Purchasing an autoclave and a cryogenic freezer to foster research on the effects of environmental change on plankton

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Because of decades of acid deposition, and multiple cycles of logging and forest re-growth, calcium (Ca) concentrations are currently falling in soils and lakes in Eastern Canada. In consequence, populations of Ca-rich biota, such as the planktonic water flea, Daphnia, are declining. Because Daphnia are important contributors to pelagic biodiversity, and conduits of food and energy to fish, their losses are of concern to aquatic ecologists and informed lake managers. The response of Daphniids to Ca decline varies with their nutritional status, and likely with exposure to other stressors, such as metals. Thus to quantify the damaging Ca thresholds, we must pay attention in our experiments to other stressors such as nutrients and metals. To identify the mechanisms of effect, we also need controlled laboratory bioassays, followed by research at both the biochemical and molecular (i.e. gene expression) levels. York University's Field Laboratory for the Assessment of Multiple Ecological Stressors (FLAMES lab) is well equipped to conduct the needed multiple-stressor bioassays on daphniids, but does not have the needed equipment to control bacterial levels in bioassay media, nor to maintain samples in a stable condition for subsequent molecular assays. I request an autoclave and a cryogenic freezer to fill these needs. This equipment will permit much improved control of bacterial levels in assay media, and will foster research on the mechanisms underlying low Ca stress on daphniids in an increasing complex world, i.e. with warming waters, lower phosphorus and metals. This equipment will foster the interdisciplinary training of 4 young scientists in the newly recognized, widespread threat of environmental calcium decline. Canada is uniquely blessed with freshwater lakes, but their protection and management requires new tools to deal with newly recognized complexities. The equipment in this application will foster the practical development of toxicogenomics, a field poised to produce a whole new box of assessment tools, tools needed to select from among multiple plausible causes of environmental damage, those actual causes of disturbance that warrant management intervention.