Speaker:
Jeremy VendittiProfessor - School of Environmental Science\, Simon Fraser University
Talk Title: Salmon vs the landslide: The rockslide th at blocked the Fraser River
Abstract:
Salmon are iconic animals o
n the west coast of North America\, a critical element of Indigenous cultur
e and an important commercial and recreational fishery. Salmon are born an
d reared in rivers\, migrate to the ocean for 1-3 years\, then return to th
eir natal spawning grounds. The Fraser River hosts one of the largest wild
salmon runs in the world and is the most productive salmon-bearing watersh
ed in Canada. Successful reproduction requires that salmon pass a gauntlet
of fisherman in the ocean and a 375-km long bedrock canyon that is suscept
ible to blockage by landslides. On November 1st\, 2018 the Big Bar Landslide temporarily blocked
the Fraser River\, initiating the largest and most expensive emergency riv
er restoration projects in the history of Canada. Approximately 8.9×104m3 of rock failed into the Fraser River\, creati
ng a 7.5-m high overfall that is similar to a waterfall\, but without freef
alling water into a plunge pool. Upstream migration success for salmon popu
lations exposed to the highest flows in 2019 was <1%\, gradually improving
to 80% for populations exposed to lower flows. Blasting the canyon and sli
de debris in 2020 increased the salmon passage threshold discharge to a lev
el that minimized the potential risk of extirpation for high flow salmon po
pulations in the Northern Fraser Basin. I will report on a research progra
m that used geospatial data\, observations of flow dynamics\, and radio tel
emetry to 1) find the next landslide that could block the Fraser River\, 2)
find other hydraulic barriers to salmon migration\, and 3) assess the pote
ntial impact of another landslide on salmon abundance and diversity.
Speaker bio:
Jeremy Venditti is a Professor of Environmental Science at Simon
Fraser University (SFU). He is the founding director of the School of Envir
onmental Sciences and an Associate Member of the Earth Sciences and Geograp
hy Departments. He holds a B.Sc. from the University of Guelph\, a M.Sc. fr
om the University of Southern California and a Ph.D. from the University of
British Columbia (2003). From 2004-2006 he was a post-doctoral fellow at t
he University of California at Berkeley. He was a Visiting Associate in 201
4 and a Visiting Professor in 2024 at Caltech.
From 2021-2024 he led a team of researchers funded by the British Columbia Salmon Restoration and Innovation Fund (BCSR IF) to examine the impacts of Big Bar Landslide on salmon migration\, popul ations\, and genetic selection. His ongoing work focuses on 1) Understandin g flow dynamics in bedrock canyons\, 2) The distribution of hydraulic barri ers to salmon migration in rivers\, and 3) The risk posed by landslides and high flow events to salmon abundance and diversity in the Fraser River.
[buttons][button link_text="Zoom link" link_url="https://ubc.zo om.us/j/66932229867?pwd=jBmaKW852xYSfbF8Wt7VXQXb4mSdBd.1"][/buttons]
CATEGORIES:Featured Events URL;VALUE=URI:https://geog.ubc.ca/events/event/geography-colloquium-series- jeremy-venditti/ ATTACH;FMTTYPE=image/png:https://geog.cms.arts.ubc.ca/wp-content/uploads/sites/26/2024/12/GEOG-Colloquium-Jeremy-Venditti-Feb-25th-2025-X.png END:VEVENT BEGIN:VTIMEZONE TZID:America/Vancouver BEGIN:STANDARD TZOFFSETFROM:-0700 TZOFFSETTO:-0800 DTSTART:20241103T090000 TZNAME:PST END:STANDARD END:VTIMEZONE END:VCALENDAR