Extreme 2002: Mission to the Abyss
Extreme Crew

Dawn Ashbridge

 

Where are you from, and what is your role in Extreme 2002?

I am a microbial ecologist working at the University of Waikato, which is in a city called Hamilton in the North Island of New Zealand. Our university is about a one-hour drive to some very extensive thermal areas — the Yellowstone Park of New Zealand. I have been studying the thermophilic bacteria which grow in these springs for the last 25 years. Last year, Professor Cary spent a year in our laboratory, and consequently I have been invited to join the cruise. This will be my first cruise and my first opportunity to work with deep-sea hyperthermophiles.

What questions are you trying to answer and why? Why is this research important? What are the benefits?

I'll be trying to isolate thermophilic bacteria which are resistant to heavy metals, which are normally regarded as toxic to most organisms. Spring water, and the hydrothermal vents in particular, are rich in heavy metals and so this habitat seems a good place to isolate resistant organisms. The springs in New Zealand do not contain such concentrations of heavy metals, but there is still sufficient to cause concern. We use geothermal energy to generate quite a lot of our electricity, and the waste water from these operations is released into waterways, which provide much of our drinking water supply. One long-term possibility is that we might be able to use thermophilic bacteria to treat the waste water to remove heavy metals — so finding resistant organisms would be the first step to be able to do this.

I have a collaboration under way with geochemists who are expert on the heavy metals of our hot springs, and together we want to try and understand the role the thermophilic bacteria play in the transformations and precipitation of some of these metals. We are interested in some springs in New Zealand that have very high concentrations of antimony and arsenic, for instance. So it will be interesting to compare the types of bacteria resistant to heavy metals from the deep sea with those from our local springs. Many hot-water sources are super-saturated with metals and silicates, so when they cull they form deposits of precipitates. This is another problem for the generation of geothermal energy — the piping gets blocked and pumps used on the water wear out quickly because of all the small mineral and metal particles formed. There is some evidence that thermophilic bacteria contribute to this by acting as nucleating agents, and we want to understand this process better.

What's your background and what lured you into marine science/education?

I became interested in thermophilic bacteria when I first arrived in New Zealand as a new lecturer in microbiology at Waikato 30 years ago. Suprisingly, despite the obvious interest in the thermal springs for tourism and medicinal purposes, no one had looked at their microbial flora, and so this has been my major research interest since. Lately, the focus of my research has been in the evolution of metabolic pathways (particularly glycolysis) since there is some evidence that these pathways, which are now found in all forms of life, might have evolved first in hyperthermophilic bacteria. This field of study is now associated with the emerging field of astrobiology — the possibility that life or metabolism might have evolved on other planets. Professor Cary, on his visit to New Zealand, had similar interests but viewed the hot bubbling mud pools as a possible place where metabolism or life might have originated. These common interests have led to the current collaboration.

Mission and Crew | Seafloor Geology | Creature Feature | High-Tech Tools

Copyright University of Delaware, Oct. 2002.

  University of Delaware
Sponsored by the National Science Foundation, University of Delaware College of Marine and Earth Studies, NOAA Sea Grant