USAMLR Datasets - PowerPoint PPT Presentation

Title: USAMLR Datasets


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US-AMLR Datasets
Pinniped research Mike Goebel
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CCAMLR Ecosystem Monitoring Program
CEMP was established in 1984 in response to a
developing krill fishery to

• detect and record significant changes in
  critical components of the marine ecosystem
• distinguish between changes due to harvesting of
  commercial species and changes due to
  environmental variability, both physical and
  biological.

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Pinniped species studied by US-AMLR

• Fur seal
• Elephant seal
• Weddells
• Leopards

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Predator performance Fur seals

• Summer (Local/Regional scale)
• Foraging success (4 indices, inc. trip
  duration)
• Trophic links food web diet studies (5)
• Reproductive success (4, inc. pup growth)

• Winter (Scotia Sea - broader geographic scale)
• Annual survival , natality (4 indices)
• Pup production (2 indices)
• Arrival condition timing of reproduction (2)

• Multi-year
• Demography - Population vital rates
• Age at first reproduction
• Net reproductive rate
• Mean generation time
• Intrinsic rate of growth

CEMP Indices
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Datasets collected Pinnipeds

• Data sets - Annual (1997/98 Present)
• DEMOGRAPHY - Mark-resight tag database
• Adult females tagged 12-15 (3 Cape-wide)
• Known-age 94
• Pregnancy and survival rates
• 500 pups tagged annually (7 of pup
  production)
• ECOLOGY
• TDR deployments (Dec-Feb)
• PTT/GPS deployments (Dec, Jan, Feb)
• Trip duration (CEMP)
• Pup growth (CEMP)
• TROPHIC LINKS (Scats, Fatty acids, Stable
  isotopes)

• OTHER PINNIPEDS
• Mark resight data leopards elephant seals
• Weaning mass elephant seals

Data sets - Periodic ECOLOGY Regional
surveys (SSMUs) (1986, 1991, 1995, 2001,
2006) OCEANOGRAPHY - large seals as samplers
CTD (2005-2009)
In collaboration with Chile
In collaboration with UCSC (NSF funded)
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Fur seal population vital rates

• Age-specific mortality
• Net reproductive rate
• Mean generation time
• Intrinsic rate of growth
• Age at 1st reproduction (AFR)

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Fur seal year class success 1982-2006
Recruitment and/or survival are variable
.that characteristic has not changed over three
decades
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Krill demographics fur seal performance
Krill length in fur seal diet
Krill maturity sex ratio
Fur seal trip duration

• Trip durations are shortest when
• Krill length is gt47mm
• Low proportion of juvenile krill
• High proportion of female krill

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Fur seal performance
Assessing overall fur seal performance an
ordination approach using 17 indices

• Fur seal performance was best 2000-2002 2006
  when
• Krill length was gt47mm
• Low proportion of juvenile krill
• High proportion of female krill

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Top-down impact on fur seal populations
28-50 of all fur seal pups consumed by mid-Feb
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Fur seal phenology Climate change effects?
Trends in arrival and parturition for female fur
seals
Arrival and date of birth are becoming earlier.
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Uniqueness of US-AMLR pinniped datasets

• Number of indices, length of time series, having
  a large known age population, and a large
  mark-resight database

• Demography vital rates for an Otariid

• Data are collected simultaneously with offshore
  data

• Leopard seal data

• Data sets are collected in a rapidly changing
  environment

• Colonizing events