Past Abstract Details


2010 poster

Impact of boot sole type on the transport and survivability of *Didymosphenia geminata*

Alexander, Katie 1 ; Turner, Jane 2 ; Pugh, Evan 3 ; Cullis, James 4 ; McKnight, Diane 5

1 CU Boulder - ENVS
2 CU Boulder - CVEN
3 CU Boulder - GEOL
4 CU Boulder - CVEN

Didymosphenia geminata, a freshwater diatom, is growing in significance as a nuisance algal species in lotic systems of North America, New Zealand, Europe and Asia. D. geminata is capable of fully covering stream beds with thick mats composed of stalk material, significantly impacting the sustainability of stream ecosystems, water supply infrastructure and recreational activities. Humans are a major factor in the spread of this nuisance species. Felt-soled waders, in particular, have been given much of the blame, and as a result, have been banned in New Zealand and Alaska. The fishing gear manufacturer SIMMS committed to phasing out all felt soled waders by 2010 and replacing them with a new line of Vibram® StreamTread boots. The aim of this study was to determine whether the new Vibram® soles were more effective at preventing the spreading D. geminata cells than the more traditional options of felt or rubber. The boots were ranked based upon transferability and survivability of cells. Transferability was quantified by comparing total cells found on the sole of each boot, compared to the environmental cell density. Survivability measurements were based on changes in live-to-dead cell ratios after a 36-hour period. The results showed that the new Vibram® Streamtread soles carried significantly fewer cells, and that the percentage of live cells was lower after 36 hours. In contrast, the felt soles not only transported more cells, but the percentage of live cells actually increased after 36 hours. It is hypothesized that reproduction may have occurred because of the similarity between felt material and natural D. geminata mats. While these results confirm Vibram®’s superiority when compared to felt and rubber soled boots, users still need to take proper precautions and follow recommended methods for decontamination if they wish to limit the spread of D. geminata. These results give support to manufacturers such as SIMMS, to water resources managers involved in policy decisions to ban felt soled waders, and to recreational users who to choose to make the switch to a more environmental-conscious product.

Crippen, R.W., & J.L. Perrier, 1974, The use of Neutral Red and Evans Blue for live-dead determinations of marine plankon: Stain Technology, v.49, p. 97-104.

Environmental Protection Agency Region 8, 2009, Didymosphenia geminata: a nuisance freshwater algae. Retrieved November 2009, from

Kilroy, C., et. al., 2006, Studies on the survivability of the invasive diatom Didymosphenia geminata under a range of environmental conditions, BioSecurity New Zealand, Christchurch: NIWA.






Site built and hosted by INSTAAR