Kevin V Brix

Kevin V Brix
EcoTox

Ph.D.

About

132
Publications
18,839
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
3,925
Citations
Introduction
My research interests are in environmental toxicology and environmental physiology. In environmental toxicology, I study the physiological effects of metals on aquatic organisms. In environmental physiology, I focus on two evolutionary transitions; the adaptation of marine organisms invading freshwater environments and the adaption of aquatic organisms to terrestrial environments. In both disciplines, I study aspects of ion regulation, acid-base balance and nitrogen balance.
Additional affiliations
August 2013 - August 2015
University of British Columbia - Vancouver
Position
  • PostDoc Position
November 2012 - August 2013
McMaster University
Position
  • PostDoc Position
May 2008 - November 2012
University of Miami
Position
  • PhD Student
Education
September 2005 - May 2008
University of North Florida
Field of study
  • Biology

Publications

Publications (132)
Article
Full-text available
We investigated how natural dissolved organic matter (DOM) of the Rio Negro (Amazon) affects acute copper (Cu) toxicity to local fish: the cardinal tetra (Paracheirodon axelrodi) and the dwarf cichlid (Apistogramma agassizii). It is established that Cu2+ complexation with DOM decreases Cu bioavailability (and thus toxicity) to aquatic organisms, as...
Article
Effects Based Methods (EBMs) are considered as part of a more integrative strategy for regulating substances of concern under the European Union Water Framework Directive. In general, EBMs have been demonstrated as useful indicators of effects on biota, although links to population and community level effects are sometime uncertain. When EBMs are s...
Article
Full-text available
An increasing number of metal bioavailability models are available for use in setting regulations and conducting risk assessments in aquatic systems. Selection of the most appropriate model is dependent on the user’s needs, but will always benefit from an objective, comparative assessment of the performance of available models. In 2017, an expert w...
Article
Full-text available
Selenium (Se) toxicity to fish is primarily manifested via maternal transfer to the eggs, which may result in adverse effects on larval survival and development. This study assessed the effects of egg Se concentrations derived via maternal transfer on early life stage development, survival, and growth of Arctic grayling (Thymallus arcticus), a salm...
Article
An emerging Multi-Ion Toxicity (MIT) model for assessment of environmental salt pollution is based on the premise that major ion toxicity to aquatic organisms is related to a critical disturbance of the trans-epithelial potential across the gills (ΔTEP), which can be predicted by electrochemical theory. However, the model has never been evaluated p...
Article
Multiple linear regression (MLR) models for predicting chronic aluminum toxicity to a cladoceran (Ceriodaphnia dubia) and a fish (Pimephales promelas) as a function of three toxicity modifying factors (TMFs) – dissolved organic carbon (DOC), pH, and hardness – were previously published. However, the range over which data for these TMFs were availab...
Article
Dissolved nickel (Ni) concentrations inhibiting the growth of juvenile great pond snails (Lymnaea stagnalis) have been documented to vary from about 1 to 200 µg L‐1 Ni. This variability makes L. stagnalis either a moderately sensitive or the most sensitive freshwater species tested to date to chronic Ni exposure. Given the role of sensitive species...
Article
Recently, there has been renewed interest in the development and use of empirical models to predict metal bioavailability and derive protective values for aquatic life. However, there is considerable variability in the conceptual and statistical approaches with which these models have been developed. In the present study, we review case studies of...
Article
Full-text available
Lake Magadi, Kenya, is one of the most extreme aquatic environments on Earth (pH~10, anoxic to hyperoxic, high temperatures). Recently, increased water demand and siltation have threatened the viable hot springs near the margins of the lake where Alcolapia grahami, the only fish surviving in the lake, live. These Lake Magadi tilapia largely depend...
Article
Na+ K+ ATPase (NKA) is crucial to branchial ion transport as it uses the energy from ATP to move Na+ against its electrochemical gradient. When fish encounter extremely dilute environments the energy available from ATP hydrolysis may not be sufficient to overcome thermodynamic constraints on ion transport. Yet many fish species-including zebrafish-...
Article
Full-text available
Killifish (Fundulus heteroclitus) has been extensively used as a model for ion regulation by euryhaline fishes. Na⁺ and Cl⁻ dynamics have been well studied in killifish, but few studies have addressed that of Ca²⁺. Therefore, this study aimed to characterize Ca²⁺ fluxes in freshwater (FW) and seawater (SW)-acclimated killifish, their response to sa...
Article
There is growing interest in the development of mechanistically-based models, such as the Biotic Ligand Model (BLM), for assessing the environmental risk of metal mixtures. However, the derivation of such models requires insights into the mechanisms of multimetal interactions that are often lacking for aquatic organisms. In the present study, we in...
Article
Although metal-mixture toxicity has recently received increasing attention, there is still insufficient knowledge on joint effects occurring in chronic exposures to relatively low metal concentrations. We characterized the chronic toxicity of binary mixtures of six metals (Ag, Cd, Cu, Ni, Pb, and Zn) in 14 day growth tests with juveniles of the met...
Article
Biotic Ligand Models (BLMs) for individual metals improve our ability to regulate metals in the aquatic environment by considering the effects of water quality parameters (ionic composition, pH, DOC) on metal bioavailability. However, in natural aquatic systems, organisms are often simultaneously exposed to multiple metals and these interactions ar...
Article
The bioavailability of aluminum (Al) to freshwater aquatic organisms varies as a function of several water chemistry parameters, including pH, dissolved organic carbon (DOC), and water hardness. We evaluated the ability of multiple linear regression (MLR) models to predict chronic Al toxicity to a green alga (Pseudokirchneriella subcapitata), a cla...
Article
The US Environmental Protection Agency's (USEPA's) current ambient water quality criteria (AWQC) for lead (Pb) in freshwater were developed in 1984. The criteria are adjusted for hardness, but more recent studies have demonstrated that other parameters, especially dissolved organic carbon (DOC) and pH, have a much stronger influence on Pb bioavaila...
Article
Over the past 20 years there has been a concerted effort to develop Biotic Ligand Models (BLMs) for the derivation of site-specific water quality criteria (WQC) for metals. BLMs are now available for a range of metals and are widely applied in ecological risk assessments. In Europe, both regional and national water quality criteria are under develo...
Article
The Gulf toadfish (Opsanus beta) has a fully functional ornithine urea cycle (O-UC) that allows it to excrete nitrogenous waste in the form of urea. Interestingly, urea is excreted in a pulse across the gill that lasts 1-3 h and occurs once or twice a day. Both the stress hormone, cortisol, and the neurotransmitter, serotonin (5-HT) are involved in...
Article
There is consensus that fish are the most sensitive aquatic organisms to selenium (Se) and that Se concentrations in fish tissue are the most reliable indicators of potential toxicity. Differences in Se speciation, biological productivity, Se concentration, and parameters that affect Se bioavailability (e.g., sulphate), may influence the relationsh...
Article
Full-text available
Insect larvae are reported to be a major component of the simple but highly productive trophic web found in Lake Magadi (Kenya, Africa), which is considered to be one of the most extreme aquatic environments on Earth. Previous studies show that fish must display biochemical and physiological adjustments to thrive under the extreme conditions of the...
Article
Current ecological risk assessment and water quality regulation for nickel (Ni) use mechanistically-based, predictive tools such as Biotic Ligand Models (BLMs). However, despite many detailed studies, the precise mechanism(s) of Ni toxicity to aquatic organisms remains elusive. This uncertainty in the mechanism(s) of action for Ni has led to concer...
Article
The complex chemistry of iron (Fe) at circumneutral pH in oxygenated waters and the poor correlation between ecotoxicity results in laboratory and natural waters, has led to regulatory approaches for iron based on field studies (United States Environmental Protection Agency Water Quality Criteria and European Union Water Framework Directive proposa...
Article
Full-text available
The Magadi tilapia, Alcolapia grahami, a small cichlid fish of Lake Magadi, Kenya lives in one of the most challenging aquatic environments on earth, characterized by very high alkalinity, unusual water chemistry, and extreme O2, ROS, and temperature regimes. In contrast to most fishes which live at temperatures substantially lower than the 36–40 °...
Article
We evaluated the use of biokinetic models to predict selenium (Se) bioaccumulation into model food chains after short-term pulses of selenate or selenite into water. Both periphyton- and phytoplankton-based food chains were modeled, with Se trophically transferred to invertebrates and then to fish. Whole-body fish Se concentrations were predicted b...
Article
Full-text available
This paper presents long-term monitoring data for 19 elements with a focus on arsenic (As), copper (Cu), and selenium (Se), in surface water (2002-2011), brine shrimp (2001-2011), and brine flies (1995-1996) collected from Great Salt Lake (GSL, Utah, USA). In open surface waters, mean (±standard deviation [SD]; range; n) As concentrations were 112...
Article
While it is increasingly being recognized that biotic ligand models (BLM) are valuable in the risk assessment of metals in aquatic systems, the development of chronic BLMs for lead (Pb) has been less advanced than for other metals. Here, we investigated the univariate effects of Ca and pH on chronic reproductive toxicity of Pb to Ceriodaphnia dubia...
Article
The relationship between microevolution and macroevolution is a topic of fundamental importance in evolutionary biology. The increasing accessibility of genomic tools is making the hunt for genes that underlie evolutionary divergence more tractable and, when combined with physiological approaches, provides exceptional power to elucidate the causal...
Article
Full-text available
Trophic transfer (biotransference—Dallinger et al. 1987) results from passage of a contaminant through food chains as a result of uptake only from water (bioconcentration), only from diet (dietary accumulation), or from a combination of these (bioaccumulation) (Biddinger and Gloss 1984; Davis and Foster 1958; Macek et al. 1979; Suedel et al. 1994)....
Article
Full-text available
This study provided an initial characterization of Na + uptake in saline freshwater by the endangered pupfish, Cyprinodon macularius. This species occurs only in several saline water systems in the southwestern USA and northern Mexico, where salinity is largely controlled by water-management practices. Consequently, understanding the osmoregulatory...
Article
The euryhaline fish Cyprinodon variegatus variegatus (Cvv) is capable of tolerating ambient salinities ranging from 0.3 to 167 g l-1 , but incapable of long-term survival in freshwater (< 2 mM Na+ ). However, a population of this species, now designated as a subspecies (Cyprinodon variegatus hubbsi; Cvh), has been isolated in several freshwater (0....
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Article
Full-text available
The euryhaline fish Cyprinodon variegatus variegatus is capable of tolerating ambient salinities ranging from 0.3 to 160 PSU, but is incapable of long-term survival in freshwater (<2 mmol l(-1) Na(+)). A population isolated in several freshwater (0.4-1 mmol l(-1) Na(+)) lakes in central Florida is now designated as a subspecies (Cyprinodon variegat...
Article
Full-text available
Previous studies have demonstrated that the euryhaline copepod Acartia tonsa is extremely sensitive to dietborne silver (Ag) exposure, with a 20 % inhibition (EC(20)) of survival occurring when copepods are fed algae with 1.6 μg g(-1) dry weight (dw) Ag, corresponding to a waterborne Ag concentration of 0.46 μg l(-1) Ag. In contrast, 43 μg l(-1) Ag...
Article
The European Union's Existing Substances regulation (EEC 793/93) was developed to assess the ecological risks posed by chemical substances such as Ni and includes the assessment of secondary poisoning risks. The basic structure of this secondary poisoning risk assessment followed the Technical Guidance Document on Risk Assessment and thus included...
Article
The current study examined the chronic toxicity of lead (Pb) to three invertebrate species: the cladoceran Ceriodaphnia dubia, the snail Lymnaea stagnalis and the rotifer Philodina rapida. The test media consisted of natural waters from across North America, varying in pertinent water chemistry parameters including dissolved organic carbon (DOC), c...
Article
Laboratory studies have traditionally indicated that aquatic insects are relatively insensitive to metals while field studies have suggested them to be among the most sensitive aquatic invertebrate taxa. We reviewed and synthesized available studies in the literature to critically assess why this discrepancy exists. Despite the intense effort to st...