A preliminary comparison of the trophic structure of some large marine ecosystems

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A preliminary comparison of the trophic structure
of some large marine ecosystems

• Rainer Froese, IfM
• Uwe Piatkowski, IfM
• Stefan Garthe, FTZ
• Daniel Pauly, UBC

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Overview

• Need to Understand Marine Ecosystems
• Available data species composition, trophic
  level of species
• Approach compare trophic signatures between
  groups of organisms and between ecosystems

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Hypotheses

• Hypothesis I A given taxonomic group will have
  similar signatures in similar ecosystems
• Hypothesis II Different taxonomic groups will
  have different signatures

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Number of Marine Fish Species by Trophic Level
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Trophic Signatures of Fish Species Tropical LMEs
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Trophic Signatures of Fish Species Tropical and
Temperate, Brackish LMEs
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Trophic Signatures of Fishes in Five LMEs
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Mean Max Length of Fishes by Trophic Level
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Trophic Structure of Fish, Birds, Cephalopods and
Marine Mammals in the North Sea
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Trophic Pyramid by Species Numbers for the North
Sea
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Conclusions

• Species Composition of Ecosystems and Trophic
  Signatures are Long-term Characters
• Trophic Signatures Can be Used to Classify Groups
  of Organisms and LMEs
• Strong Separation between Vertebrates and
  Invertebrates at Troph 3
• Finer Resolution Needed for Lower Levels

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Thank You

• We thank the FishBase team for encoding much of
  the data used in this study and for programming
  the various tools (TrophLab, Trophic Pyramids).
• Data and tools are available at
• www.fishbase.org