Residues (petroleum), hydrocracked

Toxicity to birds

Additional information

In a key one-generation avian reproduction test (OECD 206; KS = 2), mallard ducks (Anas platyrhynchos; 5/sex/dose) were exposed to weathered North Slope crude oil (WEVC) at concentrations of 0; 200; 2000; and 20,000 mg WEVC/ kg diet ad libitum for 22 weeks. At 8 weeks animals were photostimulated to induce reproduction. Eggs were incubated and hatchlings were observed for two weeks. At the end of the study animals were sacrificed. Adult breeder parameters statistically measured included body weights, growth, feed consumption, feed wastage, clinical chemistry, haematology, and organ weights. Reproduction parameters measured included egg production, cracked eggs, set eggs, fertile eggs, viable eggs, eggs hatched, eggshell thickness, and eggshell strength. Hatchling parameters evaluated were the number of 14 -day survivors, hatchling body weights, and 14-day survivor body weights.

 

Two female ducks died in the 200 and 20,000 mg WEVC/kg diet groups but based on necropsy these mortalities were deemed to not be substance-related. Chronic ingestion of diets containing up to 20,000 mg WEVC/kg diet did not cause overt mortality or grossly observable signs of toxicity to mallards. No adverse effects were noted in the ability of parental birds to produce viable embryos, and no apparent effects were seen on the hatchability of these eggs, or on the survival or fitness of the hatchlings. Slight reductions in eggshell thickness and strength were observed in the 20,000 mg/kg diet group; however, given the magnitude of the observed change, it is likely of minimal biological significance. It was determined that the No Observable Advers Effect Level (NOAEL) was 20,000 mg WEVC/kg diet (Stubblefield et al., 1995)

 

A number of supporting non-standard laboratory studies have been conducted to evaluate the effect of Heavy Fuel Oil contamination on egg hatchability. Mallard duck (Ana platyrhynchos) eggs treated with 5 μl or more of Bunker C applied to the shells showed drastically reduced survival and hatching success reduced to 36% (KS = 2; Szaro,1979). Ducklings which hatched from coated eggs, however, showed no significant weight differences from controls.

 

Fewer eggs were produced by Japanese quail (Coturnix coturnix japonica) exposed to a single dose of 200 mg of Bunker C fuel oil in the first 4 days following its administration. Hatchability of the eggs was also drastically reduced but returned to normal after 4 days. The NOAEL was determined to be 100 mg Bunker C fuel oil (KS = 2; Grau et al., 1977).

 

Mallard ducks exposed to treatments of Bunker C fuel oil ranging from 1 to 12 mL/kg/ day for 28 days by gizzard applications showed no effects on mortality or body weight. The NOAEL was determined to be 12 mL/kg/day (KS = 2; Rocke et al., 1984).