Transcript Human-mediated and natural dispersal of invasive species

Human-mediated and natural
dispersal of invasive species:
implications for watershedscale management practices
Thomas Horvath
Biology Department
State University New York
College at Oneonta
Linkages:
Lentic-lotic links
Human-invasive species links
Weekly World News, August 1993
“Non-native species cause
$123 to 137 billion in damage
annually – more than twice the
annual economic damage
caused by all natural disasters
in the US.”
D. Pimentel
24 Jan, 1999 AAAS
%Species Affected by Cause (n=1,880)
100
80
60
40
20
Habitat
Degradation/
Loss
Exotic/
Invasive
Species
Pollution
Overexploitation
0
Disease
Source: Precious Heritage:
The Status of Biodiversity
in the United States
© The Nature Conservancy
and NatureServe
“Invasive species and their
environmental damage are the
most irreversible form of
pollution.”
David Lodge
Chair, National Invasive Species
Advisory Committee
Dreissena polymorpha (Pallas)
Economic Impacts
Ecological Impacts
Direct impact on native Bivalves
Freshwater Mussel Diversity
Family Unionidae
Proportion of Freshwater Dependent
U.S. Species at Risk
Freshwater
Mussels
Crayfishes
Amphibians
Freshwater
Fishes
Flowering
Plants
Conifers
Ferns
Tiger Beetles
Dragonflies/
Damselflies
Reptiles
Butterflies/
Skippers
Mammals
Vulnerable
Imperiled
Critically Imperiled
Presumably/
Possibly Extinct
Birds
0% 10%
20% 30% 40%
50% 60% 70%
Source: Precious Heritage:
The Status of Biodiversity
in the United States
© The Nature Conservancy
and NatureServe
Dispersal Mechanisms
Lentic – Lotic
Linkages
Veliger
Adult mussel
Passive Dispersal
Veligers L-1
Eaton Brook
5
16
14
12
10
8
6
4
2
0
2003
2004
4
3
2
1
0
2
4
6
8
0
0
2
Distance from Lake-Outlet (km)
4
6
8
Oaks Creek
2003
Veligers L-1
6
4
4
2
2
0
0
0
5
10
15
20
25
2004
6
0
5
Distance from Lake-Outlet (km)
10
15
20
25
Veliger Flux (2003)
1800
1600
1400
1200
1000
800
600
400
200
0
Veligers (millions day-1)
120
Eaton Brook
100
80
60
40
20
0
0
2
4
6
8
Oaks Creek
0
Distance from Lake-Outlet (km)
5
10
15
20
25
Linkages due to Human Behaviors
Boater Survey Results
Eaton Brook Reservoir
• Estimated 1635 recreational visits to EBR
• 98% of boaters have heard of zebra mussels
• 32% of boaters don’t know how to prevent
the spread of zebra mussels
224 survey points
126 interviews
Boater Survey Results
Eaton Brook Reservoir
• 55 boaters had used their boat in a nearby
ZM lake within past week
• 20% of all boaters were moving to another
non-ZM lake within a week
Boater Survey Results
Eaton Brook Reservoir
• 14% of boaters had aquatic plants on their
boat after as they were leaving
• 6% of boaters had live zebra mussels on their
boats
Boater Survey Results
Eaton Brook Reservoir
• 14% of boaters had aquatic plants on their
boat after as they were leaving
• 6% of boaters had zebra mussels on their
boats
1635 boat trips x 6% w/ zm
≈ 100 boaters transporting live
zebra mussels in 2004
What Can We Do?
Zebra Mussels (Dreissena polymorpha) in the
Chesapeake Bay Watershed:
A Regional Management Plan
Chesapeake
Bay Program
•
Goals
1. Stop the further spread of zebra mussels by
identifying strategies and partnerships necessary
to control the spread of mussels
2. Eradicate zebra mussel colonies in the Chesapeake
Bay watershed where possible
Invasive species management
plans recommends:
•
•
•
•
•
public outreach programs
monitoring programs
rapid response strategies
possible eradication methods
actions and funding needs to implement each of
the recommendations
Species entrained in transport pathway
Survives transport & introduction
Establishment
S
p
r
e
a
d
Preventive
Fails in Mgt
transport
Actions
Fails in
establishment
Noninvasive
Invasive
Kolar & Lodge 2001
Otsego Lake
Cooperstown, NY
Ending Thoughts
• Lakes serve as sources for further invasions
• Models suggest the “stitch in time” approach
makes sense
Policy makers should be informed
of the benefits of prevention
programs from the standpoint of
both reducing species invasions
other than the targeted species, as
well as the economic benefits
associated with avoiding potential
future direct and indirect costs of
unchecked invasion, control, or
elimination.
Horvath. 2008. Economically
viable strategy for prevention of
invasive species introduction: Case
study of Otsego Lake, New York.
Invasive Species 3(1): 3-9.
Thank You
[email protected]
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