Maikel Rosabal

• PhD
• University of Quebec in Montreal

Methylmercury (MeHg) readily bioaccumulates and biomagnifies in aquatic food webs leading to elevated concentrations in fish and may thus induce toxicity. Oxidative stress is a suggested effect of MeHg bioaccumulation in fish. However, studies on how MeHg triggers oxidative stress in wild fish are scarce. The purpose of this study was to link the s...

Methylmercury (MeHg) readily bioaccumulates and biomagnifies in aquatic food webs leading to elevated concentrations in fish and may thus induce toxicity. Oxidative stress is a suggested effect of MeHg bioaccumulation in fish. However, studies on how MeHg triggers oxidative stress in wild fish are scarce. The purpose of this study was to link the s...

Depuis 1984, l’affinage de concentrés complexes à la fonderie Horne, située à Rouyn-Noranda au Québec, justifie une vigilance accrue relative à la présence de contaminants métalliques potentiellement émis dans l’atmosphère de la région. La fonderie est d’ailleurs reconnue pour ses émissions d’arsenic (As), cadmium (Cd), plomb (Pb), cuivre (Cu), etc...

La demande et l’émission dans l’environnement de métaux du groupe du platine, notamment le platine (Pt) et le palladium (Pd), ne cessent d’augmenter en raison de leur utilisation croissante dans de nombreuses industries de pointe (haute technologie, automobile, médecine). Pour répondre à cette préoccupation environnementale, des informations concer...

Since the growing demand of platinum group elements (PGE) in cutting-edge industries (high- tech, automobile, medical), the concentration of these emerging contaminants, which includes the platinum (Pt) and the palladium (Pd), has been increasing in the environment. To address this concern regarding the growing PGE contamination, information about...

Abandoned and flooded ore mines are examples of hostile environments (cold, dark, oligotrophic, trace metal) with a potential vast diversity of microbial communities rarely characterized. This study aimed to understand the effects of depth, the source of water (surface or groundwater), and abiotic factors on the communities present in the old Forsy...

Hunting has multiple consequences for wildlife, and it can be an important source of environmental pollution. Most big game hunters use lead (Pb) ammunition that shed metal fragments in the tissues of harvested animals. These Pb fragments become available to scavengers when hunters discard contaminated slaughter remains in the environment. This exp...

The subcellular partitioning approach provides useful information on the location of metals within cells and is often used on organisms with high levels of bioaccumulation to establish relationships between the internal concentration and the toxicity potential of metals. Relatively little is known about the subcellular partitioning of metals in wil...

Copper (Cu) is a redox-active transition element critical to various metabolic processes. These functions are accomplished in tandem with Cu binding ligands, mainly proteins. The main goal of this work was to understand the mechanisms that govern the intracellular fate of Cu in the freshwater green alga, Chlamydomonas reinhardtii, and more specific...

Uptake of the neurotoxicant monomethylmercury (MeHg) from fish and marine mammals continues to present a public health concern in Canada and elsewhere. However, fish and marine mammals are key diet items contributing to food security for some Indigenous populations in Canada. Mercury (Hg) exposure is estimated assuming that 100% of Hg is methylated...

Fish consumption is the main exposure pathway of the neurotoxicant methylmercury (MeHg) in humans. The risk associated with exposure to MeHg may be modified by its interactions with selenium (Se) and arsenic (As). In vitro bioaccessibility studies have demonstrated that cooking the fish muscle decreases MeHg solubility markedly and, as a consequenc...

Current guidelines tend to limit fish consumption based on mercury (Hg) or monomethylmercury (MeHg) content in fish flesh, without considering the presence of antagonist chemical elements that could modulate Hg toxicity. However, it is difficult to assess the potential for antagonistic interactions of these elements since their covariation within m...

The endangered St. Lawrence Estuary (SLE) beluga population is declining and has shown no sign of recovery over the past decades despite several protective measures. Changes in the availability of food resources and exposure to organohalogen contaminants have been suggested as potential factors limiting the recovery of this population. Studies on S...

Our knowledge of the processes leading to the bioaccumulation of rare earth elements (REE) in aquatic biota is limited. As the contamination of freshwater ecosystems by anthropogenic REE have recently been reported, it becomes increasingly urgent to understand how these metals are transferred to freshwater organisms in order to develop appropriate...

In recent decades, mercury concentrations have increased in fish of Great Slave Lake (GSL), a subarctic great lake in northern Canada with important recreational, subsistence, and commercial fisheries. This study characterized habitat use and trophic position of common fish species in GSL near the City of Yellowknife (Northwest Territories, Canada)...

A subarctic fish community in mine-impacted Yellowknife Bay (Great Slave Lake, Northwest Territories, Canada) was investigated for biological and ecological processes controlling arsenic bioaccumulation. Total concentrations of arsenic, antimony, and metals were measured in over 400 fishes representing 13 species, and primary producers and consumer...

The demand for rare earth elements (REEs) has increased since the 1990s leading to the development of many mining projects worldwide. However, less is known about how organisms can handle these metals in natural aquatic systems. Through laboratory experiments, we assessed the chronic toxicity and subcellular fractionation of yttrium (Y), one of the...

Mercury (Hg) is a trace element of particular concern since it is ubiquitous in the environment and because its methylated form (MeHg) readily bioaccumulates and biomagnifies in food webs. This latter process leads to elevated Hg concentrations in fish and may thus induce toxicity. Maternal transfer of bioaccumulated contaminants to offspring is a...

The use of fractionation protocols to determine metal subcellular distribution in aquatic organisms has gained much interest over the last 15 yr, however, accurate separations among the different components of cells are challenging. Subcellular fractions separated with such an approach are operationally defined and a potentially significant differe...

Yelloweye rockfish (Sebastes ruberrimus) is an extremely long-lived species (up to ∼120 years) of fish, which inhabits the coastal waters of Alaska. Due to their long lifespans, yelloweye are known to accumulate high levels of mercury, and potentially other trace elements, in their tissues. Relatively little is known about the subcellular distribut...

Biomolecules involved in handling cytosolic metals in the liver of the yellow perch (Perca flavescens) were characterized in juvenile fish collected from four lakes constituting metal contamination gradients. Using size-exclusion liquid chromatography coupled to an inductively-coupled mass spectrometer (SEC-ICP-MS), we determined metal distribution...

Chromium occurs in aquatic environments under two main redox forms, namely Cr(III) and Cr(VI), with different geochemical and biochemical properties. Cr(VI) readily crosses biological membranes of living organisms and once inside the cells it undergoes a rapid reduction to Cr(III). The route of entry for the latter form is, however, poorly known. U...

Environmental DNA (eDNA) promises to ease non-invasive quantification of fish biomass or abundance, but its integration within conservation and fisheries management is currently limited by a lack of understanding of the influence of eDNA collection method and environmental conditions on eDNA concentrations in water samples. Water temperature is kno...

We characterized the biomolecules involved in handling cytosolic metals in larvae of the phantom midge (Chaoborus) collected from five mining-impacted lakes by determining the distribution of Ag, Cd, Cu, Ni, Tl and Zn among pools of various molecular weights (HMW: high molecular weight, > 670 kDa - 40 kDa; MMW: medium molecular weight, 40 kDa - <1....

We determined the intracellular compartmentalization of the trace metals Ag, As, Cd, Ni, Pb and Tl in the livers of yellow eels collected from the Saint Lawrence River system in Canada (Anguilla rostrata) and in the area of the Gironde estuary in France (Anguilla anguilla). Differential centrifugation, NaOH digestion and thermal shock were used to...

We transplanted larvae of the phantom midge Chaoborus punctipennis from a lake having lower concentrations of Cd and Se (Lake Dasserat) to a more contaminated lake (Lake Dufault) located near to a metal smelter in Rouyn-Noranda, Quebec. Transplanted individuals were held in mesh mesocosms for up to 16 days where they were fed with indigenous contam...

Measurements of the subcellular partitioning of trace metals have been used to predict assimilation efficiencies for metals between trophic levels and to evaluate metal detoxification mechanisms in aquatic organisms. Using field-collected larvae of the insect Chaoborus, we assessed the performance of two preservation protocols, three homogenization...

Larvae of the phantom midge Chaoborus are common and widespread in lakes contaminated by metals derived from mining and smelting activities. To explore how this insect is able to cope with potentially toxic metals, we determined total metal concentrations and subcellular metal partitioning in final-instar Chaoborus punctipennis larvae collected fro...

The presence of petrogenic hydrocarbons was evaluated in surface sediments from the northeastern Havana littoral (Cuba). Different geochemical biomarkers were used to differentiate between biogenic and anthropogenic hydrocarbons. Sediment samples were Soxhlet extracted and analyzed by gas chromatography with flame ionization and mass spectrometer d...

The presence of petrogenic hydrocarbons was evaluated in surface sediments from the northeastern Havana littoral (Cuba). Different geochemical biomarkers were used to differentiate between biogenic and anthropogenic hydrocarbons. Sediment samples were Soxhlet extracted and analyzed by gas chromatography with flame ionization and mass spectrometer d...

As a part of a geochemical study, aliphatic and aromatic hydrocarbons were determined in surficial sediments, from a Cuban coastal zone located in the Northeastern Havana Littoral. Sediment samples were collected at 15 sites in this area, and then extracted and analyzed by gas chromatography with flame ionization and mass spectrometry detectors. To...

As a part of a geochemical study, aliphatic and aromatic hydrocarbons were determined in surficial sediments, from a Cuban coastal zone located in the Northeastern Havana Littoral. Sediment samples were collected at 15 sites in this area, and then extracted and analyzed by gas chromatography with flame ionization and mass spectrometry detectors. To...