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Status of the invasive alga Undaria pinnatifidain Monterey Harbor
Steve I. Lonhart
SIMoNSanctuary Integrated Monitoring Network
www.mbnms-simon.org
Collaborators• Elkhorn Slough National Estuarine Research Reserve
– Kerstin Wasson
• University of California Santa Cruz– Mark Carr, Craig Syms, Rich Walsh and Michelle Fuller
• Moss Landing Marine Laboratories– Michael Graham and Heather Kerkering
• California Department of Fish and Game– Bill Paznokas, Tim Olivas, David Osorio
• Monterey Harbor Master’s Office– Scott Pryor and Steve Scheiblauer
• City of Monterey Volunteer Services– Julie Dillemuth
Monterey Harbor Aug 2001
Santa Barbara HarborApril 2001
Channel Is. H.,Port HuenemeJune-Nov 2000
Santa Catalina Is.June 2001
LA and LB harbors,March-May2000
Spread of Undaria in CaliforniaFrom: Silva et al. (2002) in Biological Invasions
Using a framework for the control of marine invaders(From Bax et al. [2001] in Conservation Biology)
Step 1. Establish the nature and magnitude of the problemStep 2. Set clear objectivesStep 3. Consider full range of alternativesStep 4. Determine risks of control methodStep 5. Reduce riskStep 6. Assess cost-benefit of controlStep 7. Monitor and evaluate the program
Phenology of Undaria
• Japan: sporophytes begin rapid growth in winter, mature in late spring, die in summer
• France: two or more generations, spores released most of the year
• Monterey: tending towards overlapping cohorts
Oct and Nov 2002: stratified random sampling of floating docks
Undaria removed from Dec 02 to Feb 03
0
100
200
300
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500
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<10 11-20 21-30 31-40 41-50 51-60 61-70 71-80
Size (cm)
Number removed
N=1282Mean=16.7 cmVar=174.25
Undaria removed from Apr to Oct 03
0
50
100
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<10 11-20 21-30 31-40 41-50 51-60 61-70 71-80 81-90 91-100 101-110
111-120
>120
Size (cm)
Number removed
N=1111Mean=36.1 cmVar=1185.6
0
100
200
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800
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1000
Dec Jan Feb Apr May Jun Sep Oct
Number
Total
Damaged
Sporophyll
Mature
Undaria removed December 2002 - October 2003
What have we learned thus far?
• Eradication in Monterey Harbor is very unlikely• Undaria is not found on
– some shaded structures– pilings with heavy native algal cover
• Pugettia producta is the most common grazer• Sporophyte growth is variable in space and time• Undaria can recruit in fall• Boat and skiff hulls are fouled
• Coordination among agencies requires patience– Have MOUs in place for future invasions
What will we do next?
• Study survival of detached, pre-reproductive thalli• Look at effects of shading on recruitment, growth• Expand surveys beyond the harbor• Test Pugettia feeding preferences
Funding: none.Many thanks to the volunteers
from the City of Monterey
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