1) Microbial communities in the Fraser River vary seasonally and correlate with environmental factors like temperature, turbidity, ammonia, and silica. Certain bacteria like Sphingobacteria and Flavobacteria indicate seasonal changes and are more abundant in summer months. 2) The document analyzes samples from the Fraser River and its tributaries to understand the link between microbial diversity, river geochemistry, and transported particles. Economic activities in the Fraser River Basin include forestry, fishing, agriculture, and more. 3) Analysis found the most abundant bacteria phyla responded to changes in temperature, ammonia, turbidity, and silica. Sphingobacteria were more abundant in summer months compared to Flavobacteria

1. Seasonal Variation of the Geochemistry and the Effects on the
Composition in Microbial Communities Attached to Fraser River
Suspended SedimentsMichelle Bennett*a,b
, Audrey Eppa,b
Rosalie Luymesa,b
, Bernhard Peucker-Ehrenbrinka,b
, Marco Coolena
, Britta M. Vossa
, Sharon Gilliesb
, Steve Marshb
a
Woods Hole Oceanographic Institution, Woods Hole, MA, USA
b
University of the Fraser Valley, Abbotsford, BC, Canada
* Lead author. E-mail address: Michelle.Bennett@student.ufv.ca
INTRODUCTION
I. Microbial Communities
Microbial communities of the Fraser River are diverse and dynamic. The diversity of
patterns vary with environmental factors. The results show strong environmental
correlation with temperature, turbidity, ammonia and silica. Sphingobacteria and
Flavobacteria indicate seasonal changes during the summer months.
II. Fraser River Basin
The Fraser River is the largest watershed in BC, approximately draining 248,000km². The
importance of the study in the Fraser River Basin is to understand linkages between
microbial diversity and the biogeochemistry of Fraser River water and the particles it
transports. At this time, impacts of incident threat to human water security and biodiversity
is considered low compared to the rest of the world, but modelling has indicated the
encroachment of moderate threats to the lower East-West of the Fraser River Basin.
Economic activity includes forestry, fishing, mining, manufacturing, agriculture, tourism and
recreation. The river basin has also had forest loss due to logging, forest pine beetle and
land converted to agriculture.
III. River Samples
The time series samples in this study were taken from the main stem of the Fraser River in
Fort Langley. Time and space samples were taken from the upper tributaries of the Fraser
River at Lytton and the lower Fraser River at Fort Langley and New Westminster.
IV. Hydrology
An analysis of the Fraser River hydrological profile (Figure 3), indicates the
seasonal patterns in the flow. The graph demonstrates a dynamic hydrograph from
January 1, 2010 to November 1, 2013. The river flows at seasonal lows during the
winter often below 1000m³/s. The freshet occurs in mid May to mid June and the
magnitude shifts from year to year. The high flows are generated by the seasonal
snowmelt. A slight flow increase occurs in October to November when there is an
increase in annual rainfall. The flow model has an important relationship with the
other water variables. Water variables that were most significant to the
communities of microbes analyzed was temperature, turbidity, ammonia and
silica.
METADATA ANALYSIS
I. Field Measurements
• Observations, Water Temperature, Turbidity, Dissolved Oxygen, Conductivity, pH
and Oxidation Reduction Potential.
II. Lab Analysis
• Microbial Communities, Nutrients, Trace Metals, Organic Carbon, Inorganic
Carbon, Dissolved Nitrogen, Bank Sediment and Other Major Ions.
.
MAJOR FINDINGS
FURTHER DISCUSSION
I. Future Directions
We are currently working on further insights on variable relationships to microbial
communities and the comparison of microbial communities in spatial habitats.
II. Acknowledgements
This study was carried out at Woods Hole Oceanographic Institution with the support from
grant NSF-EAR 1226818 to BPE. We Thank Roy J. Carver Biotechnology Center (CBC) for
Illumina sequencing services, Marco Coolen for support with extraction and analysis, and
the many people at UFV that helped with sample collection. Thank-you to UFV for the
support with the Student Lead Research grant and Educational Enhancement Fund.
III. References
Morrison, J., Quick, M.C., Foreman, G.M., 2002. Climate change in the Fraser River
watershed: flow and temperature projections. Elsevier 263:230-244.
J. Morrison et al. / Journal of Hydrology
Bacteria Affected by Environmental Factors
PercentAbundanceofMostDominatePhylaGroup
Sample Identification
The 16s rDNA sequence analysis indicated the abundance of 39,000 species in time
series data at the Fort Langley location. The figure above is the relative abundance (%)
of the most abundant bacterial and archaeal phyla in the Fraser River time series
metadata analysis.
The hierarchic clustering of the time series samples is based on microbial community
structure using the hclust function in R. The longer the vertical branches the more
dissimilar the microbial populations (Figure 5).
Figure 6 shows the canonical
correspondence analysis (CCA) ordination
based on species abundances in particulate
organic matter from the Fraser River time
series (numbered) with abiotic
environmental factors represented by
vectors. All 39,027 OTUs (red crosses) were
included in the analysis. The data suggest
that many organisms responded most
dramatically to changes in temperature,
ammonia and/or turbidity and silica
content. Statistical proof of the analysis is
shown in Figure 7.
Permutation tests for CCA under reduced
model shown in Figure 7. The ANOVA test
was performed for all OTUs (total
prokaryotes) and for the most abundant
bacterial and archaeal phyla and classes.
The bacterial and archaeal groups that
showed a statistically significant response
(ANOVA, P<0.05) to the tested natural
environmental time series gradients are
marked in green. The CCA ordination of
the entire quantitative prokaryotic
community composition (“Total
prokaryotes”) is shown in Figure 7 for
comparison.
Figure 1
Figure 2
Fort Langley Location (Photo by Michelle Bennett)
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Percent abundance of
Sphingobacteria marked in green
and Flavobacteria marked in red
(Figure 8). Flavobacteria is an
obligate bacteria often associated
with sinking particles where they are
involved in the initial breakdown of
biopolymers. The trend shows
Sphingobacteria becoming more
abundant during the summer
months.
B11A-0360
DISCHARGE(m³/s)