Notes

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Outline

1	Characteristics of Calanus finmarchicus dormancy patterns in the northwest Atlantic
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3	Data sources
4	Proxies for dormancy entry and exit Entry (Onset) Fifth copepodid (CV) half-max proxy Dormant when… CV proportion ≥ `x / 2 where `x = average max. CV proportion over all years Exit (Emergence) Emergence when… 1. Adult (CVI) proportion ≥ 0.1 2. Back-calculation from early copepodid appearance, using development time-temperature relationship
5	AG: Anticosti Gyre, NW Gulf of St. Lawrence
6	Possible dormancy cues Onset Photoperiod (Miller et al., 1991) Temperature (Niehoff & Hirche, 2005) Food availability (Hind et al., 2000) Lipid accumulation (hormonal link?) (Irigoien, 2004)
7	Onset of dormancy ANOVA
8	Climatological temperature at 5 m
9	Mean chlorophyll-a, 0 – 50 m
10	Emergence from dormancy ANOVA
11	Dormancy duration is not related to deep water temperature during dormancy Dormancy duration is inversely related to surface temperature at onset
12	Conclusions No single observed environmental cue explains dormancy patterns Dormancy entry and emergence occur over a broad range of times, both among individuals and years
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14	Calanus IBM overview
15	Lipid accumulation window hypothesis: Decision to enter dormancy in stage CV is made in stage CIV. Criterion is attainment of 30% lipid content by weight
16	Model objective
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19	Next Steps Test LAW model against C. finmarchicus life cycle data sets in the NW Atlantic. Does the model reproduce variability in individual years? Test refined and alternative hypotheses - Additional conditions required? Examine mechanisms for emergence from dormancy: parameterization of metabolic limitation of diapause duration (Saumweber and Durbin, 2006) Examine influence of climate change scenarios on Calanus life cycle and population dynamics Further testing with time series observations, include measures of lipid levels in CIV and CV
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21	Individual-based model