These relationships vary depending on the degree to which light and nutrient availability control primary production. This discovery not only affects how we conduct experiments and extrapolate their results to nature, it also suggests conditions under which trophic efficiency will be greatest. Under conditions where fish populations are actively exploited, trophic efficiency will decline with eutrophication. Thus, while eutrophication tends to increase primary production in aquatic ecosystems, it may lead to decreased secondary production.
Experimental artifacts tend to decrease with width of container for experimental ecosystems.
Light attenuation within the water columns of experimental ecosystems depend on the width of the containers, the optical characteristics of wall material and the growth of attached periphyton communities. We have developed quantitative descriptions of these relationships that will provide useful guidelines for future experimentalists. We have developed spatial modeling codes, in collaboration with Dave Scheurer and Bob Gardner, which provide a mechanism for extrapolating results from experiments conducted under mean conditions to natural spatially varying ecosystems. Relative variance among replicate experimental ecosystems tends to decrease with size of containers. Relative variance within experimental ecosystems tends to increase with container size.