Lake Michigan’s Changing Nearshore: Understanding Type E Avian Botulism Outbreaks at Sleeping Bear Dunes National Lakeshore
Emily Tyner1,2, Brenda Moraska Lafrancois1, Harvey Bootsma2, Chris Otto2
1. UWM-School of Freshwater Sciences
2. National Park Service-Sleeping Bear Dunes National Lakeshore
GLRI Project #91Predict and prevent avian botulism outbreaks
• Beach monitoring for avian mortality
• Investigate toxin pathways
• Confirm links between botulism outbreaks and environmental conditions
• Targeted benthic habitat mapping
Beach Monitoring3 study sites monitored every 7-10 days , June-November
Door County
NWHC & Wisconsin DNR (2010), AMBLE Volunteers (2011)
Eastern Upper Peninsula
Common Coast biologist
w/ support from Seney NWR
Sleeping Bear Dunes NL
Volunteers & park staffPhoto credit: Sharon Cobb
Jenny Chipault, USGS-NWHC (2012)
Clostridium cells and spores (<1 µm size)
Where are some likely micro-habitats for C. botulinum?
At the base of mussel aggregates where pseudofecesand organic substrates collect
Under mats of sloughed Cladophora
Cladophora with marl deposits
At the base of mussel/Cladophoraaggregates
Sediments below any of these materials
Sheridan Haack, USGS Michigan Water Science Center, 2012
1. Water temperature + hydrodynamics
Botulism outbreaks and environmental conditions
2. Mussel, round goby, invertebrate counts
Benthic Habitat Mapping
• Highlights depositional areas
– Cladophora Graveyard
– Sleeping Bear Point
• Anoxic Cladophora mats documented in these areas
Sleeping Bear Point, 65 ft, Oct 2011
Acknowledgements
UWM-Bootsma LabHarvey BootsmaBen TurschakErin WilcoxLisa DeGuire
National Park ServiceBrenda Moraska LafrancoisAlicia HighamDan RayChirs OttoSue JenningsEmily KobernikEmma KellyChris JohnsonDave Schroeder
UWM, NPS, GLSC
currents
bathymetry
growing conditions
Cladophora sloughs and
settles
Sediment,C. botulinum,invertebrates
Cladophora decays
Sediment,C. botulinum,invertebrates
currents,disturbance (D.O.)
temp
Sediment,C. botulinum,invertebrates
Nearshoreand/or offshore
food webstoxin
intoxicated invertebrates,
particles
Re-suspensionDeposition DepositionDecay
Birds
Fish
toxin
toxin
storms, seiche, upwelling, turnover
Cladophoragrows
Growth
seasonal migration; feeding habits
BODM Distribution of anoxic areas
BGM
Air temperature Wind Sloughed Cladophora C. botulinum distribution
distribution
TPM
Water temperature Current Cladophora settling Toxin distribution
(velocity, direction)
CGM CDM
Nutrients Cladophora sloughing Carcass distribution
(P, N, O2)
Light Hydrodynamic model Cladophora growth
Bathymetry Cladophora maps
(Depth, lake level)
???
Loons
Dreissenid nutrient inputs
Fish
Pathogens
Lisa Fogarty and Riley
Cladophora senesces
Cladophora Biomass Peaks
epiphytes ↑invertebrates↑
Dreissena (now)
Point Sources (historically)
toxin
high temps competition
DOM ↑Temps Hi
Prod:Resp ↓DO ↓
epiphytesinvertebrates
mussels
Birds
storms, currents
epiphyteburden
Cladophora sloughs & drifts
epiphytesinvertebrates
mussels
toxin
Cladophora re-growth
storms,seiche
Cladophora deposits
[ON SHORE]
epiphytesinvertebrates
mussels
toxin
Cladophora deposits [IN LAKE]
epiphytesinvertebrates
mussels
toxin
lowlake levels
light
substrate nutrients
temp
invasions
migration
feeding habits
Burial,unburial
Burial,unburial
Fish
animated version
Jul-DecJun-Jul
(Oct)Jul-Dec
Jun(Sep-Oct)NPS