Citation:
GLAHN, J. F., M. E. TOBIN, AND B. F. BLACKWELL,
editors. 2000. A science-based initiative to manage double-crested
cormorant damage to southern aquaculture. USDA Animal
and Plant Health Inspection Service, Wildlife Services
National Wildlife Research Center, Fort Collins, CO, APHIS
11-55-010.
Recommendations
Considering the status of cormorant depredation
problems and the limitations of current methods to alleviate
these conflicts, we make the following recommendations
concerning research needs and management actions.
The following initiatives are listed in chronological
order by completion date with the goal of implementing
definitive solutions to cormorant depredation problems
in the next 5 years. The time lines for achieving these
initiatives are presented in the subsequent table. Cormorant
Initiatives
Initiative 1 - Clarify the impact and
economic threshold of cormorant predation on catfish production
by December 2000.
- Complete QA-634 to determine actual catfish production
losses due to cormorant predation by December 2000.
- In consultation with agricultural economists, define
the economic threshold for cormorant predation on catfish
ponds by December 2000.
Initiative 2 - Assess the need to expand
the cormorant depredation order by June 2002.
- Expand areas of coverage and continue to monitor wintering
cormorant populations in Alabama, Arkansas, Louisiana,
and Mississippi.
- Develop feasible monitoring techniques and continue
to monitor breeding populations in Alabama, Arkansas,
Louisiana, and Mississippi.
- Through questionnaire surveys, monitor the take of
cormorants under the cormorant depredation order through
May 2002.
- Based on increasing breeding and wintering populations
and stable take under the cormorant depredation order,
petition the USDI-FWS to expand the cormorant depredation
order to include shooting in winter roosts and southern
breeding colonies.
Initiative 3 - Develop by October 2002
a goal-oriented population model to examine measures needed
to reduce cormorant flyway populations.
- Complete a study defining the demographics of wintering
cormorant populations by July 2002.
- Complete studies defining the demographics of Great
Lakes breeding cormorant populations by October 2002
- Develop a cormorant population model by October 2002
Initiative 4 - Determine flyway movements
of cormorants along the Mississippi Flyway by April 2002.
- Complete analysis of recent cormorant banding data
by July 2000.
- Complete a satellite telemetry study by April 2002
to define where and when flyway population management
can be best implemented.
Initiative 5 - Evaluate by September
2003 all localized control options for managing cormorant
depredations to southern aquaculture.
- Using information on flyway movements and the cormorant
population model determine by October 2002 the feasibility
of managing cormorant populations under an expanded
cormorant depredation order.
- Complete by September 2003 research to assess the
utility of non-lethal control strategies to reduce cormorant
predation to southern aquaculture.
Initiative 6 - Develop and implement
by April 2004 an integrated management plan for reducing
cormorant damage to southern aquaculture.
- In cooperation with the U.S. Fish and Wildlife Service,
the Canadian Wildlife Service, State wildlife agencies,
aquaculture interests, sport and commercial fisheries
representatives, and other interested parties, set local
and flyway population goals. In cooperation with the
same entities and using information obtained from strategies
1-5, develop by January 2004 an integrated management
plan for reducing double-crested cormorant conflicts.
- Implement the integrated cormorant management plan
by April 2004, including both localized and flyway management
for reducing cormorant damage to southern aquaculture.
Cormorant Initiatives
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Initiative 1 - Clarify the impact of FY 2000 FY 2001
FY 2002 FY 2003 FY 2004 Who cormorants on actual catfish
production should losses by December 2000. FY2000 FY2001
FY2002 FY2003 FY2004 Who Should do it.
Task A - Clarify actual production losses. NWRC
Task B - Determine economic thresholds of predation. NWRC
Initiative 2 - Assess the need to expand
the cormorant depredation order by June 2002.
Task A - Monitor wintering cormorant populations. WS
Task B - Monitor breeding cormorant populations. WS
Task C - Monitor take under depredation order. FWS
Task D - Petition to expand depredation order. WS
Initiative 3 - Develop a flyway population
model by October 2002.
Task A - Complete study of wintering demographics. NWRC
Task B - Complete study of breeding demographics. NWRC/FWS
Task C - Develop Cormorant population model. NWRC/FWS
Initiative 4 - Study cormorant flyway
movements
Task A - Complete analysis of cormorant banding data.
NWRC
Task B - Complete satellite telemetry study. NWRC
Initiative 5 - Evaluate all localized
control options for managing depredations.
Task A - Determine feasibility of managing cormorant
populations under expanded depredation order. NWRC/WS
Task B - Complete research on non-lethal options. NWRC
Initiative 6 - Develop and implement
an integrated cormorant management plan
Task A - Set population goals and develop an integrated
cormorant management plan. WS/FWS
Task B - Implement the integrated cormorant management
plan. WS & Others References Cited
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