structure and function of marine ecosystems steven murawski ph.d. director, office of science &...
DESCRIPTION
Definitions An ecosystem is a geographically specified system of organisms (including humans), the environment, and the processes that control its dynamics. The environment is the biological, chemical, physical, and social conditions that surround organisms. When appropriate, the term environment should be qualified as biological, chemical, physical, and/or social. -3-TRANSCRIPT
Structure and Function of Marine Ecosystems
Steven Murawski Ph.D.Director, Office of Science & TechnologyNational Marine Fisheries Service
Challenges of Integrating Ecosystem Knowledge Definitions Key Processes in Marine Ecosystems Status of Ecosystem Science
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DefinitionsDefinitionsAn An ecosystemecosystem is a geographically specified system of organisms is a geographically specified system of organisms (including humans), the environment, and the processes that control its (including humans), the environment, and the processes that control its dynamics. dynamics.
The The environmentenvironment is the biological, chemical, physical, and social is the biological, chemical, physical, and social conditions that surround organisms.conditions that surround organisms.
When appropriate, the term When appropriate, the term environment should be environment should be qualified as biological, qualified as biological, chemical, physical, and/or chemical, physical, and/or social.social.
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Spatial Scales & Boundaries
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Phytoplankton
Zooplankton
Forage Fish
Piscivores
Apex Predators
Humans
The Trophic Pyramid and Energy Flow
1000 units
100 units
10 units
1 unit
0.1 unit
0.01 unit
If transfer efficiency is 10%-5-
Photosynthesis occurs primarily in waters less than 200 meters deep, which make up about 7% of the World’s Oceans
below 200 m, nutrients accumulate and must bebrought to the surface in order to support production- by upwelling & currents -6-
Scales and Observations
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Regional Climatology Affects Ecosystems
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Interactions Between Physical &Biological Components of Ecosystems
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Harvesting Affects Distributions & Abundances of Species
Atlantic cod
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Known
Unknown
Unknowable
Surface Production & Dynamics
Status of Major Species
Number of Species inthe Oceans
Structure of “pristine” ecosystems
3-D Structure of SelectedOcean Environments
Evolutionary effectsof human activitiesSynoptic Maps of the
Sea Floor
Food-web and particle size models
Valuing EcosystemGoods & Services
Climate Variation effects onspecies & ecosystems
Spatially-explicit models ofpredator-prey systems
Status of all “important” species
Mapping of Habitats
Predictive models ofmany-species interactions
NutrientEnrichment & Toxics
Reversibility ofHuman impacts