SeaOtter2 [Compatibility Mode]

SeaOtter2 [Compatibility Mode] - Sea otter The Sea Otter...

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Unformatted text preview: Sea otter The Sea Otter family Mustelidae Order Carnivora Pages 42- 45 42- Enhydra lutris Fur is water proof, but requires constant care No fat or blubber for insulation High metabolic rate (4.4-5.6 x human) 4.4 Females mature at 3-4 yrs, males at 3 yr 3 Gestation 8-9 mo, pups dependent 10-12 mo 810 Predators: white sharks, bald eagles, & killer whales (maybe increasing due to Steller’s sealion decline) Keystone species: maintain kelp community Their Fur is their salvation and nearly their downfall In 1741, 100,000 to 150,000 sea otters distributed from Baja California around to Kamchatka Island About 1,000,000 pelts harvested by 1911 pelts harvested by 1911 Only 1-2,000 remained at moratorium 1 California population thought to be extinct until 50 individuals discovered in 1935 Pelage is composed of guard hairs and dense under fur (1:60 or 80) Status: declining in California and N Pac 1 Simple LOOP model (1, 0, -1) Community matrix (direct effects) -1 -1 A := -1 0 0 1 -1 0 -1 0 1 0 -1 0 1 1 1 1 -1 1 0 0 -1 0 -1 1: Sea Otter, 2: Urchin, 3: Other Prey, 4: Kelp Forest, 5: Kelp Community Feedback loops result in indirect effects (- or +) (- LOOP Model Output: net # of feedback loops 4 -2 adjoint_A -2 2 0 0 3 0 -3 -3 2 -1 2 1 3 4 1 -2 5 3 -2 1 -2 -1 3 1: Sea Otter, 2: Urchin, 3: Other Prey, 4: Kelp Forest, 5: Kelp Community Model Output: direct & indirect effects of changing urchin abundance Increase Urchins Sea Otter Urchins Other Prey Kelp Forest Kelp Fishes Decrease Urchins Model Output: direct & indirect effects of increasing urchin abundance and reducing sea otters Increase Urchins Decrease Otters Sea Otter Urchins Other Prey Kelp Forest Kelp Fishes Net effect 0 3 0 -3 -3 0 -3 0 3 3 0 3 0 -3 -3 + + + + + -4 2 2 -2 0 = = = = = -4 5 2 -5 -3 2 ...
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