Mark S. Wilson, Ph.D.
Life in Boiling Acid
Lassen Volcanic National Park in
northern California is situated at the southern end of the Cascade Range.
Within park boundaries are several high-elevation, acid-sulfate, low chloride
springs characteristic of vapor-dominated hydrothermal systems. The hot springs, steaming
fumaroles, boiling mudpots, and sulfurous vents of Lassen are some of the most
extreme life-supporting environments on earth with temperatures from
50˚C-145˚C, and pH from 0-3. The park is relatively understudied, and
very few culture and molecular studies of microbes at LVNP have been
published. Our preliminary work
indicates there are abundant novel microorganisms in the high-T, acidic
geothermal features in Lassen Volcanic National Park.
Boiling Springs Lake Thermal Area is a
pristine, high-elevation (1805 m) designated wilderness area of LVNP that
includes a large, acidic (pH 2), hot (52˚C) lake known as Boiling
Springs Lake, several weakly pressurized fumaroles, and
small hot springs and mud pots of variable T and pH. Boiling Springs Lake
occurs in an area of weakened rock along a fault zone, and is geologically and
chemically distinct from caldera-type volcanic lakes typified by the Uzon
Caldera (Kamchatka, Russia) and Frying Pan Lake (New Zealand), and from high
chloride, lower sulfate features characteristic of the liquid-dominated
geothermal systems in Yellowstone National Park. Boiling Springs Lake is approximately 1/3 the size, and
significantly more acidic than the world's largest hot spring - Frying Pan lake
(pH 3.5, 50˚C).
Boiling Springs Lake, with some of our sampling sites indicated and
Lassen Peak visible in the background
The
temperature, pH, and geothermal inputs of BSL make it conducive for
interactions among active communities of Bacteria, Archaea, microbial Eukarya,
and viruses, while almost certainly excluding metazoans. BSL has the advantages
of being accessible (~3 km from trailhead), and tractable for research, since
we can safely sample from various locations around the entire lake margin. The
existence of pH, T, and geochemical gradients created by hot springs that are
physically connected to this large, high temperature, acidic lake make BSL an
exciting research site.
Project Goals
Prior studies of acidic, warm
lakes and hot springs have largely focused on organismal autecology or
biogeography, examining specific environmental adaptations, but not on
interactions between organisms. In this project we are attempting to combine
expertise in a multidisciplinary team to explicitly study the synecology of the
unique, probably exclusively microbial ecosystem that BSL provides. We seek
to develop an understanding of the abundance, distribution, and diversity of
prokaryotes, eukaryotes and viruses in two thermally distinct regions of BSL,
and to examine the stability of the populations over time. Additionally, we are trying to examine
the contributions of photosynthesis and chemosynthesis to the productivity of
BSL, and to initiate studies on the relative importance of top-down vs.
bottom-up controls on the diversity and function of this microbial community.
To
address these goals, we use a combination of field, molecular, and
culture-based studies. Siering and Wilson
(Humboldt State University, HSU) provide strengths in prokaryotic molecular
ecology, isolation, characterization and microscopy. Wolfe (Chico State University, CSUC) is experienced in
limnology and oceanography, eukaryotic molecular ecology, and isolation of
protists and characterization of their grazing. Stedman (Portland State University, PSU) provides
strengths in viral genetics, enrichment and cultivation of thermophilic and
acidophilic Archaea.
Undergraduate
students sampling at Boiling Springs Lake in Lassen Volcanic National Park. Several undergraduates have been and
are involved in this research project.
Dr. Patricia Siering has an introductory website on the Lassen project here
Chris White, a student on this project, has been working on a website
which is here.
Kurt Ingeman, a former student who worked on this project, wrote a
detailed introduction to the study of Life in Boiling Acid, a draft of which
can can be found here.
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