Egg loss from Pacific herring spawns in Barkley Sound in 1988 / by C.W. Haegele and J.F. Schweigert. : Fs97-4/2037E-PDF

"Herring spawn was sampled throughout the incubation period in Barkley Sound, British Columbia, at 38 stations on 8 transects extending from the inshore to the offshore limits of egg deposition. Egg predators were identified and enumerated. About 22,000 birds (chiefly gulls and diving ducks), 26 million invertebrates (starfish and snails), and 8 gray whales consumed the eggs from an estimated 271, 1021, and 235 tonnes of herring, respectively. This predation accounted for about 20% of the eggs deposited in the study area. Spawn measurements (sample weight and eggs on vegetation) and observations (% cover of vegetation, plant height, egg layers on vegetation, and eggs on bottom substrate), varied considerably, making it difficult to determine where and how eggs were lost, or to substantiate the egg loss attributed to predators"--Abstract, page iii.

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