Disposal Facilities at Hamilton Harbour, Lake Ontario, Canada. Martin B. ...... sisted with every component of the field work and Neil Burgess for help with the ...
Arch. Environ. Contam. Toxico!. 25, 234-243 (1993)
ARCHIVES
OF
Environmental Contamination a n d Toxicology © 1993 Springer-Verlag New York Inc.
Accumulation of Organic Contaminants in Sentinel Mallards Utilizing Confmed Disposal Facilities at Hamilton Harbour, Lake Ontario, Canada Martin B. Gebauer I and D. Vaughn Weseloh 2 Canadian Wildlife Service, Environment Canada, Box 5050, 867 Lakeshore Drive, Budington, Ontario, L7R 4A6, Canada
Abstract. Organochlorine analysis was performed on adult and juvenile farm-raised mallards (Anas platyrhynchos) released and collected at three experimental sites in southern Ontario: Hamilton Harbour Confined Disposal Facility (CDF); Winona Sewage Lagoons (SL); and Big Creek Marsh, Canada. Collections were scheduled at 10, 30, and 70 days after release. Hamilton Harbour CDF and Winona SL are known to be contaminated whereas Big Creek Marsh is a relatively clean, natural site. All sites are important resting and feeding areas for migratory and resident waterfowl. Breast muscle concentrations of polychlorobiphenyls (PCBs) in ducks collected 10 days after release (160.8 txg/kg, wet wt) at Hamilton Harbour CDF were more than 5300 times greater than day "0" birds (0.03 txg/kg). All ducks collected from Hamilton Harbour CDF had PCB concentrations exceeding Health and Welfare Canada and United States Food and Drug Administration (FDA) guidelines for edible poultry. Concentrations of DDE (216.9 p~g/kg), hexachlorobenzene (0.9 txg/kg), dieldrin (1.9 ixg/kg), and 1,2,4,5,-tetrachlorobenzene (24.9 ixg/kg) were significantly elevated in ducks utilizing Winona SL. Concentrations of 1,2,3,4-tetrachlorobenzene, mirex, and photomirex were elevated at one or more of the sites. Ducks from Big Creek Marsh had lower contaminant concentrations than ducks from the other study sites. It is not clear whether bioaccumulation of organochlorines at these sites would pose a potential hazard to migratory and resident mallards; however, other duck species such as diving ducks that have more contact with sediments and sediment-derived foods would probably be at much higher risk.
Hamilton Harbour has been designated by the International Joint Commission as an "Area of Concern"; it is contaminated with high sediment concentrations of polychlorobiphenyls (PCBs), polynuclear aromatic hydrocarbons (PAHs), and metals such as lead, copper, chromium, zinc and iron (Poulton 1986; Harlow and Hodson 1988; Mayer and Manning 1990). Sediments that do not meet Ontario Ministry of Environment
1Current Address: Enviro-Pacific Consulting, #224-13900 Hyland Road, Surrey, British Columbia, V3W 2C3, Canada. 2To whom correspondence should be addressed.
(MOE) contaminant guidelines for open water disposal (MOE 1987) are deposited in confined disposal facilities (CDFs). Many CDFs are used intensively by waterbirds both in the breeding season and during migration (White and Cromartie 1985, Gebauer 1991). Studies by Dobos et al. (1991) and Miller (Pers. Comm., 1992, U.S. Fish and Wildlife Service, Minneapolis, MN) showed that contaminants such as PCBs, DDE (2,2-bis-(4- chlorophenyl)-1,1-dichloroethene) and chlordane (cis and trans isomers; 1,2,4,5,6,7,8,8-octachloro2,3,3a,4,7,7a- hexahydro-4,7-methanoindene) accumulated in waterfowl using CDFs. Extrapolating from known contaminant levels in sediments and ducks at Thunder Bay CDF, Dobos et al. (1991) predicted that PCBs would accumulate to 40 Ixg/g (ppm), lipid wt, in ducks utilizing Hamilton Harbour CDF for more than 70 days. Since this value is well above guidelines set for edible poultry by Health and Welfare Canada (1991; 0.5 p~g/g, lipid wt) and FDA (1979; 3.0 p,g/g, lipid wt), our study was initiated to test the prediction by Dobos et al. (1991). Sewage lagoons, such as Winona SL, are also utilized by waterfowl. Several studies at sewage lagoons in the United States have documented waterfowl breeding densities and production far above those found at natural sites (Piest and Sowls 1985, Belanger and Couture 1988). However, sewage lagoons may contain elevated concentrations of various metals including cadmium, zinc, and lead (Goldberg and Yuill 1990). Mallards and Pekin ducks have shown promise as bioindicators of aquatic ecosystem contamination (Rodrigue etal. 1992). The purpose of this study was to determine total PCBs and other organochlorine concentrations in muscle of flightless, farmraised mallards (Anas platyrhynchos) released and later collected at Hamilton Harbour CDF, Winona SL, and a reference area at Big Creek Marsh.
Study Areas Hamilton Harbour Confined Disposal Facility Hamilton Harbour CDF, a disposal site for contaminated dredged sediments, is located in the southeast comer of Burlington Bay, at the west end of Lake Ontario (Figure 1). The site consists of four cells, CDF#1 and #2, which are completely
Contaminants in Sentinel Mallards
235
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filled with dredged sediments, CDF#3, which is partially filled with dredged sediments and has an open water area of approximately 6 ha, and CDF#4, which is completely filled with water and has a surface area of 10.2 ha. During the summer, the dikes and surrounding habitat are used by large numbers of nesting ring-billed gulls (Larus delawarensis) and fewer numbers of Caspian terns (Sterna caspia) and herring gulls (L. argentatus) (Gebauer 1991). A treed area at the northwest end of the site harbours a growing colony of double-crested cormorants (Phalacrocorax auritus) and a declining colony of black- crowned night-herons (Nycticorax nycticorax) (Dobos et al. 1988; Gebauer 1991). During the summer, large numbers of Canada geese (Branta canadensis) and gadwall (Anas strepera) molt here. During migration and until freeze-up in winter, CDF#3 and # 4 are used intensively by large numbers of more than 20 species of migratory waterfowl (Gebauer 1991).
Winona Sewage Lagoons Winona SL are located on the southern shore of Lake Ontario in the town of Winona, near Grimsby, Ontario (Figure 1). The lagoons consist of six cells, four small cells (0.21-0.37 ha) with mechanical aerators, and two larger non-aerated settling ponds (2.25 and 4.1 ha). The facility receives mostly domestic sewage but also some agricultural waste from Arkell Foods, a food processing plant, and AndrOs Wines, a winery, from September to November (J. Adams, pers. comm:, 1992, Public Works, Grimsby, Ontario). Bird species breeding at the lagoons include Canada goose, mallard, gadwall, and spotted sandpiper (Actitis macularia). Diving ducks such as buffiehead (Bucephala albeola) and lesser scaup (Aythya affinis) are common during migration (Canadian Wildlife Service, unpubl, data). Aquatic vegetation, consisting mainly of duckweed (Lemna minor) and milfoil (Ceratophyllum demersum), is present in the two large settling ponds. Cattails (Typha spp.) are established along the edges of the four smaller aerated ponds.
75 i
150 km i
Fig. 1. Location of Hamilton Harbour Contaminated Diposal Facility (CDF), Winona Sewage Lagoons (SL), Big Creek Marsh and Kortright Waterfowl Park in southern Ontario, Canada
Big Creek Marsh A field site was chosen at the Canadian Wildlife Service (CWS) Big Creek Marsh, National Wildlife Area at Long Point, Ontario on the north shore of Lake Erie (Figure 1). The site consists of two diked cells (90 ha) in which the water level is maintained by pumping water from the adjacent marsh. Big Creek Marsh, with its extensive cattail stands, is frequented by several heron species and is an important resting and feeding site for wood duck (Aix sponsa), blue-winged teal (Anas discors), mallard, and other waterfowl during migration. Aquatic vegetation includes arrowhead (Sagittaria latifolia), bulrush (Scirpus spp.), cattail, sedge (Carex spp.), wild rice (Zizania aquatica), swamp loosestrife (Lythrium spp.), smartweed (Blygonum spp.), pond weed, and pond lily (Potamogeton spp.).
Kortright Waterfowl Park Kortright Waterfowl Park, Guelph, Ontario (Figure 1) houses many species of both native and exotic waterfowl. The waterfowl are kept in pens through which tributaries of Hanlon Creek run. The creek receives stormwater discharge from a nearby highway and residential areas. Mallards used in this study were raised in an outdoor pen and fed 18 run grower pellets from aluminum pans and wooden troughs.
Methods and Materials
FieM Studies A total of 10I farm-raised mallards (64 juveniles and 37 adults) was obtained from Kortright Waterfowl Park. Ducks were wing-clipped or pinioned to prevent them from flying. Sex, age, body weight, and flattened wing chord were determined prior to release. Plumage characteristics, bill coloration, and extent of reproductive organ develop-
236
ment were used to determine sex and age. A single, numbered, yellow, livestock ear tag (2 1/2" × 1 3/4", Ketchum MFG Sales Ltd., Guelph, Ontario) was attached to the patagium of each bird. Ducks were transported from Kortright to the study sites in plastic chicken crates. On 30 July 1990, 27 ducks (18 adults, 9 juveniles) were released into CDF#4 at Hamilton Harbour CDF. On 31 July, 28 ducks (3 ad., 25 juv.) were released into the largest settling pond at Winona SL. On 8 August, 30 ducks (8 ad., 22 juv.) were released into Big Creek Marsh. For a day "0" control for Hamilton Harbour CDF and Winona SL, 10 birds (5 ad., 5 juv.), were sacrificed at Kortright on 30-31 July 1990 by asphyxiation with CO2. Six birds (3 ad., 3 juv.) were collected from Kortright on 9 August as a day "0" control for Big Creek Marsh. Juveniles were about 10 weeks old at release whereas the age of adults was undetermined. The lack of uniformity for ratios of adults and juveniles released into the different study sites was unavoidable due to supply limitations. The initial study design called for only juvenile birds. Collections were at 10, 30, and 70 days after release. Exceptions were a day 16 collection at Big Creek Marsh because birds could not be located on day 10, and collections on days 112 and 115 at Winona SL and day 115 at Hamilton Harbour CDF to collect birds remaining at these sites. Sentinel ducks were collected by shotgun with steel shot. Body weight and flattened wing chord were measured on all collected ducks. Ducks were stored in a - 2 0 ° C freezer and shipped frozen to the CWS, National Wildlife Research Centre, Hull, Quebec for analysis.
M.B. Gebauer and D. V. Weseloh
otherwise stated. Geometric means were computed by averaging logtransformed residue values and finding the antilog of the mean. For samples where contaminants were not detected, 1/2 the detection limit was used when computing geometric means. A single duck collected 115 days after release at Winona SL was pooled with the ducks collected at 112 days. Condition indices for each duck were calculated by dividing its weight by flattened wing chord. Body weight, corrected for size (wing length), gives a reasonable indication of the condition of a bird (Owen and Cook 1977). Differences in contaminant concentrations and percent lipid between sites and differences between collections at each site were determined using a Kruskal- Wallis non-parametric one-way ANOVA test for multiple contrasts with a Tukey-type multiple comparison (Zar 1984). Differences in condition index before and after release were determined using a Wilcoxon non-parametric paired sample test (Zar 1984). Non- parametric tests were used because of the small sample sizes with nonnormal distributions. Rate of accumulation was calculated by dividing the difference in contaminant concentrations between day "0" and the collections by the number of days the ducks were exposed.
Results Recovery of Ducks
Laboratory Analysis Breast muscle of the collected mallards was analyzed for 21 compounds: 1,2,4,5- and 1,2,3,4-tetrachlorobenzene (TeCB); pentachlorobenzene (QCB); hexachlorobenzene (HCB); octachlorostyrene (OCS); cis and trans- nonachlor (t-nonachlor; 1-exo, 2-endo, 3 exo 4,5,6,7,8,8-nonachloro-3a,4,7,7a-tetrahydro4,7methanoindane); DDT (1,1,1-trichloro-2,2-bis(p- chlorophenyl) ethane); DDE; DDD (2,2-bis-(4-chlorophenyl)-l,1- dichloroethane); mirex (dodecachlorooctahydro-l,3,4-methano-2H- cyclobuta (c,d) pentalene); photomirex (p-mirex; a photodegradation product of mirex); alpha-, beta-, gamma- hexachlorocyclohexane (HCH); cis and trans-chlordane; oxychlordane (a metabolite of cis and trans-chlordane); heptachlor epoxide (HE; 1,4,5,6,7,8,8-heptachloro-2,3 epoxy-4,7- endomethano 3a,4,7,7a-tetrahydroindene); dieldrin (1,2,3,4,10,10- hexachloro-6,7epoxy- 1,4,4a,5,6,7,8,8a-octahydro- 1,4-endo-5,8-exo- dimethanonaphthalene); and total PCBs. Methods of analysis were according to Won and Turle (1987). Breast muscle was removed and homogenized in a Sorval Omnimixer. The frozen samples were stored in a - 12° C freezer pending analysis. Individual analyses were conducted on all collected birds. The frozen homogenate was thawed and mixed thoroughly, and aliquots were taken for organochlorine and percent moisture analyses. Organochlorine analyses were performed by capillary column GLC/ECD. For organochlorine analysis, all sample fractions (3) after Florisil ® column clean up were evaporated to 1-2 ml prior to injection into the GC. Fraction 1 was adjusted to 5 ml/g each and fractions 2 and 3 were adjusted to 1 mug for injection. A 2 izl of solution was injected into the GC using Hewlett-Packard 7676A auto injector for analysis. The limits of quantification were: 0.0 Ixg/kg for total PCBs, dieldrin, HE, cisnonachlor, cis and trans-chlordane and oxychlordane; 0.2 ~g/kg for QCB and DDE; 0.3 Ixg/kg for 1,2,3,4 HCB; 0.4 Ixg/kg for 1,2,4,5 HCB; and 0.1 p~g/kg for the remainder. Residual values were not corrected for recovery efficiencies which ranged from 90 to 95%.
Statistical Analysis Contaminant concentrations are in txg/kg (ppb) on a wet weight basis. Because of the wide variability in residue concentrations among sampies, we present geometric means rather than arithmetic means, unless
The numbers of ducks observed and collected at each of the sites are presented in Table 1. Ducks released at Winona SL were recovered at a rate of 89% compared to 59% at Hamilton Harbour CDF and 27% at Big Creek Marsh.
Condition and Percent Lipid The average condition of all ducks collected at Hamilton Harbour CDF (X = 37.0, p < 0 . 0 5 ) and Big Creek Marsh (X = 34.9, p < 0 . 0 5 ) was significantly poorer than when ducks were released (40.2 and 39.9, respectively). No difference was observed at Winona SL. Mean condition indices for each collection period are presented in Table 2. At Winona SL, mean percent lipid was significantly lower ( p < 0 . 0 5 ) in ducks from the 30 day collection than at Kortright day " 0 . " No significant variation occurred in percent lipid among any of the other sites and collection dates. All ducks collected from all sites, however, had lower mean percent lipid than at day "0" (Table 3). Thirteen percent of ducks collected from Big Creek Marsh increased in weight compared to 55% at Hamilton Harbour C D F and 89% at Winona SL.
Organochlorine Analysis Adults from the day "0" controls (30, 31 July and 9 August) had significantly higher ( p < 0 . 0 5 ) concentrations of D D E (9.38 Ixg/kg), dieldrin (0.58) and sum PCBs (21.58) than juveniles (2.43, 0.0 and 0.0, respectively). However, significant differences were not observed between adults and juveniles at any of the study sites, and increases in contaminant concentrations were so great that the initial differences between ages were insignificant. Therefore, both adults and juveniles were used when calculating mean contaminant concentrations. No significant differences were observed between sexes.
Contaminantsin SentinelMallards
237
Table 1. Summary of duck collections at Hamilton Harbour CDF, Winona SL, and Big Creek Marsh in 1990 Canada Release Site
date N = # released
Kortright Waterfowl Park
NA
Hamilton Harbour CDF
30 July N = 27
Winona SL
31 July N = 28
Big Creek Marsh
8 Aug N = 30
Collections
Observed
date
# days
# birds
# birds
30/31 July 9 Aug 9 Aug 29 Aug 23 Nov 10 Aug 30 Aug 9 Oct 20 Nov 23 Nov 24 Aug 7 Sep
0 0 10 30 114 10 30 70 112 115 16 30
I0 6 5 5 1 5 5 4 4 1 4 4
NA NA 17 8 1 26 16 12 4 1 10 8
# birds found dead NA NA -2 1 --3 -----
Total collected
Percent recovered
16
100
13
59
22
89
8
27
Table 2. Arithmetic means of condition indices for ducks collected at various time intervals at Hamilton Harbour CDF, Winona SL, and Big Creek Marsh, Canada. Number of samples and range are in brackets
Day 70
Day 114 (CDF) Day 112 and 115 (Winona)
Overall
42.2 (5) (37.3--47.5)
NA
38.4 (1)
40.2 (11)
34.4 (5) (31.7-36.2)
39.2 (5) (33.8-43.7)
NA
39.2 (1)
37.0 (11)*
Before release
42.5 (4) (38.5-50.0)
36.4 (5) (33.1-37.7)
37.3 (4) (34.6-39.0)
41.5 (3) (29.6--50.6)
39.1 (16)
After capture
38.9 (4) (37.5-40.0)
38.3 (5) (36.7-40.7)
39.3 (4) (36.2-41.9)
38.4 (5) (33.8-41.5)
38.7 (18)
Before release
38.0 (4) (36.7-39.4)
41.9 (4) (38.7-45.3)
NA
NA
39.9 (8)
After capture
35.3 (4) (33.1-37.7)
34.4 (4) 30.5-38.1)
NA
NA
34.9 (8)*
Day 10 and 16 (Big Creek)
Day 30
Before release
38.5 (5) (34.8-41.6)
After capture
Site Hamilton Harbour CDF
Winona SL
Big Creek Marsh
* Significantly lower (p < 0.05) than before release
Alpha-, beta-, and gamma-HCH, trans and cis-chlordane and cis-nonachlor were not detected in any samples. The concentrations of organochlorines determined from ducks collected at Kortright, Hamilton Harbour CDF, Winona SL and Big Creek Marsh are summarized in Table 3.
Day "0" Controls vs. Study Sites Eight compounds showed significant increases at one or more of the experimental sites over the levels of the Kortright control (Table 3). T-nonachlor and oxychlordane did not show any significant changes at any of the sites (Table 3). Detectable levels of OCS and QCB were identified in only a single duck (0.7 and 0.9 t~g/kg, respectively) from the day 10 collection at Hamilton Harbour CDF. Heptachlor epoxide was detected in only a single duck (1.3 Ixg/kg) from the day 30 collection at Big Creek Marsh. P-mirex and total PCBs were significantly elevated over the day "0" controls for both the 10 and 30 day collections at Hamilton Harbour CDF (Table 3). Mirex was significantly elevated in only the day 30 birds. All of the ducks collected at
Hamilton Harbour CDF had detectable levels of p-mirex and total PCBs, compared to 10 and 50%, respectively in the day "0" ducks, Concentrations of 1,2,3,4-TeCB were significantly elevated in only the 10 day collection (Table 3). At Winona SL, concentrations of HCB and dieldrin were elevated significantly in the day 70 collection, 1,2,4,5-TeCB and 1,2,3,4- TeCB were elevated in the 112 day collection, and DDE was significantly elevated in the 70 and 112 day collections (Table 3). No compounds were significantly elevated at Big Creek Marsh. Overall, the percent occurrence of all of the contaminants was higher at the study sites than at Kortright (Table 3).
Within Site Variation At Hamilton Harbour CDF, only 1,2,3,4-TeCB was higher in ducks collected at 10 days (p
