Date of Award

2012

Degree Type

Thesis

Degree Name

M.Sc.

Department

Biological Sciences

First Advisor

Corkum, Lynda (Biological Sciences)

Keywords

Ecology.

Rights

CC BY-NC-ND 4.0

Abstract

Bioturbation can cause the burial of eggs in sediments, isolating them from oxygen and consequently preventing development. I investigated the effects of burrowing on egg hatching and nymph development in burrowing mayflies (Hexagenia spp.). First, I examined the effects of burial on egg hatching. More eggs hatched on the sediment's surface than at any other depth. Furthermore, egg burial contributed to greater size variation among hatchlings, possibly from delays in hatching of buried eggs. Subsequently, I investigated the effect of burrowing on the vertical distribution and hatching of eggs within sediments. Reduced hatching and greatest hatchling size variation occurred in trials containing higher densities of nymphs, suggesting that benthic activity facilitates burial of eggs and reduces synchrony of hatching. Under natural conditions, such activities may contribute to the formation of multiple cohorts that characterize Hexagenia populations. These studies show how indirect consequences of ecological engineering can influence life history patterns.

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