Fate of Dead Fish in a Small Lake
1998; University of Notre Dame; Volume: 140; Issue: 1 Linguagem: Inglês
10.1674/0003-0031(1998)140[0192
ISSN1938-4238
Autores Tópico(s)Turtle Biology and Conservation
ResumoObservations and experiments were conducted on natural mortality of fish at a small Michigan lake during spring. During an extensive fish die-off in 1989, only 22% (202) of the dead fish were found even though an estimated 10% (918) of the fish population >150 mm TL died. Scavengers, principally yellow bullheads (Ameiurus natalis) and turtles feeding in the littoral zone, claimed approximately 60% of the dead fish that year and 82% in another year with a smaller die-off. The remainder decomposed in 6–34 days. The long-standing mystery of why so few large dead fish are noticed in lakes, despite high annual natural mortality rates of abundant fish populations, was adequately explained by unseen decomposition in deep water and the ability of resident scavengers to keep up with the supply of dead fish except during unusually concentrated fish die-offs.
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