the fjords and sounds of this region. This allowed the advection of more saline and nutrient-rich waters, ultimately resulting in an active harmful algal bloom in coastal southern Chile.
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http://dx.doi.org/10.1038/s41598-018-19461-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5777999PMC
January 2018

Metals and Parkinson's Disease: Mechanisms and Biochemical Processes.

Curr Med Chem 2018 ;25(19):2198-2214

Department of Environmental and Integrative Medicine, Medical Center, Konstanz, Germany.

Genetic background accounts for only 5 to 10% of the reported cases of Parkinson's disease (PD), while the remaining cases are of unknown etiology. It is believed that environmental factors may be involved in the causality of a large proportion of PD cases. Several PD genes are activated by xenobiotic exposure, and a link between pesticide exposure and PD has been demonstrated. Many epidemiological studies have shown an association between PD and exposure to metals such as mercury, lead, manganese, copper, iron, aluminum, bismuth, thallium, and zinc. This review explores the biological effects, the pathogenetic processes, genetic susceptibilities to metals as well as examining future strategies for PD treatment, such as chelation therapy.
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http://dx.doi.org/10.2174/0929867325666171129124616DOI Listing
August 2018

Fluctuating seawater pH/CO regimes are more energetically expensive than static pH/CO levels in the mussel .

Proc Biol Sci 2017 Oct;284(1865)

Department of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter EX4 4QD, UK

Ocean acidification (OA) studies typically use stable open-ocean pH or CO values. However, species living within dynamic coastal environments can naturally experience wide fluctuations in abiotic factors, suggesting their responses to stable pH conditions may not be reflective of either present or near-future conditions. Here we investigate the physiological responses of the mussel to variable seawater pH conditions over short- (6 h) and medium-term (2 weeks) exposures under both current and near-future OA scenarios. Mussel haemolymph pH closely mirrored that of seawater pH over short-term changes of 1 pH unit with acidosis or recovery accordingly, highlighting a limited capacity for acid-base regulation. After 2 weeks, mussels under variable pH conditions had significantly higher metabolic rates, antioxidant enzyme activities and lipid peroxidation than those exposed to static pH under both current and near-future OA scenarios. Static near-future pH conditions induced significant acid-base disturbances and lipid peroxidation compared with the static present-day conditions but did not affect the metabolic rate. These results clearly demonstrate that living in naturally variable environments is energetically more expensive than living in static seawater conditions, which has consequences for how we extrapolate future OA responses in coastal species.
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http://dx.doi.org/10.1098/rspb.2017.1642DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5666100PMC
October 2017

Plasma alpha-L-fucosidase activity in chronic inflammation and autoimmune disorders in a pediatric cohort of hospitalized patients.

Immunol Res 2017 10;65(5):1025-1030

Department of Pediatrics and Pediatric Health Care Center, Faculty of Medicine, University of Szeged, Szeged, Hungary.

Human α-fucosidase (EC 3.2.1.51) is an enzyme (hydrolase) of particular biological and medical interest, as the inherited deficiency in its activity leads to fucosidosis, a pathology belonging to severe glycoprotein lysosomal storage disorders. Although its importance has increased in latest years, data about its plasma level in children with inflammatory disorders are still lacking. In the present study, plasma activity of α-L-fucosidase-1 (FUCA-1) and its potential association with chronic inflammatory pathologies was evaluated in hospitalized individuals, both pediatric and adult ones. A number of 201 Hungarian hospitalized patients, 144 children (1-13 years) and 57 adults (31-88 years), were enrolled in the study and underwent plasma assay of FUCA-1 activity, following the normal routine analytical run in the hospital service. Regression and Pearson tests were evaluated to investigate the relationship between FUCA-1 plasma levels and inflammatory disorders diagnosed with subjects recruited in the study. No correlation of FUCA-1 activity was observed in the pediatric patients with immune (p = 0.9677) or metabolic (p = 0.6974) disorders, but a correlation was reported when comparing clusters of chronic inflammatory and autoimmune disease vs. controls (p < 0.05). Furthermore, a relationship was found between FUCA-1 activity in plasma and inflammatory disorders and autoimmunity both in adults and in the pediatric cohort of patients (Pearson test, p = 0.000148). Alterations in plasma levels of FUCA-1 were significantly associated with chronic inflammatory and autoimmune disorders, both in children and adults. The result of the present study should encourage further research on FUCA-1 as a marker of chronic inflammation and autoimmunity.
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http://dx.doi.org/10.1007/s12026-017-8943-xDOI Listing
October 2017

Impacts of ocean acidification on sperm develop with exposure time for a polychaete with long lived sperm.

Mar Environ Res 2017 Aug 16;129:268-276. Epub 2017 Jun 16.

College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK. Electronic address:

The majority of marine invertebrate species release eggs and sperm into seawater for external fertilisation. Seawater conditions are currently changing at an unprecedented rate as a consequence of ocean acidification (OA). Sperm are thought to be particularly vulnerable to these changes and may be exposed to external environmental conditions for variable periods of time between spawning and fertilisation. Here, we undertook a mechanistic investigation of sperm swimming performance in the coastal polychaete Arenicola marina during an extended exposure to OA conditions (pH 7.77, 1000 μatm pCO). We found that key fitness-related aspects of sperm functioning declined faster under OA conditions i.e. impacts became apparent with exposure time. Sperm swimming speed (VCL), the number of motile sperm and sperm path linearity all dropped significantly after 4 h under OA conditions whilst remaining constant under ambient conditions at this time point. Our results highlight the importance of sperm exposure duration in ocean acidification experiments and may help towards explaining species specific differences in response.
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http://dx.doi.org/10.1016/j.marenvres.2017.06.011DOI Listing
August 2017

Ecophysiological adaptations to variable salinity environments in the crab Hemigrapsus crenulatus from the Southeastern Pacific coast: Sodium regulation, respiration and excretion.

Comp Biochem Physiol A Mol Integr Physiol 2017 08 27;210:35-43. Epub 2017 May 27.

Departamento de Zoología, Facultad de Ciencias Naturales y Oceanografía, Universidad de Concepción, Casilla 160-C, Concepción, Chile. Electronic address:

The estuarine crab Hemigrapsus crenulatus is a key benthic species of estuarine and intertidal ecosystems of the South Pacific, habitats that experience wide fluctuations in salinity. The physiological strategies that allow this crab to thrive under variable salinities, and how they change during the benthic stages of their life cycle, were evaluated under laboratory conditions. Oxygen consumption, ammonia excretion and the regulatory capacity of Na through the normal range of environmental salinities (i.e. 5, 10, 15, 20, 25, 30) were evaluated in three size classes, ranging from juveniles to adults. In all sizes, the oxygen consumption, ammonia excretion and regulatory capacity of Na decreased as salinity increased, with the highest values at 5 and the lowest values at 30 salinity. Bigger crabs showed a higher capacity to regulate Na, as well as higher respiration and excretion rates compared to smaller crabs, suggesting that they are better equipped to exploit areas of the estuary with low salinity. Regardless of its size, H. crenulatus is a strong hyper regulator in diluted media (i.e. 5-20) while a conformer at salinities higher than 20. The regulatory capacity of Na was positively related with oxygen consumption and ammonia excretion rates. These relationships between sodium regulation, respiration and excretion are interpreted as adaptive physiological mechanisms that allow H. crenulatus to maintain the osmotic and bioenergetic balance over a wide range of environmental salinities.
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http://dx.doi.org/10.1016/j.cbpa.2017.05.010DOI Listing
August 2017

Effects of arsenic toxicity beyond epigenetic modifications.

Environ Geochem Health 2018 Jun 8;40(3):955-965. Epub 2017 May 8.

Department of Pharmacy, Stamford University Bangladesh, Dhaka, Bangladesh.

Worldwide chronic arsenic (As) poisoning by arsenic-contaminated groundwater is one of the most threatening public health problems. Chronic inorganic As (inAs) exposure has been associated with various forms of cancers and numerous other pathological effects in humans, collectively known as arsenicosis. Over the past decade, evidence indicated that As-induced epigenetic modifications have a role in the adverse effects on human health. The main objective of this article is to review the evidence on epigenetic modifications induced by arsenicals. The epigenetic components play a crucial role in the regulation of gene expression, at both transcriptional and posttranscriptional levels. We synthesized the large body of existing research on arsenic exposure and epigenetic mechanisms of health outcomes with an emphasis on recent publications. Changes in patterns of DNA methylation, histone posttranslational modifications, and microRNAs have been repeatedly observed after inAs exposure in laboratory studies and in studies of human populations. Such alterations have the potential to disturb cellular homeostasis, resulting in the modulation of key pathways in the As-induced carcinogenesis. The present article reviews recent data on As-induced epigenetic effects and concludes that it is time for heightened awareness of pathogenic arsenic exposure, particularly for pregnant women and children, given the potential for a long-lasting disturbed cellular homeostasis.
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http://dx.doi.org/10.1007/s10653-017-9967-9DOI Listing
June 2018

Does sex really matter? Explaining intraspecies variation in ocean acidification responses.

Biol Lett 2017 02;13(2)

Departamento de Zoología, Universidad de Concepción, Concepción, Chile.

Ocean acidification (OA) poses a major threat to marine ecosystems globally, having significant ecological and economic importance. The number and complexity of experiments examining the effects of OA has substantially increased over the past decade, in an attempt to address multi-stressor interactions and long-term responses in an increasing range of aquatic organisms. However, differences in the response of males and females to elevated pCO have been investigated in fewer than 4% of studies to date, often being precluded by the difficulty of determining sex non-destructively, particularly in early life stages. Here we highlight that sex can significantly impact organism responses to OA, differentially affecting physiology, reproduction, biochemistry and ultimately survival. What is more, these impacts do not always conform to ecological theory based on differential resource allocation towards reproduction, which would predict females to be more sensitive to OA owing to the higher production cost of eggs compared with sperm. Therefore, non-sex-specific studies may overlook subtle but ecologically significant differences in the responses of males and females to OA, with consequences for forecasting the fate of natural populations in a near-future ocean.
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http://dx.doi.org/10.1098/rsbl.2016.0761DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5326506PMC
February 2017

Immune dysfunction and neuroinflammation in autism spectrum disorder.

Acta Neurobiol Exp (Wars) 2016 ;76(4):257-268

Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile.

Autism spectrum disorder (ASD) is a complex heterogeneous neurodevelopmental disorder with a complex pathogenesis. Many studies over the last four decades have recognized altered immune responses among individuals diagnosed with ASD. The purpose of this critical and comprehensive review is to examine the hypothesis that immune dysfunction is present more frequently, and it is related to ASD in humans. It was found that that often individuals diagnosed with ASD have alterations in immune cells such as T cells, B cells, monocytes, natural killer cells, and dendritic cells. Also, many individuals diagnosed with ASD have alterations in immunoglobulins and increased autoantibodies. Finally, an important portion of individuals diagnosed with ASD has elevated peripheral cytokines and chemokines and associated neuroinflammation. In conclusion, immune dysregulation and inflammation are important components of ASD diagnosis and are key components of the diagnosis and treatment of ASD.
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http://dx.doi.org/10.21307/ane-2017-025DOI Listing
February 2017

May traffic air pollution be involved in autism spectrum disorder?

Environ Res 2017 04 27;154:57-59. Epub 2016 Dec 27.

Department of Neurological and Movement Sciences, University of Verona, Strada Le Grazie 9, 37134 Verona, Italy; Council for Nutritional and Environmental Medicine, Mo i Rana, Norway; Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile.

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http://dx.doi.org/10.1016/j.envres.2016.12.023DOI Listing
April 2017

Randomized controlled trial of vitamin D supplementation in children with autism spectrum disorder.

J Child Psychol Psychiatry 2018 Jan 21;59(1):20-29. Epub 2016 Nov 21.

Department of Pharmaceutics and Industrial Pharmacy, Alazhar University, Assiut, Egypt.

Background: Autism spectrum disorder (ASD) is a frequent developmental disorder characterized by pervasive deficits in social interaction, impairment in verbal and nonverbal communication, and stereotyped patterns of interests and activities. It has been previously reported that there is vitamin D deficiency in autistic children; however, there is a lack of randomized controlled trials of vitamin D supplementation in ASD children.

Methods: This study is a double-blinded, randomized clinical trial (RCT) that was conducted on 109 children with ASD (85 boys and 24 girls; aged 3-10 years). The aim of this study was to assess the effects of vitamin D supplementation on the core symptoms of autism in children. ASD patients were randomized to receive vitamin D3 or placebo for 4 months. The serum levels of 25-hydroxycholecalciferol (25 (OH)D) were measured at the beginning and at the end of the study. The autism severity and social maturity of the children were assessed by the Childhood Autism Rating Scale (CARS), Aberrant Behavior Checklist (ABC), Social Responsiveness Scale (SRS), and the Autism Treatment Evaluation Checklist (ATEC).

Trial Registration Number: UMIN-CTR Study Design: trial number: UMIN000020281.

Results: Supplementation of vitamin D was well tolerated by the ASD children. The daily doses used in the therapy group was 300 IU vitamin D3/kg/day, not to exceed 5,000 IU/day. The autism symptoms of the children improved significantly, following 4-month vitamin D3 supplementation, but not in the placebo group. This study demonstrates the efficacy and tolerability of high doses of vitamin D3 in children with ASD.

Conclusions: This study is the first double-blinded RCT proving the efficacy of vitamin D3 in ASD patients. Depending on the parameters measured in the study, oral vitamin D supplementation may safely improve signs and symptoms of ASD and could be recommended for children with ASD. At this stage, this study is a single RCT with a small number of patients, and a great deal of additional wide-scale studies are needed to critically validate the efficacy of vitamin D in ASD.
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http://dx.doi.org/10.1111/jcpp.12652DOI Listing
January 2018

Lessons from two high CO worlds - future oceans and intensive aquaculture.

Glob Chang Biol 2017 06 20;23(6):2141-2148. Epub 2016 Oct 20.

Biosciences, University of Exeter, Geoffrey Pope BuildingStocker Road, EX4 4QD, Exeter, UK.

Exponentially rising CO (currently ~400 μatm) is driving climate change and causing acidification of both marine and freshwater environments. Physiologists have long known that CO directly affects acid-base and ion regulation, respiratory function and aerobic performance in aquatic animals. More recently, many studies have demonstrated that elevated CO projected for end of this century (e.g. 800-1000 μatm) can also impact physiology, and have substantial effects on behaviours linked to sensory stimuli (smell, hearing and vision) both having negative implications for fitness and survival. In contrast, the aquaculture industry was farming aquatic animals at CO levels that far exceed end-of-century climate change projections (sometimes >10 000 μatm) long before the term 'ocean acidification' was coined, with limited detrimental effects reported. It is therefore vital to understand the reasons behind this apparent discrepancy. Potential explanations include 1) the use of 'control' CO levels in aquaculture studies that go beyond 2100 projections in an ocean acidification context; 2) the relatively benign environment in aquaculture (abundant food, disease protection, absence of predators) compared to the wild; 3) aquaculture species having been chosen due to their natural tolerance to the intensive conditions, including CO levels; or 4) the breeding of species within intensive aquaculture having further selected traits that confer tolerance to elevated CO . We highlight this issue and outline the insights that climate change and aquaculture science can offer for both marine and freshwater settings. Integrating these two fields will stimulate discussion on the direction of future cross-disciplinary research. In doing so, this article aimed to optimize future research efforts and elucidate effective mitigation strategies for managing the negative impacts of elevated CO on future aquatic ecosystems and the sustainability of fish and shellfish aquaculture.
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http://dx.doi.org/10.1111/gcb.13515DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5434897PMC
June 2017

Temporal variation on environmental variables and pollution indicators in marine sediments under sea Salmon farming cages in protected and exposed zones in the Chilean inland Southern Sea.

Sci Total Environ 2016 Dec 3;573:841-853. Epub 2016 Sep 3.

Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile. Electronic address:

The impacts of any activity on marine ecosystems will depend on the characteristics of the receptor medium and its resilience to external pressures. Salmon farming industry develops along a constant gradient of hydrodynamic conditions in the south of Chile. However, the influence of the hydrodynamic characteristics (weak or strong) on the impacts of intensive salmon farming is still poorly understood. This one year study evaluates the impacts of salmon farming on the marine sediments of both protected and exposed marine zones differing in their hydrodynamic characteristics. Six physico-chemical, five biological variables and seven indexes of marine sediments status were evaluated under the salmon farming cages and control sites. Our results identified a few key variables and indexes necessary to accurately evaluate the salmon farming impacts on both protected and exposed zones. Interestingly, the ranking of importance of the variables and the temporality of the observed changes, varied depending on the hydrodynamic characteristics. Biological variables (nematodes abundance) and environmental indexes (Simpson's dominance, Shannon's diversity and Pielou evenness) are the first to reflect detrimental impacts under the salmon farming cages. Then the physico-chemical variables such as redox, sulphurs and phosphorus in both zones also show detrimental impacts. Based on the present results we propose that the hydrodynamic regime is an important driver of the magnitude and temporality of the effects of salmon farming on marine sediments. The variables and indexes that best reflect the effects of salmon farming, in both protected and exposed zones, are also described.
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http://dx.doi.org/10.1016/j.scitotenv.2016.08.166DOI Listing
December 2016