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Discussion group 1aWhat are the key basin scale hypotheses ???
• Do we need to connect trophic levels, from autotrophs to heterotrophs in order to understand basin scale variability?
• What organisms?
• How many species must be included as target organisms?
• Draw a food web, life history chart.
• How do we include fish?
• What are the key processes linking variability in zooplankton and fish?
• What are the links between the ocean and the shelf?
• Can we use or recommend long-term observation or modelling?
• Can we make long-range predictions of target organisms?
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Discussion group 1a
• What are the key basin scale hypotheses that we are interested in?
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Discussion group 1aHypothesis x
• What species and trophic levels are involved?
• What geographical/oceanographic domains are involved?
• Draw the relevant food web/life history chart…
• What are the key processes linking the species/trophic levels?
• What are the key processes linking spatial domains
• What are the key processes influencing target species demography?
• What observations do we need?
• What chance is there of making long-range predictions?
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Discussion group 1a
• What are the key basin scale hypotheses that we are interested in?
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Discussion group 1aHypothesis 2
• What species and trophic levels are involved?
• What geographical/oceanographic domains are involved?
• Draw the relevant food web/life history chart…
• What are the key processes linking the species/trophic levels?
• What are the key processes linking spatial domains
• What are the key processes influencing target species demography?
• What observations do we need?
• What chance is there of making long-range predictions?
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Hypotheses….
• How interconnected are the regions around the Atlantic rim?
• Pan-Atlantic species with strong exchange between regions – Calanus – metapopulation or panmictic?
• Pan-Atlantic species with weak exchange between regions, but nevertheless coherent aspects of dynamics – regional stocks with basin scale forcing (cod)
• Basin scale data/models as boundary conditions for regional models
• Basin scale changes in plankton diversity• Changes in regional productivity – top down vs bottom
up? – needs basin scale understanding as background
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Discussion group 1aHypothesis 1 Changes in regional productivity – top down vs bottom up?
• What species and trophic levels are involved?
• What geographical/oceanographic domains are involved?
• Draw the relevant food web/life history chart…
• What are the key processes linking the species/trophic levels?
• What are the key processes linking spatial domains
• What are the key processes influencing target species demography?
• What observations do we need?
• What chance is there of making long-range predictions?
• Primary mesozoop and euphausids., lesser detail on micro/phyto, how to represent losses of mesozoo
• - link to local models of planktivorous fish – eg. capelin
• Mesozoo directly linked to basin scale- fish more regional.• NA is good place to test whether basin scale necessary
• Target species Calanus/pseudocal/euphausids/planktivorous fish (redfish/herring/sprat/blue whiting/sandlance/capelin/Norway pout).
• Calanus – metapopulatins linked by deep and surface circulation
• Pseudocalanus – food production ?• Predation
• Western Atlantic equivalent of OWSM/OWSI (deep water) (automated measurements from buoys)
• Information on microzooplankton biomass.• Data assimilation for generation of gridded time series of
biological state variables.
• Scenario forecasts are possible
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Relationships between surface and deep populations
Overwinter deeppopulation
Summer surfacepopulation
Terminallineage
Terminallineage
Springascent
Springascent
Autumndescent
Heath et al. 2004Backhaus (1994) hypothesis revisited
Reproductionand lipid accumulation
Reproductionand lipid accumulation
Diapause
Diapause