fisheries - librettoquiz+#4+note... · 10/21/2009 1 chapter 8: food webs and marine fisheries food...
TRANSCRIPT
10/21/2009
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Chapter 8: Food Webs
and Marine Fisheries Food Webs
Fish Gotta Eat
PhytoplanktonFocus on Diatoms – producers in the ocean
Zooplankton
Focus on Copepods
Small Predators
KrillImmature versions of larger animals
Small Fish: Sardines, Menhaden and Herring
Top Predators
1. Jelly Fish
Top Predators
2. Cephalopods
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Top Predators
3. Large Fish: Sharks, Tuna, Mackerel
Top Predators
4. Marine Mammals: Seals, Walruses, Dolphins, Whales
Food Chains and Food WebsBig fish eat little fish; that’s how the food cycle works. Of course, there’s more to it
than that. A whirlwind spiral up the marine food chain goes like this:
Phytoplankton—microscopic plants drifting in the water—feed the copepods and
other grazers that feed the small menhaden and crustaceans that feed the stripers
and bluefish that feed the tunas and swordfish that feed us.
From The Marine Food Web by Tony Corey and David Beutel
Overfishing Changes Food Webs
“Fishing Down” Food Webs
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A Historical Decline in “Trophy Fish”
Photographs showing trophy fish caught on
Key West charter boats a) 1957, b) early 1980s,
and c) 2007.
From Scripps Institution of Oceanography.
Historical Photographs Expose Decline in
Florida's Reef Fish, New Scripps Study Finds.
PhytoplanktonFocus on Diatoms – producers in the ocean
Diatoms
• Originated during the Jurassic (184 mya)
• Reproduce sexually and asexually
• Food source for shellfish
• “glass” skeletons which produce fossils
Two types of Diatoms
1. Centric = radialy symmetrical
2. Pennate = bilaterally symmetrical
Uses of Diatoms
1. Good for filtration – tiny size
2. Insecticide – sharp edges cut through the
covering of insects
3. Fire resistance
4. Many others
Chapter 9:
Food Webs
Microbial Food Webs
It’s the little details that count
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The Microbial Food Web (We Think) Maybe it looks like this ?
Members of the Microbial Food Web
1. Viruses
Members of the Microbial Food Web
2. Bacteria
A. Cyanobacteria
Members of the Microbial Food Web
2. Bacteria
B. Vibrio Bacteria
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Members of the Microbial Food Web
3. Archea
Members of the Microbial Food Web
4. Chromalveolata
A. Dinoflagellates
Members of the Microbial Food Web
4. Chromalveolata
B. Coccolithophores
Members of the Microbial Food Web
4. Chromalveolata
C. Diatoms
Members of the Microbial Food Web
4. Chromalveolata
D. Cilliates