Environmental Toxicology - Quantifying contaminant impacts ...cfink/ES 10/finkelstein.pdf ·...
Transcript of Environmental Toxicology - Quantifying contaminant impacts ...cfink/ES 10/finkelstein.pdf ·...
Environmental Toxicology -
Quantifying contaminant impacts
& identifying solutions
ES 10 Spring 2016 Myra Finkelstein ([email protected])
Associate Adjunct Professor
Microbiology & Environmental Toxicology
What are the effects of environmental contamination on individuals and populations?
Classic toxicology:
Establish relationship: Dose Response
Dose
Re
sp
on
se
(ce
ll d
ea
th)
Contaminant effects in a wild species
(as opposed to in a dish of cells in a lab)
food
predation competition
survival
reproduction
Not easily defined!
Challenging to assess contaminant-induced effects in wild populations
Effects are typically really bad before we can detect them!
cell function
Most contaminant effects not overt
overt
Contaminant effects system
function
Egg shell thinning –
zero reproductive success
1947-1971: 110 tons of DDT
So. CA Bight
DDT DDE
biota
DDT banned
California Brown Pelicans
endangered species
DDE & Brown Pelicans
X
Smallest of North Pacific albatross
- wing span ~ 2 m
- weigh ~ 2.7 kg
Long-lived ~ 60 yrs, start breeding ~ 8yrs
Low reproduction – one chick per year
Naturally low adult mortality
Laysan albatross
(Phoebastria immutabilis)
Wide-ranging
- good indicators of
pelagic systems
Accessible for studying
- tied to land to breed
Finkelstein et al., Ecol. Apps. (2006)
Pelagic predator
Laysan albatross
1900’s: Feather harvesting reduced populations by >90%
Laysan albatross
~ 400,000 pairs
~ 70% of global population
•Former
military base
•U.S. Wildlife
Refuge
Study Site: Midway Atoll
*
Quantify impact
Extrapolate to populations
Identify solutions
?
Quantify impact
Extrapolate to populations
Identify solutions
?
Midway Atoll: 70% of breeders;
former military base
Lead contamination a problem? Highly toxic
– Nervous
– Blood
– Immune
– Renal
– Reproductive
Laysan chicks: High lead exposure
0
50
100
150
200
250
300
350
400
450
near buildings n=21
reference n=15
blo
od lea
d (
µg/d
L)
severe morbidity
clinical treatment
> 90% of chicks near bldgs. likely
lethally exposed to lead
Lead exposure causing lethal lead effects
droopwing
0
50
100
150
200
250
300
350
400
450
near buildings n=21
reference n=15
blo
od lea
d (
µg/d
L)
Quantify impact
Extrapolate to populations
Identify solutions
survival
reproduction lead
bycatch
Population Viability Analysis:
Mathematical models to predict likely future status of a
population
Vital rates:
- survivorship of individuals by age
- number of young per female
Key impacts:
- lead effects on chick survival:
7% (~10,000 chicks/year)
- bycatch effects on adult survival
1 to 3%
Translate individual impacts to populations with
Population Viability Analysis (PVA)
Laysan albatross populations declining
on Midway Atoll
440000
640000
840000
1040000
1240000
0 20 40 60 80 100
years into future
popula
tion s
ize
current conditions
Eliminating lead reduces population decline
440000
640000
840000
1040000
1240000
0 20 40 60 80 100
years into future
popula
tion s
ize
no lead deaths
current conditions
Need to reduce bycatch for stable growth
Finkelstein et al., Anim. Cons. (2010)
440000
640000
840000
1040000
1240000
0 20 40 60 80 100
years into future
popula
tion s
ize
no lead deaths
increase adult
survivorship by 1%
current conditions
(plastic?)
Plastic disposal from ships/offshore transport
Ingested by wildlife
Accumulation at
convergence zones
Quantify impact
Extrapolate to populations
Identify solutions
survival
reproduction lead
bycatch
Identify solutions for reducing lead-related
mortality:
1. Identify exposure source
2. Eliminate/reduce exposure
source
Source of lead exposure: Isotopic analysis
4 stable lead isotopes
Lead signatures in organism
reflect lead signatures in source
- Trace metal clean techniques
- Highly sensitive measurements
Concentrated nitric acid
1
10
100
1000
chicks near buildings
n=21
chicks reference
n=15
adults
n=10
- Diet-derived source – NO – adults low
- Widespread soil contamination – UNLIKELY– reference low
- Lead-based paint on buildings - POSSIBLE
lo
g b
loo
d le
ad
(µ
g/d
L)
Identify plausible source(s) of lead exposure
blood
0.80 0.82 0.84 0.86 0.88 0.90 0.92 2.02
2.04
2.06
2.08
2.10
2.12
2.14
2.16
207Pb/206Pb
20
8P
b/2
06P
b
Lead-based paint source of poisoning
paint
Finkelstein et al., ES&T (2003)
Chick 4
Chick 3
Chick 2 Chick 1
Increase adult survivorship: Reduce fisheries bycatch
• international regulations
• complex political/social issues
Solutions to increase population growth
Eliminate lead poisoning: ~190,000 more birds in
50 years Finkelstein et al., Anim. Cons. (2010)
Increase chick survivorship: Remediate lead paint
• technology exists
• straightforward
Published research: “Assessment of demographic risk factors and management priorities: impacts
on juveniles substantially affect population viability of a long-lived seabird”
Finkelstein et al., Animal Conservation, 2010 13: 148–156
Share research results to inform decisions
June 2010:
lead paint clean-up authorized
Paint clean-up will eliminate lead poisoning of
Laysan albatross chicks
North America’s largest bird
- wing span ~ 3 m
- weigh ~ 9 kg
Long-lived ~70 yrs, start breeding ~ 6yrs
Low reproduction – one chick per year
Naturally low adult mortality
California condor
(Gymnogyps californianus)
Effective scavengers!
California condor decline
Map courtesy of M. Johnson
data adapted from Snyder and Snyder (1989)
• ~600 birds end 1800’s
• 22 condors in 1982 End 1800’s
1982
California condor: One of world’s rarest birds
• 1980s - breeding program
• 1987 all condors in captivity
• 1992 first release of captive- reared birds
United States - Federal protection since 1970’s
IUCN - Critically Endangered since 1994
USFWS 2013
Pinnacles National Park
Ventana Wilderness
Bitter Creek
Vermillion Cliffs
Sierra de San Pedro Martir
Wild: - California, USA: 155
- Baja California, MX: 33
- Arizona, USA: 80
California condor
December 31st 2014
Total population: 435
(zoos & “wild”)
0
20
40
60
80
100
120
140
160
180
200
19
94
19
96
19
98
20
00
20
02
20
04
20
06
20
08
20
10
20
12
Wild population increase due to captive releases N
um
be
r o
f b
ird
s
Wild-
fledges
Dead or
removed
Captive-
reared
releases
More die than born = population not sustainable
• 1970’s: documentation condors
have high lead
• 1980’s: first lead-related condor
death identified
Quantify impact
Translate to populations
Identify solutions
?
Monitored on near daily basis • blood lead checked ~2x per year
• odd behavior – trapped to assess lead
• blood lead ≥45 µg/dL – clinical treatment
0
10
20
30
40
50
60
70
80
90
100
Year
1998 2000 2002 2004 2006 2008 2010 2012
Perc
ent
lead p
ois
oned
~20% of condors tested per year
need clinical treatment
~60% of wild birds lead poisoned
Finkelstein et al. 2012 n = 987 independent blood samples
Lead poisoning: # 1 mortality factor for
juvenile & adult free-flying condors
Rideout et al., J. Wildl. Dis. (2012)
Quantify impact
Extrapolate to populations
Identify solutions
survival
reproduction lead
Condor performance over past 20 yrs
• annual survivorship of individuals
• number of fledged young/female
Three scenarios - no future releases
• continued management for lead
• cessation of management for lead poisoning
• no lead deaths
Translate individual impacts to populations with
Population Viability Analysis (PVA)
0 5 10 15 20 0
20
40
60
80
100
120
140
Lead preventing condor recovery
lead
management
no lead
management
no lead deaths
Finkelstein et al., PNAS. (2012) years into future
# f
ree
-fly
ing b
irds in C
alif
orn
ia
lead
Quantify impact
Extrapolate to populations
Identify solutions
survival
reproduction
1. Identify exposure source
2. Eliminate/reduce exposure
source
Identify solutions for reducing lead-related
mortality:
Condors ingest spent lead ammunition
Finkelstein et al. (2012)
0.76
0.78
0.8
0.82
0.84
0.86
0.88
0.9
0.92
303 306 318 401 400 452
Condor ID
lea
d r
ati
o (
20
7P
b/2
06P
b)
blood lead item
Source of lead exposure:
Isotopic analysis
Ammunition principal
source of lead to condors
1. Reduce use of lead ammunition
2. Reduce reliance on lead-shot carcasses
Solutions to increase population growth
Reduce exposure to lead-based ammunition
On California beaches each year:
• ~100 cetaceans
• ~2,000 pinnipeds
Lead-shot carcasses - terrestrial
Condors on coast: Lower lead
poisoning risk
0
0.1
0.2
0.3
0.4
<50% 50-74% >=75%
% time on observed on coast (n=63 birds)
pro
bab
ility
lea
d p
ois
on
ed
(n
=5
23
blo
od
sa
mp
les)
Condor:
Top marine scavenger
Terrestrial
Pollution
(DDE)
grass
deer
condor
zooplankton
fish
marine mammals
Marine
phytoplankton
condor
www.gotmercury.org
0
500
1000
1500
2000
2500
3000
coastal n=22
inland n=8
DD
E p
lasm
a (
µg/d
L)
Coastal condors: Higher DDE
peregrine falcon
egg shell thinning
bald eagle egg shell thinning
prairie falcon egg shell thinning
Next steps: Quantify impacts of lead and DDE
0 5 10 15 20 0
20
40
60
80
100
120
140
lead
management
no lead
management
no lead deaths
years into future
Fre
e-f
lyin
g p
opula
tion s
ize in C
alif
orn
ia
DDE ?
Solutions to increase population growth
Reduce exposure to lead-based ammunition
DDE?
1. Reduce use of lead ammunition
2. Reduce reliance on lead-shot carcasses
Share research results to inform decisions
Oct. 2013: law to require non-lead ammunition for
hunting throughout entire state of California
Use of non-lead ammunition: Prevent lead poisoning of condors
and promote species recovery
Research supported by US Fish and Wildlife Service
National Park Service
Montrose Settlements Restoration Fund
Western National Parks Association
David H. Smith Postdoctoral Fellowship
Switzer Environmental Leadership Grant
Switzer Environmental Fellowship
EPA STAR Graduate Fellowship
ARCS Scholarship Collaborators Don Smith (UCSC), Dan Doak (CU-Boulder),
Vickie Bakker (MSU), Carolyn Kurle (UCSD),
David Anderson (WFU), Joseph Brandt
(USFWS), Joe Burnett (VWS), Don Croll
(UCSC), Daniel George (NPS), Roberto
Gwiazda (MBARI), Brad Keitt (IC), John
Klavitter (USFWS), Paul Sievert (UMass),
Bernie Tershy (UCSC), Gerald Winegrad (ABC)
Special thanks USFWS, Midway Atoll National
Wildlife Refuge, Rob Franks, Breck
Tyler, Thierry Work , Los Angeles
Zoo, Pinnacles National Pak,
Ventana Wildlife Society
Undergraduate/Graduate students Molly Church, Mary Goldman, Gayle
Kouklis, Zeka Kuspa, Lauren Lee,
Melinda Nakagawa, Mara Nydes
Photo credits Joe Burnett, Mike Clark, Gavin Emmons,
Daniel George, Bill Henry, Pinnacles
National Park, Graham Robertson, Don
Smith, Stuart Thorton, Breck Tyler