US EPA

2200999 

Journal Article 

The status of brown pelicans at Anacapa Island in 1975 

Anderson, DW; Jurek, RM; Keith, JO 

1977 

0 

California Fish and Game
ISSN: 0008-1078 

HEEP/77/09959 

63 

1 

4-10 

HEEP COPYRIGHT: BIOL ABS. Data of 1975 on productivity, chemical residues and eggshell thickness of California brown pelicans at Anacapa Island and nearby Santa Cruz Island (USA) suggest that the colonies are recovering from DDT-related reproductive failures. The improved productivity reported for 1974 continued through 1975. However, productivity, residues of DDE, and eggshell thickness in 1975 were not significantly different from those of 1974, suggesting that the rate of improvement has begun to level off. Pelican productivity is still too low for population stability. Chemicals other than DDE are discussed. PCB (polychlorinated biphenyls) were also found at levels of possible concern in brown pelican eggs. PCB levels probably were lower in pelican eggs in 1973-75 than in previous years (1969-72), but recent levels seem to have stabilized. Brown pelican colonies will require continued monitoring for some years to come. The California brown pelican should be retained on California list of endangered fauna until productivity exceeds 1.0 young/nest attempt and the numbers of breeding adults in California waters begin to increase.