Diatoms are unicellular photosynthetic microbes with cell walls composed of silica dioxide (glass). They are ubiquitous in freshwater aquatic habitats and in the oceans, where they are at the base of the food chain. Globally, diatoms account for about 40% of carbon fixation and oxygen production. There are an estimated 200,000 species worldwide, but to date only about 24,000 species (12%) have been named and described. The Northwest is the least sampled quarter of the US for diatoms and most sampling here has been of polluted waters at lower elevations. Limited sampling of remote, high elevation headwater habitats in Glacier National Park has produced 30 species new to science. Sampling of similar habitats in the Cascades, Northern Rockies, Olympic Range, and elsewhere in the Northwest has the potential to add many more new diatom species and substantially increase our knowledge of the biodiversity, ecology and distribution of species in this very important group of organisms.

Volunteers could participate by collecting samples from remote, high elevation water bodies (lakes, ponds, pools, springs, seeps, fens, bogs, marshes, spray zones, etc.) and recording information about the samples (lat/long, water temperature, type of waterbody, date of collection). It takes only a few minutes to collect a sample. Sampling gear and the samples themselves are lightweight and easily stowed in a pack.  

For this study we are interested in samples from northern California and Nevada, Oregon, Washington, Idaho, Montana, Wyoming, and the western Dakotas.

Permanent slides will be prepared and the diatoms on each slide will be identified to species.  Species new to science will be described and published.

Fossil diatoms brought up in sediment cores are used to estimate ancient water temperatures and a host of other limnological and climatic factors. Because each species has a specific and well documented set of water quality preferences, diatoms are quite useful for reconstructing past climates and changes in trophic status in response to human settlement.

Please note: Special permissions may be required in some protected areas.  Please contact ASC to ask about these if you are traveling in one of these areas.