Food Webs in the Wake of Atlantic cod Present is not the key to the pastPresent is not the key to...
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Food Webs in the Food Webs in the Wake of Atlantic cod Wake of Atlantic cod • Present is Present is not the key not the key to the past to the past • How might How might coastal coastal ecosystems ecosystems have have changed changed since cod since cod extirpation extirpation
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Transcript of Food Webs in the Wake of Atlantic cod Present is not the key to the pastPresent is not the key to...
Food Webs in the Food Webs in the Wake of Atlantic codWake of Atlantic cod
• Present is not Present is not the key to the the key to the pastpast
• How might How might coastal coastal ecosystems have ecosystems have changed since changed since cod extirpationcod extirpation
What’s known and What’s known and knowable about knowable about Atlantic cod? Atlantic cod?
• They were big predatorsThey were big predators
• Had broad trophic latitudeHad broad trophic latitude
• Were abundantWere abundant
• Lived in coastal benthic habitatsLived in coastal benthic habitats
• Strong interactors (controlled the Strong interactors (controlled the structure of food webs)structure of food webs)
Monhegan I., Maine1880s
Knowable?(integrate ecological processes
with historical patterns)
Cod vertebra: 4,100 y bp
Fish hooks: 5,000 y bp
Cod Tomcod Sculpin Flounder Sturgeon ? Large ? Small Other0
20
40
60
80
100
Fish Species
% B
one
Wei
ght
Fish bones in Indian “kitchen” middens500 - 2,500 years ago
Carlson 1986
Archaeological site inBoothbay Harbor, Maine
Coast of Maine
The Turner Farm
Penobscot Bay
Spies & Lewis 2001
400 - 4500 ybp
Atlantic codFlounder total
Sea minkFish unidentifiedWinter flounderSoftshell clams
SwordfishSculpin
SturgeonYellowtail flounder
TomcodHarbor seal
Seal (unidentified)Grey seal
American dabDogfishCunne
rHerringBlue mussel
HaddockHalibutPollock
wolf fishSand flounder
SalmonidsAmerican Eel
Sea urchinHarp Seal
AlewifeWaved whelk
QuahodCarchardon (great white)
Plocaena (porpoise)Cus
kBalaena ( Right)MackerelBluefish
0 10 20 30 40
Average percent fragments from all strata
Atlantic codFlounder total
Sea MinkFish spp
Winter flounderSoftshell clams
SwordfishSculpin
SturgeonYellowtail flounder
TomcodHarbor seal
Phocid unidentifiedGrey seal
American dabDogfishCunnerHerring
Blue musselHaddock
HalibutPollock
wolf fishSand flounder
Salmonid American eel
Sea urchinHarp Seal
AlewifeWaved whelk
QuahodGreat white shark
PorpoiseCusk
Right whaleMackerelBluefish
4350 4100 3550 1600 400
Proportion of Bone Mass
Years bp
Atlantic codFlounder total
Sea MinkFish spp
Winter flounderSoftshell clams
SwordfishSculpin
SturgeonYellowtail flounder
TomcodHarbor seal
Phocid unidentifiedGrey seal
American dabDogfishCunnerHerring
Blue musselHaddock
HalibutPollock
wolf fishSand flounder
Salmonid American eel
Sea urchinHarp Seal
AlewifeWaved whelk
QuahodGreat white shark
PorpoiseCusk
Right whaleMackerelBluefish
4350 4100 3550 1600 400
Proportion of Bone Mass
Years bp
No lobster or crabs?
0500100015002000250030003500400045000
20
40
60
80
100
120
Years Before Present
Atl
anti
c co
d bo
dy le
ngth
(cm
)Cod Size Over Past 4500 years
5000
Fishing Grounds of Coastal Maine 1830 - 1880 (Goode 1887)
Acadia National Park
Turner Farm Site
0 10 20 30 40
NereidiformiaOther Polychaeta
AmphipodaEuphausiacea
PandalidaeCrangonidae
AxiidaePaguridaeMajidae
CancridaeOther Decapoda
Other CrustaceaGastropoda
BivalviaCephalopoda
Other molluscaEchinoidea
OphiuroideaOther Echinodermata
ClupeidaeGadidae
ScombridaeScorpaenidaeOther Pisces
Other groupsAnimal remains
Sand and rock
% Prey
Langton & Bowman 1980
Crustaceans
Fish
Sand and rocks!
Cod’s Prey
Echinoderms
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40 cm
