Trace metals and Persistent Organic Pollutants concentrations in Narwhals from the Eclipse Sound -PRELIMINARY REPORT- Compiled by: ArctiConnexion Presented by: The Mittimatalik Hunters and Trappers Organization Presented to: the Nunavut Impact Review Board- 2021 Public Hearings on BaffinLand Iron Mines’ Phase 2 proposal January 2021 Introduction Tasiujaq (Eclipse Sound) is the summer gathering, breeding and feeding ground for narwhals (Monodon monoceros) of the Baffin Bay population (Pers. comm. Oomik, 2018; Watt et al., 2013, 2017). Since 2015, Eclipse Sound is used by the BaffinLand Iron Mines company as a shipping corridor for the transportation of six million tonnes of iron ore annually from a port located at the end of Milne Inlet (Qinnguat) and towards international waters (Neary, 2020). The mine is located at approximately 80 km upstream the Milne Inlet port, in the Mary River area. Tailings of open-pit iron mine are known to carry trace metals like mercury, cadmium, lead, arsenic, chromium, nickel, zinc and copper either through the air, the water or soils (Ferreira and Leite, 2015; Li et al., 2021). Trace metals can contaminate terrestrial, aquatic, and marine ecosystems and, through biomagnification and bioaccumulation, can impact various species like caribou, fish and marine mammals, raising concerns on wildlife health and people as these animals are part of traditional diets (Braune et al., 2015; Dietz et al., 2013; Sonne et al., 2018). Despite its important contribution to the diet of Inuit from Mittimatalik (Pond Inlet), the narwhal of the Eclipse sound has received very sparse (and sporadic) attention especially in years following the implementation of mining activities including ore extractions, terrestrial transport, and maritime transport. Elders and hunters from the community have observed the contamination by red dust of the terrestrial environment and the sea-ice near Milne Inlet Port and are concerned by the potential impacts on narwhal health and on people (Pers. comm. Kunnuk, 2018). This study tested the concentration of a series of trace metals in the tissues of narwhals harvested in the Eclipse Sound, as well as the concentration of Persistent Organic Pollutants (POPs). The report presents some preliminary results of the study. Methods Samples of muscle, liver, muktuk (skin), and blubber were sampled from 11 narwhals (3 males, 8 females) harvested by Inuit hunters in the Eclipse Sound and in the Milne Inlet during the month of June and August 2019, respectively. Samples were stored frozen at - 20°C. Traces metals were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) at the Environment Canada, Water Science and Technology Directorate Laboratory in Burlington, Ontario. Blubber samples from four adults and two juveniles were sent for Persistent Organic Pollutants (POPs) analysis to ALS Global (Burlington, Ontario). Organic Chlorinated Pesticides (OCPs) were analyzed following the EPA 1699 (modified) protocol, PolyChlorinated Biphenyls (PCBs) were analyzed by EPA-680, and Brominated Flame Retardants (PBDEs and PBBs) were analyzed by EPA-1614. Both laboratories are accredited through the Canadian Association for Laboratory Accreditation (CALA). Aging results were not yet available and the total length of the animal was used to discriminate juveniles to adult whales (Sonne et al., 2018). Results 1. Mercury and Trace Metals The concentrations of total mercury (THg) measured in 11 narwhals are presented in Figure 1a. The highest THg concentrations were found in the liver ranging 3.0 to 39.0 mg kg-1 and averaging 16.8 ± 11.5 mg kg-1. THg concentrations were 10 to 20 times lower in the muscle (1.28 ± 0.63 mg kg-1) and the Maktaaq (1.05 ± 0.44 mg kg-1). We have not detected any significant effect of gender on THg, but THg was significantly lower in the liver of juveniles (ID#2 and #8) than adults. The concentration of THg in the liver and muscle of adult narwhals sampled in 2019 were apparently higher than concentrations in narwhals sampled in Pond Inlet in the late 1970s and most of the narwhals sampled in Greenland (Figure 1b). The average concentration of THg in liver of adults from Pond Inlet are 3 to 4 times higher in 2019 than in the late 1970s, while the average concentration of THg in muscle were 1.6 time higher in 2019 than in the late 1970s. Fig. 1 – a) Concentration (mg/kg) of total mercury (THg) in muscle, liver and Maktaaq of 11 narwhals sampled in 2019 near Pond Inlet, Nunavut. Gender and life stages are indicated above the bars (F: female adult, M: male adult, and MJ: male juvenile (MJ). b) Comparison of Total mercury mean concentrations (mg/kg) in the muscle and liver of adult narwhals sampled in Pond Inlet in different years and throughout different Arctic locations. Error bars indicate the standard deviation except for NorthWest Greenland where it indicates the standard error. Data source : Pond Inlet 1977-1979 (Wagemann and Muir, 1984), Qikiqtarjuaq (Chan et al., 1995), SW Greenland (Dietz et al., 2004), NW Greenland (Dietz et al., 2004; Sonne et al., 2018), NE Greenland (Sonne et al., 2018). The mean concentration of a series of trace metals measured in 9 adult narwhals are summarized in Table 1. As for THg, trace metals concentrations are generally higher in the liver than in muscle. Iron (Fe) concentrations were especially elevated (299 ± 49 mg kg-1 in muscle and 648 ± 291 mg kg-1 in liver) as well as the cadmium in liver (25.01± 39.90 mg kg-1) and the zinc (40.37 ± 13.27 mg kg-1 in liver and 24.67 ± 5.09 mg kg-1 in muscle). Table 1 - Mean concentration (mg/kg) of trace metals in muscle, liver of adult narwhals (genders combined) sampled in 2019 near Pond Inlet, Nunavut. The trace metals presented here are typical of iron mine releases. Comparing 2019 with the late 1970s, we found no difference between in the mean concentration of Cadmium and Zinc in the muscle and liver of narwhals near Pond Inlet (Figure 2a). In 2019 however, we noticed that the concentration of cadmium was very heterogenous among individuals (Figure 2b). The liver of individual #1 had a very high cadmium concentration (130 mg kg-1) relatively to others, suggesting that some narwhal can bioaccumulate high amount related to their habitat use and feeding choices. Comparison with other areas revealed no distinct trends in cadmium and zinc concentrations (Figure 2a). Fig. 2 – a) Comparison of the mean concentration (mg/kg) of zinc (Zn) and cadmium (Cd) in the muscle (left panels) and liver (right panels) of adult narwhals sampled in Pond Inlet in different years and throughout different Arctic locations. b) Concentration (mg/kg) of cadmium in muscle (left panel) and liver (right panel) of 11 narwhals sampled in 2019 in Pond Inlet. Gender and life stages are indicated above the bars (F: female adult, M: male adult, and MJ: male juvenile (MJ). Data sources are for Qikiqtarjuaq (Chan et al., 1995), SW Greenland (Dietz et al., 2004), NW Greenland (Dietz et al., 2004; Sonne et al., 2018), Pond Inlet in 1977-1979 (Wagemann and Muir, 1984). 2. Persistent Organic Pollutants (POPs) The concentrations of Persistent Organic Pollutants (POPs) measured in 6 narwhals are presented in Figure 3. Overall, the concentrations of the four classes of POPs greatly vary among individuals with no apparent differences among gender. For example, individual #7 (male) and #13 (female) both exhibited high levels of POPs in all four classes. The concentration of total PCBs averaged 2340 ± 1849 ng g-1. Within OCPs, the DDT, the total chlordane-related compounds (CHLOR) and trans-Nonachlor show the highest concentrations and averaged 2466 ± 2321 ng g-1, 1835 ± 1401 ng g-1 and 1230 ± 994 ng g-1, respectively. The concentration of polybromodiphényléthers (PBDE) and Polybrominated biphenyls (PBB) averaged 17 ± 9 ng g-1and 0.32 ± 0.23 ng g-1, respectively. Fig. 3 - Concentration (ng/g) of legacy (a) and new concern (b) Persistent Organic Pollutants (POPs) in the blubber of 6 narwhals sampled in 2019 near Pond Inlet. For the Legacy POPs are presented the Total PolyChlorinated Biphenyls (PCBs)(top-left panel) and some commons OrganoChlorine Pesticides (OCPs) (bottom-left panel). For the POPs of new concern, are presented the Total polybromodiphényléthers (PBDEs)(Top-right panel) and the Total Polybrominated biphenyls (PBB)(Bottom-right corner). Gender and life stages are indicated above the bars (F: female adult, M: male adult, and MJ: male juvenile (MJ). Discussion 1. Mercury and Trace Metals The level of THg found in the liver of narwhals is the result of bioaccumulation over years and is typically higher in adults than juveniles (Loseto et al., 2008), as reported here (Figure 1). Total Hg, as a measure, does not allow for the discrimination of the toxic (Me-Hg) to the nontoxic (HgSe) forms of the mercury in the liver, which require further analyses. High mercury concentration in the liver can lead to hepatic lesions (Sonne et al., 2018) which can affect the metabolism and the neuroendocrine system of marine mammals (Lavery et al., 2009; Rawson et al., 1993; Sonne et al., 2007, 2018) as well as humans (Dietz et al., 2018; Merrill et al., 2001; Sonne et al., 2018). Toothed whales like narwhals are more inclined to bioaccumulate mercury as they cannot excrete this compound through shedding hairs like seals and polar bears can do (Dietz et al., 2013; Sonne et al., 2018). High cadmium concentration in narwhal liver and kidneys can also cause organ damages (Wagemann et al., 1996). Establishing the actual origin of the trace metals measured in the Pond Inlet narwhal tissues is challenging given the many potential sources including mining industry release, but also air and marine transports from southernmost latitudes and/or local release through the melting of permafrost (Braune et al., 2015).