Population impacts in white sucker (Catostomus commersonii) exposed to oil sands–derived contaminants in the Athabasca River

Abstract

Biological and chemical endpoints were measured in white sucker collected downstream of Athabasca oil sands developments (AB, Canada) and compared with those at Calling Lake (AB, Canada), a reference location upstream of the Athabasca oil sands deposit. Naphthenic acid concentrations were also measured at 14 sites in the Athabasca River watershed. Concentrations of naphthenic acids were elevated in tributaries adjacent to oil sands mining developments. Tributary naphthenic acid profiles were more similar to aged oil sands process water than samples from the Athabasca River, suggesting an influence of tailings in the tributaries. White sucker showed higher energy storage in the Athabasca River as indicated by significantly higher condition and liver size. White sucker were not investing that energy into reproductive effort as measured by gonad size and fecundity, which were significantly reduced relative to the reference location. White sucker showed increased exposure to polycyclic aromatic hydrocarbons as indicated by hepatic cytochrome P4501A (CYP1A) activity and fluorescent bile metabolites, as well as higher concentrations of naphthenic acids in bile. Cadmium, copper, nickel, and selenium were also elevated in white sucker liver tissue compared with the reference location. Based on the exposure profile and response pattern observed, effects on energy storage and utilization in white sucker from the Athabasca River most likely resulted from exposure to polycyclic aromatic hydrocarbons derived from petrogenic and pyrolytic sources. Environ Toxicol Chem 2017;36:2058-2067. © 2017 SETAC.

Increased size and relative abundance of migratory fishes observed near the Athabasca oil sands

“…Patterns in the relative abundance of white sucker compared with the others diverged in 2009. This suggests that some alterations in some of the factors affecting the relative abundances of fishes in the lower Athabasca basin occurred within the last decade, and indicate the importance of considering ecology in monitoring studies of migratory species (Arens et al 2017). More specifically, changes occur most frequently in species that migrate from Lake Athabasca into the oil sands area to spawn.…”

“…Acute toxicity to early life stages of fish may be a relevant indicator, but documenting changes using this measurement can be challenging in field settings. Changes in fish associated with chemical stressors have also been observed during field studies, but the detected differences are largely limited to the induction of biochemical markers of exposure, occurrence of PACs in fish muscle, PAC biotransformation products, and changes in reproductive physiology (Tetreault et al 2003;Ohiozebau et al 2016Ohiozebau et al , 2017Arens et al 2017).…”

Aquatic Ecosystem Health Assessment of the Athabasca River Mainstem Oil Sands Area Using White Sucker Health

“…They also demonstrated reduced investment of energy into reproductive development (gonad size and fecundity) which was not seen in the studies here. This may be due to the fact that this study collected resident fish from the Athabasca River in the fall of the year, and Arens et al [12] collected fish during the spawning period in the spring. Earlier monitoring programs in the area collected fish community data on the mainstem Athabasca River as well as fish communities that use tributary streams for spawning in the spring (Regional Aquatic Monitoring Program).…”

“…It is recommended to evaluate whether improvements in fish health identified in year three are confirmed in the next sampling period. Arens et al [12] collected spawning white sucker from the Muskeg River, a tributary of the Athabasca River very close to the AR DS M4 location, and also demonstrated increased energy storage in terms of condition factor and liver size relative to fish collected from a lake upstream of the oil sands deposit. They also demonstrated reduced investment of energy into reproductive development (gonad size and fecundity) which was not seen in the studies here.…”

Oogenesis is accompanied by cyclic morphological changes in hepatocytes of Neotropical freshwater fish Piabina argentea

“…However, this low absolute fecundity may also be related to an environmental impact on oogenesis (Murua & Saborido‐Rey, ). In fact, the presence of pollutants in the aquatic environment could be a stressor factor that affects the growth of oocytes and, then the quality of ova as well as the reproductive potential (fecundity) (Arens et al., ). The Itapecerica river, where the P. argentea was caught, receives generalized pollution from organic and industrial effluents as a result of poorly planned municipal sewage systems (IGAM, ).…”