Ohlendorf, H. M., Custer, T. W., Lowe, R. W., Rigney, M., and Cromartie, E.,
1988, Organochlorines and mercury in eggs of coastal terns and herons in
California, USA: Colonial Waterbirds, v. 11, no. 1, p. 85-94.

Abstract:

In San Francisco Bay, California, USA, concentrations of DDE and mercury in eggs
differed among  Caspian tern, forster's tern, black-crowned night-heron, and snowy
egret (Sterna caspia, S. forsteri, Nycticorax  nycticorax , and Egretta thula ,
respectively) in 1982. Geometric mean DDE concentrations were higher (P <  0.05)
in caspian tern eggs (6.93 ppm, wet weight) than in eggs of other species (1.92-2.84
ppm). Mean mercury  concentrations were significantly greater in Caspian tern
(1.25 ppm) and Forster's tern (0.90 ppm) eggs than in  night-herons (0.41 ppm), but
night-heron eggs contained higher concentrations of mercury than did the eggs of 
snowy egrets (0.21 ppm).

Keywords:

mercury, DDE, bird-eggs, marine-pollution, Ave, organochlorine-compounds,
reproduction, USA, California, Sterna-caspia, Sterna-forsteri,
Nycticorax-nycticorax, Egretta-thula, INE, San-Francisco-Bay, pollution-effects,
sexual-reproduction, bioaccumulation, effects-on; eggshell-thickness