Notes
Outline
Where Have the Fish Gone?
A Fresh Look at the Ocean
WHY Have the Fish Gone?
Marine Primary Production
…stable, rising or falling?
Production Declining?
Production Rising?
Can Fertility be Falling while “Greeness” is Rising in Coastal Waters?
Why Are Herbivores Disappearing While Their Food Supply Appears to Be Increasing?
Parallels between Coastal Ocean Trends (recorded) and those in Shoreline Organisms
Slide 9
Perennial Seaweeds: Better Direct Indicator Organisms for Ocean Fertility
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Fucus
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Rockweed – breakdown in sheltered locations
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If Seaweed Production Is Declining, How Is Phytoplankton Production Doing?
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Halifax Harbour
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What Is Increasing on Shoreline?
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Common themes in shore life and Fish Stocks
Cusk: Range Contraction
1973 - 2002
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Cod?
Slide 58
Northern Cod
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Contraction of Range of Haddock
Declining Growth of ESS Haddock
Turbot

…better
cold
tolerance

…more scope for contraction of northern range

…therefore a longer
lasting
fishery?
Size/age Decline of Mackerel
Overfishing  Vs   Declining Fertility
Differential Diagnosis
Fish size down
Abundance down
Fish condition better as abundance falls
Stock rebounds when fishing stopped
Fish size down
Abundance down
Fish in poor condition at low abundance
Declining size/age at maturity
Range contraction
Stock decline continues when fishing stopped
Mysteries in Fisheries Science
Slide 69
How Could Fishing Cause a Decline in Ocean Fertility?
Slide 71
Copepods
Decline in Bottom Water Nitrate Formation, 2001
C-fixation Data, Newfoundland
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