quagga/zebra mussel life history
TRANSCRIPT
Quagga/Zebra Mussel Life History
Robert F. McMahon Professor Emeritus
Department of Biology The University of Texas at Arlington
The University of Texas at Arlington
Center for Biological Macrofouling Research
Zebra Mussels in Lake Texoma, TX/OK
Outline
• Invasive Biology and Impacts of Zebra and
Quagga Mussels
• Invasion of North American Inland Waters
• Filter Feeding and Ecological Impacts
• Reproduction and Population Dynamics
• Requirements for a successful invasion
• Conclusions
Dreissenid Mussel Invasion of North American Inland Waters
Zebra and Quagga Mussels • Originally endemic to Europe
• Introduced to North America in ~ 1986
• Zebra mussels found in Lake St. Clair and western Lake Erie in 1989 • Quagga mussels also introduced in 1986 but not identified until 1991
• Rapidly spread throughout major US and Canadian drainage systems east of the Rocky mountains • Zebra Mussels: Great Lakes drainage, Mississippi River and eastern
tributaries, lower Missouri River, Arkansas River, isolated water bodies
• Quagga Mussels: Great Lakes drainage, upper Mississippi and lower Ohio Rivers, lower Colorado River, water bodies in Colorado, Arizona, southern California
• Rapid dispersal through navigable waterways on commercial vessels • Dispersed more slowly to isolated water bodies (i.e., overland transport)
• Quagga mussels found in Lake Mead (2007), soon after in the lower Colorado River, and reservoir lakes in southern California, Arizona
• Zebra Mussels found in San Justo Reservoir Central California (2008)
• Most costly macrofouling and ecological pests ever introduced to North American freshwaters
Zebra Mussel Dreissena polymorpha
Quagga Mussel Dreissena rostriformis bugensis
Dreissenid Shell Morphology
1988
Zebra Mussel Invasion of the US
1990
Zebra Mussel Invasion of the US
1992
Zebra Mussel Invasion of the US
1994
Zebra Mussel Invasion of the US
1996
Zebra Mussel Invasion of the US
1998
Zebra Mussel Invasion of the US
2000
Zebra Mussel Invasion of the US
2002
Zebra Mussel Invasion of the US
2004
Zebra Mussel Invasion of the US
2005
Zebra Mussel Invasion of the US
2008
Zebra Mussel Invasion of the US
2009
Present Quagga Mussel Distribution in the United States
Byssal Threads
Byssal Attachment
Cirri
Frontal Cilia
Zebra Mussel
Filter Feeding
and Its
Ecological
Impacts
Filter Feeding • Zebra and quagga mussels both
efficiently filter bacterioplankton (< 1 µm)
• Large adults may filter up to 1 L / hr
•Average ≈ 1.5 L / Day
• 150,000 L / Day at a density of 100,000 mussels / m2
• Results in rapid water clarification
• Removes phytoplankton and bacteria negatively impacting energy flow through food webs
• Promotes toxic blue-green algae blooms
•Quagga mussels are more efficient at filtering bacteria
• Can leads to eventual replacement of zebra mussels by quagga mussels
Average Secchi Disk an Chlorophyll a Concentration, Seneca Lake , NY
Maximum Depth of Submerged Macrophytes
in Oneida Lake, NY
Area of Submerged Macrophyte Cover,
Oneida Lake, NY
Filter feeding Impacts
Zhu. et al., 2006 Zhu. et al., 2006
Aquatic macrophyte growth in Lake St. Clair, MI, stimulated by zebra
mussels clarifying the water column
Dreissenid Mussel Impacts on Aquatic
Ecosystems
Lake Erie Food Web
Pelagic Benthic Macrophytes
Zebra/Quagga Mussel
Reproduction and
Population Dynamics
Dreissenid Life Cycle • Separate sexes - external fertilization
• Fecundity as high as 1,000,000 eggs per adult female per year
• Trochophore larva (6-20 Hours)
• No shell (≥ 40 µm)
• Early Veliger larva (3-4 Days) • D-shaped shell (80-100 µm)
• Late veliger larva (1-2 weeks) • Umbonal shell (100-250 µm)
• Pediveliger larva (2-3 weeks)
• Develops foot – settles, crawls to attachment site (200-400 µm)
• Plantigrade (3-4 weeks)
• Byssal attachment – transforms to mussel shape (250-500 µm)
• Juvenile (3-5 Weeks) • Mussel-shaped shell (>400 µm)
• Spawning occurs at low levels > 10°C
• Spawning maximized at > 18-28°C
• Settle in three to five weeks
D-shaped Veliger
Umbonal Veliger
Plantigrade
Umbonal Veliger
Pediveliger
Plantigrade Juvenile
Veligers
Zebra mussel veliger larvae from
Lake Texoma, Texas/Oklahoma
Newly Settled Juvenile Zebra Mussels, Lake Texoma, TX/OK
Dreissenid Population Dynamics
•Maximum age = 3-5 years depending on population
•Maximum adult size = 25 – 40 mm dependent on population
•Growth rate declines with increasing adult size
• Survival rate is low across year classes
•Adult growth rates and population density dependent on temperature and phytoplankton/bacterioplankton food density
•High fecundity leads to development of massive populations within 3-5 years after initial introduction
Zebra Mussel Growth and Longevity
in European Water Bodies
Zebra/Quagga Mussel
Requirements for
Successful Invasion
Water Quality Factors Affecting Dreissenid Mussel
Distribution and Invasion
• pH: Inhabit waters of pH > 7.4 • Attain highest densities at pH > 8.0
• Salinity: • Do not spawn or successfully fertilize above 7 ppt (21% SW)
• Larvae do not develop at > 8 ppt (24% SW)
• Juveniles and adults do not survive > 5 ppt (14% SW)
• Turbidity and Suspended Solids: • Thrive in lower Ohio and Lower Mississippi Rivers at > 80 NTU units
• Turbidity unlikely to be a factor in limiting distribution
• Organic Enrichment: • Does not generally limit distribution except when associated with
hypoxic conditions - will accelerate growth
• Phosphate Concentration: Found as low as 0.001 mg/L
• Nitrate Concentration: Not found below 0.009 mg/L
• Calcium Ion Concentration: Not found below 10-12 mg Ca/L
• Total Hardness: Not found below 25 mg/L Ca
• Alkalinity: Not found below 20 mg/L Ca
• Potassium Ion:
• Intolerant of waters with natural potassium concentrations > 30 mg
K1+/L (portions of upper Missouri River drainage basin)
• Flooding and Water Level Variation:
• Can have limited success in rivers prone to extensive flooding and
lakes with large annual level fluctuations (exception is Lake
Pleasant, Arizona)
• Large stable rivers and lakes with reduced level fluctuations are
most prone to invasion
• River populations are sustained by settlement of larvae carried downstream from mussel populations in upstream impoundments
• Pollution:
• Generally as tolerant of industrial and municipal water pollution as
are native unionid and Asian clams
• Will not invade waters made chronically hypoxic by receipt of
organic pollutants
Water Quality Factors Affecting Dreissenid Mussel
Distribution and Invasion (Continued)
1°C Mean Maximum Air Temperature Isotherms (1961-1990)
Source: Spatial Climate Analysis Service, Oregon State University
Confirmed zebra mussel populations
33°C
Confirmed western
quagga mussel populations
34°C
35°C
35°C
32°C
Windfield City Lake Lake Oologah
Lake Texoma
Temperature Tolerance
Predicted Zebra Mussel Distribution Based on Average Maximal and minimal
Monthly Surface Water Temperatures
• Generally agreed long-term incipient upper thermal limit of zebra mussels was 30°C and 28°C for quagga mussels
• Generally agreed temperature for initiation of spawning was 16-18°C • These temperature limits were used predict potential zebra mussel distribution in North
America based on maximum summer surface water temperatures – similar for quagga mussels
• Recent successful establishment of zebra mussels in warm waters of Texas and quagga mussels in the warm waters of the Lower Colorado, southern California and Arizona requires a re-examination of these assumptions
Zebra/Quagga Mussel Invasion of Southwestern Water Bodies
0 5 10 15 20 25 30
TEMPERATURE (°C)
0
50
100
150
200
250
300
350
400
LT50
100%
80%
60%
40%
20%0%
0 5 10 15 20 25 30
TEMPERATURE (°C)
0
100
200
300
400
500
600
700
800
LT100
80%
60%
40%
0%
100%
20%
Desiccation Tolerance in Zebra Musselsat Different Temperatures and Relative Humidities
Ho
urs
Su
rviv
ed
Ho
urs
Su
rviv
ed
Zebra Mussel Emersion Tolerance
• Summer emersion tolerance (<10-20 days)
• Temperature and humidity dependent
• Allows long distance overland transport
McMahon and Ussery
Trailered Boats as Zebra Mussel Dispersal Vectors in Southwest US
Britton and McMahon
100th Meridian
Boater Movement
in Western States
Database
Conclusions
• Zebra mussels in Oklahoma and Texas and quagga mussels in the lower Colorado
River, southern California and Arizona appear to evolved an increased thermal
tolerances which will allow them to invade the warm waters of the Southwestern US
• Could eventually lead to infestation of northwestern US water bodies
• Invasion risk assessments are required to determine the most at risk water bodies
• Analysis of boater movements/visitations
• Analysis of water body physical/chemical parameters
• pH, Ca2+ concentration, summer surface water temperatures
• Concentrate prevention efforts on at-risk water bodies
• Population genetics data suggest that introduction of large numbers of zebra or
quagga mussels are required to establish sustainable infestations
• Reducing the rate of mussel introduction could reduce potential for infestation
• Invasion risk assessments and monitoring for western water bodies
• Public and boater outreach/information/education programs
• Inspection and decontamination of boats and other submerged equipment
when leaving infested waters or entering un-infested waters
• Inspection and decontamination of large commercially hauled vessels
• HACCP plans/regulations developed to prevent mussel introduction on
construction/work sites in or near water bodies
• Development and enforcement of adequate rules, regulations and laws
• Coordination of prevention efforts among federal, state, and private entities
Thanks
For Your
Attention
Questions?