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To describe the spatial and temporal distribution of 16 parent PAHs in edible fish tissue of northern pike (Exos luscious), burbot (Lota lota), goldeye (Hiodon alosoides), whitefish (Coregonus clupeaformis), and walleye (Sander vitreus) at three locations on the Athabasca River and two locations on the Slave River, sampled in summer and fall of 2011, and in the spring of 2012.

OBJECTIVE

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous compounds, which originate from both natural (e.g., forest fires, natural hydrocarbon seeps) and anthropogenic sources (e.g., combustion of fossil fuels, coal burning, use of oil for cooking and heating). Their presence in the Athabasca basin is a result of a highly dynamic system with natural and anthropogenic inputs. Parts of the Athabasca River and its tributaries, which over geological time have incised into the oil sands deposits, receive natural inflows of PAHs from the McMurray Formation (Dowdeswell et al. 2010, Akre et al. 2004). The development of oil sands in the area is also a source of PAHs (Kelly et al. 2009, Parajulee, Wania 2014). Here we report on concentrations of PAHs in the muscle of fish collected in the Athabasca and Slave rivers. Fish species were chosen based on their abundance along the basin, and their dietary significance to communities in the area. They are therefore of interest in monitoring contaminant levels and in estimating potential human health effects.

INTRODUCTION

METHODS

RESULTS: PARENT PAHs

RESULTS: ALKYLATED PAHs

CONCLUSIONS •The results show that measurable levels were detected across spatial and temporal studies •Data suggest fishes from upstream portions of the Athabasca River, which were nearer to locations where oil sands are extracted and upgraded, contained greater concentrations of individual PAHs in muscle than did fishes from the Slave River •The alkylation fingerprints indicate that fishes in the Athabasca basin received PAHs from petrogenic and pyrolytic sources with higher input from petrogenic sources •Seasonal variations were also observed •Further studies to determine the concentration of metabolized PAHs in bile, risk to human consumers, and degree of alkylation are ongoing ACKNOWLEDGEMENTS First Nations and Metis communities of Fort Resolution, Fort Smith, Fort Chipewyan, Fort McKay and Fort McMurray, and numerous Provincial and Federal agencies are acknowledged for their assistance during the sampling. Portions of this study were funded by the Boreal Songbird Initiative (BSI); Aboriginal Affairs and Northern Development Canada (AANDC) and the Government of the Northwest Territories. PDJ is a Northern Environmental Toxicology Initiative Faculty member at the University of Saskatchewan. EO was supported by a New Faculty Scholarship to PDJ from the University of Saskatchewan.

The Presence of Polycyclic Aromatic Hydrocarbons in Edible Fish Tissue from the Athabasca/Slave River System, Canada

E. Ohiozebau1, B. Tendler2, A. Hill2, G. Codling2, J. Giesy2,3,4,5,6, E. Kelly7, P. Jones1,2

Fishes were collected in the summer and fall of 2011 and spring 2012 in cooperation with First Nations fishers, and regional and federal agencies. A total of 425 fishes of 5 species were collected. Bile and muscle tissues were collected for PAH measurement. 15 g wet mass (wm) of fish muscle was extracted for 24 hr in a Soxhlet apparatus with 250 ml dichloromethane before concentration to 0.1 ml under a stream of nitrogen. The extract was then analyzed by GC-MS using a Hewlett Packard (HP) 7890A GC fitted with 60 m, 0.25 mm i.d. DP-5 silica capillary column and a HP 7683 series autosampler in selective ion monitoring (SIM) mode.

Fig.7: Extraction using soxhlet apparatus

Location Species Length (cm) Weight (g) LSI Gonad (g) Fort

Resolution Burbot 62.1 1638 7.7 22.3 Goldeye 37.3 596 1.4 52.1 Jackfish 66.3 2354 2.1 76.7 Walleye 47.4 1271 1.9 22.6 Whitefish 40.8 938 1.3 12.0

Fort Smith Burbot 48.6 879 1.9 47.5 Goldeye 36.2 568 1.5 43.3 Jackfish 65.9 2534 1.9 130 Walleye 46.5 1245 1.3 89.2 Whitefish 40.8 953 0.8 27.0

Fort Chipewyan

Burbot 50.0 1040 4.1 43.6 Goldeye 36.4 566 1.4 20.8 Jackfish 68.0 2652 1.3 31.7 Walleye 50.3 1374 1.5 25.3 Whitefish 41.1 1217 1.3 23.0

Fort McKay Burbot 55.2 1075 2.1 82.9 Goldeye 33.6 497 1.4 16.2 Jackfish 61.4 2098 1.7 42.6 Walleye 48.0 1056 1.4 31.5 Whitefish 40.0 1096 0.9 28.5

Fort McMurray

Burbot 39.6 420 6.0 2.4 Goldeye 35.7 558 1.2 23.6 Jackfish 65.0 2753 1.7 73.6 Walleye 47.3 1326 1.4 22.2 Whitefish 41.8 1160 1.0 17.1

Burbot Goldeye Jackfish Walleye Whitefish

Fort Resolution 14.9 20.3 7.8 8.4 11.9

Fort Smith 22.8 14.5 10.8 24.2 13.9

Fort Chipewyan 29.2 16.3 15.9 22.4 26.8

Fort McKay 24.4 43.4 58.8 54.4 61.1

Fort McMurray 63.8 42.6 52.5 33.5 56.6

Burbot

(48)

Goldeye

(133

)

Jackfis

h (12

7)

Walleye

(128)

Whitefish

(119

)

Selected Species

0

5

10

15

20

25

30

35

40

45

50

Conc

entra

tion

(ng/

g)

Fall (1

89)

Spring

(186

)

Summer

(196)

Seasons

0

10

20

30

40

50

PAH

Conc

entra

tion

(ng/

g)AUTHOR AFFLIATIONS

1School of Environment & Sustainability, University of Saskatchewan, Saskatoon, Canada 2Toxicology Centre, University of Saskatchewan, Saskatoon, Canada 3Dept. of Biomedical Veterinary Sciences, University of Saskatchewan, Saskatoon, Canada 4Dept. of Biology and Chemistry, City University of Hong Kong, Hong Kong, SAR, China 5School of Biological Sciences, University of Hong Kong, Hong Kong, SAR, China 6State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People’s Republic of China7Environment and Natural Resources, Government of the Northwest Territories, Canada. Email Contact: ehimai.ohiozebau@usask.ca

Table 1: Average morphological characteristics of the sampled species

Table 2: Average concentration of PAHs in sampled Fishes (ng/g, wm)

Fig.9: PAH Concentration in Jackfish

SAMPLING LOCATIONS

Fig. 1: Sampling locations along the Athabasca/Slave River, Canada

Fort Resolution

Fort Smith

Fort Chipewyan

Fort McKay

Fort McMurray

Fig 8: Spatial variation

Fig 10: Seasonal variation Fig 11: Species variation

Concentrations of PAHs in muscle of the 425 sampled fishes contained a mean concentration of 30 ng/g ∑PAH, wm. Mean concentrations for all species, locations, and seasons of ∑2-ring, ∑3-ring, ∑4-ring, ∑5-ring PAHs and ∑6-ring PAHs were 5.8, 10.7, 7.2, 4.6 and 1.5 n g / g , w m , r e s p e c t i v e l y . Concentrations of ∑PAHs in species collected in the vicinity of Fort McKay, varied among seasons, ranging from 11 ng/g, wm (burbot, summer) to 1.2x102 ng/g, wm (burbot, spring) with mean of 48 ng/g, wm. Concentrations of ∑PAHs in fishes collected in the vicinity of Fort Resolution also varied among species and season and ranged from 4.3 ng/g, wm (whitefish, summer) to 33 ng/g, wm (goldeye, summer) with a mean of 13 ng/g, wm. Whitefish contained the greatest concentration at al l locations and seasons with a mean (locations, seasons) of 32 ng/g, wm.

Figure 12: The distribution of the C0–C4 alkylated PAHs: a) naphthalene, b) fluorene, c) pheanthrene/anthracene, showing the preponderance of C3. d)fluoranthene, e) chrysene, showing the preponderance of C4.

0

14

28

42

56

70

Con

cent

ratio

n (n

g/g)

Con

cent

ratio

n (n

g/g)