Globec Legacy- the SSC ideas

Philosophy

Body of Knowledge

Innovative Methodologies

Management and information transfer

Education/Outreach

Philosophy

Multi/interdisciplinary international collaboration

Coupled models as integrative tools

Mult-scale (time,space, institutional) analysis

Enhanced understanding of role of higher trophic levels

Innovative methodologies

Coupled models (trophic, scale, time) to investigate structure, function and variability

Sampling and technological advances

Retrospective studes of past ecosystem states

Comparative approach among regions

Management and information transfer

Policy (providing conceptual understanding of ecosystem function)

Managers (providing tools to incorporate climate-driven variability)

Communities (enhancing communication on global ecosystem change and marine sustainability

ESSAS: Ecosystem Studies of Subarctic Seas

A new GLOBEC program

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The rhomboid approach in GB GLOBEC

NPZ type

Copepod life cycle type

Larval fish dynamics type

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Copepod life history models: biological resolution on target species

Population dynamics of Calanus finmarchicus

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Examples of copepod models in Georges Bank GLOBEC

Miller, Lynch, Carlotti, Gentleman, Lewis, 1998

3-D finite element model and climatology

Individual based model

Growth and reproduction as f (temperature)

Supply to GB from all GoM basins and Scotian Shelf

Jordan and Georges must be restocked from upstream sources; role of local production in Wilkinson unresolved

Examples of copepod models in Georges Bank GLOBEC

Lynch, Gentleman, McGillicuddy, Davis, 1998

3D finite element hydrodynamic model, mean climatological circulation

Advective- diffusive-reactive equation, stage-based development

Food limitation represented as linear decline below 150 µgC l^-1

Surface only and depth-averaged transport

Base model has low mortality and abundant food

Spatial and temporal pattersn of Calanus recruitment in first generation consistent with observations only when model included food limitation of populations in low chlorophyll GoM in late winter/early spring

Examples of copepod models in Georges Bank GLOBEC

McGillicuddy, Lynch, Moore, Gentleman, Davis, Meise 1998

McGilluddy, Bucklin et al. papers

Adjoint data assimilation

3D finite element, climatological circulation

Assuming advective fields correct, calculate biological terms (R) that fit the observations

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Local Growth vs Retention/Exchange

Due to the circulation gyre, the residence time of water over the Bank is long relative to biological time scales so that in situ growth rather than lateral exchange is the dominant process controlling population abundance on the Bank

Fine-scale horizontal exchange causes significant leakage of nutrients, plankton and fish larvae across the frontal boundaries of the Bank, thus causing a chronic input and exchange/loss of nutrients, plankton and fish larvae

Secondary circulation associated with the tidal mixing fron causes a surface convergence near the well-mixed area boundary, providing a mechanism for concentrating target species in the tidal front zone. Transport towards the center of the Bank should be greatest for plankton in the upper layer of the water column in this zone, or for those species that undertake vertical migrations.

Periodic vertical migration of zooplankton and juvenile fish into and out of the sheared bottom-boundary layer can lead to horizontal movement against the mean flow

Stratification

Seasonal density stratification over the southern flank of the Bank causes prey aggregation in the pycnocline and increased survival of predator populations

Differences in phytoplankton abundance and species composition mediated by differences in water column stability result in measureable differences in copepod recruitment and growth rates. This leads to greater abundances in one region over another, due solely to high growth rates in situ

Turbulent mixing, generated by wind and tidal forcing, has a significant impact on rates of ingestion, respiration and predation; the processes of turbulent mixing and seasonal density stratification influence predator-prey encounter rates and thus growth and survival of individual organisms

Episodic gains and Exchanges/Losses

The residual mean flow is important in horizontal transport of zooplankton and fish larvae onto and off of Georges Bank, thus causing major sources and sinks for Bank populations

The seeding of copepod populations from the Gulf of Maine during winter has a significant impact on the level of prey biomass for larval fish during late spring and early summer. A corollary is that the population genetic makeup of the prey on Georges Bank reflects the generic makeup of the source populations

Storms, especially during winter and early spring, as well as impingement of warm-core rings, can cause large exchanges/losses of zooplankton and fish larvae from Georges Bank, thus increasing the apparent mortality rate of Bank populations

Population size is continuously regulated by incremental rather than episodic events, i.e. the time scale of the variability of the driving forces is of the same order as the generation time of the population.

Mortality

Predation rather than starvation is the dominant source of mortality of fish larvae; predation rather than advective exchange is ths dominant source of mortality of copepods

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	Philosophy
	Body of Knowledge
	Innovative Methodologies
	Management and information transfer
	Education/Outreach


	Multi/interdisciplinary international collaboration
	Coupled models as integrative tools
	Mult-scale (time,space, institutional) analysis
	Enhanced understanding of role of higher trophic levels


	Coupled models (trophic, scale, time) to investigate structure, function and variability
	Sampling and technological advances
	Retrospective studes of past ecosystem states
	Comparative approach among regions


	Policy (providing conceptual understanding of ecosystem function)
	Managers (providing tools to incorporate climate-driven variability)
	Communities (enhancing communication on global ecosystem change and marine sustainability


	Miller, Lynch, Carlotti, Gentleman, Lewis, 1998
		3-D finite element model and climatology
		Individual based model
		Growth and reproduction as f (temperature)
		Supply to GB from all GoM basins and Scotian Shelf
		Jordan and Georges must be restocked from upstream sources; role of local production in Wilkinson unresolved


	Lynch, Gentleman, McGillicuddy, Davis, 1998
		3D finite element hydrodynamic model, mean climatological circulation
		Advective- diffusive-reactive equation, stage-based development
		Food limitation represented as linear decline below 150 µgC l^-1
		Surface only and depth-averaged transport
		Base model has low mortality and abundant food
		Spatial and temporal pattersn of Calanus recruitment in first generation consistent with observations only when model included food limitation of populations in low chlorophyll GoM in late winter/early spring


	McGillicuddy, Lynch, Moore, Gentleman, Davis, Meise 1998
	McGilluddy, Bucklin et al. papers

		Adjoint data assimilation
		3D finite element, climatological circulation
		Assuming advective fields correct, calculate biological terms (R) that fit the observations


	Due to the circulation gyre, the residence time of water over the Bank is long relative to biological time scales so that in situ growth rather than lateral exchange is the dominant process controlling population abundance on the Bank
	Fine-scale horizontal exchange causes significant leakage of nutrients, plankton and fish larvae across the frontal boundaries of the Bank, thus causing a chronic input and exchange/loss of nutrients, plankton and fish larvae
	Secondary circulation associated with the tidal mixing fron causes a surface convergence near the well-mixed area boundary, providing a mechanism for concentrating target species in the tidal front zone. Transport towards the center of the Bank should be greatest for plankton in the upper layer of the water column in this zone, or for those species that undertake vertical migrations.
	Periodic vertical migration of zooplankton and juvenile fish into and out of the sheared bottom-boundary layer can lead to horizontal movement against the mean flow


	Seasonal density stratification over the southern flank of the Bank causes prey aggregation in the pycnocline and increased survival of predator populations

	Differences in phytoplankton abundance and species composition mediated by differences in water column stability result in measureable differences in copepod recruitment and growth rates. This leads to greater abundances in one region over another, due solely to high growth rates in situ

	Turbulent mixing, generated by wind and tidal forcing, has a significant impact on rates of ingestion, respiration and predation; the processes of turbulent mixing and seasonal density stratification influence predator-prey encounter rates and thus growth and survival of individual organisms


	The residual mean flow is important in horizontal transport of zooplankton and fish larvae onto and off of Georges Bank, thus causing major sources and sinks for Bank populations

	The seeding of copepod populations from the Gulf of Maine during winter has a significant impact on the level of prey biomass for larval fish during late spring and early summer. A corollary is that the population genetic makeup of the prey on Georges Bank reflects the generic makeup of the source populations

	Storms, especially during winter and early spring, as well as impingement of warm-core rings, can cause large exchanges/losses of zooplankton and fish larvae from Georges Bank, thus increasing the apparent mortality rate of Bank populations

	Population size is continuously regulated by incremental rather than episodic events, i.e. the time scale of the variability of the driving forces is of the same order as the generation time of the population.


	Predation rather than starvation is the dominant source of mortality of fish larvae; predation rather than advective exchange is ths dominant source of mortality of copepods