data source: noaa ccap watershed activity = nutrient load
TRANSCRIPT
Linking watershed activities to nearshore ecosystem processes: a case study of Elkhorn Slough
Brent Hughes
University of California Santa Cruz
Data source: NOAA CCAP
Watershed activity = nutrient load
Lettuce…lots of lettuce
Lettuce Row Crops
A dumptruck of NO3/day
Sea Lettuce (Ulva spp.)
Ulva production = 40 African Elephants/year
High Variability in Eutrophication Expression
Hughes et al. (2011) MEPS
Hughes et al. (2011) MEPS
Tidal range explains patterns in eutrophication
Hughes et al. (2011) MEPS
Tidal range explains patterns in hypoxia
What are the ecological effects of all this eutrophication?
Photo: Daniela Maldini
Tidal range explains benthic invertebrate diversity
from Oliver et al. 2009
Watershed activity = nutrient load = ecological effects
From: Valiela et al 1997 L&O
Watershed activity = nutrient load = ecological effects
From: Valiela et al 1997 L&O
Tomales Bay
Watershed activity = nutrient load = ecological effects
From: Valiela et al 1997 L&O
Tomales Bay
Elkhorn Slough
Tidal height determines winners and losers
Intro Background Nutrients Eutrophication Ecology Summary
From: Broenkow & Breaker 2005
Increase in flushing potential
Intro Background Nutrients Eutrophication Ecology Summary
From: Broenkow & Breaker 2005
Flushing explains eelgrass distribution
Conclusions• Watershed activity strongly influences nutrient dynamics in
Elkhorn Slough.• Intense nutrient loading has led to eutrophication of the estuary.• Tidal range has a strong influence on the expression of
eutrophication in the estuary.• Seagrass only persists in the absence of macroalgal mats.• Fish appear to be driven by eutrophication effects and
environmental conditions (i.e. Hypoxia).
AcknowledgementsAdvisors:
Kerstin Wasson (ESNERR & UC Santa Cruz)
Pete Raimondi (UC Santa Cruz)
Susan Williams (UC Davis)
Raphe Kudela (UC Santa Cruz)
Mark Carr (UC Santa Cruz)
Collaborators:
John Haskins (ESNERR)
Ken Johnson (MBARI)
Monique Fountain (ESNERR)
Aaron Carlisle (Hopkins)
Sarah Newkirk (TNC)
Beth Watson (EPA)
Kamille Hammerstrom (MLML)
Nora Grant (MLML)
Sean Abby (UC Santa Cruz)
Christine Manuck (USDA)
Gregor Cailliet (MLML)
Ron Eby (ESNERR)
Rikke Kvist Preisler (ESNERR)
Bryan Largay (ESNERR)
Gui Lessa (Universidade Federal da Bahia, Brasil)Steve Litvin (Hopkins)Miguel Rodriguez (Hartnell College)
Emily Matthews (UC Santa Cruz)
Shirley Murphy (ESNERR)
Sara Tanner (MLML)
Mark Silberstein (Elkhorn Slough Foundation)
AcknowledgementsFunding:
NOAA/NERR
The Nature Conservancy
UCSC EEB Department
Myers Oceanographic and Marine Biology Trust
Friends of Long Marine Lab
Community Foundation for Monterey
County/PG&E Non-Point Source
Pollution Grant (Grant # 20060387) Elkhorn Slough Foundation
Monterey County Water Resources Agency