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1

Subtidal2

Ocean Regions

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Oceanic Regions4

The region “A” is:

A. Shelf BreakB. Continental SlopeC. Continental Rise

A

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Figure 13.02a6

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7 8

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Subtidal Communities

• Soft-bottom• Rocky/hard-bottom

– Cold water reefs• calcareous algae, polychaetes, molluscs- cemented

together form stable 3-d environment

– Rocky bottoms• No desiccation, stable. In shallow areas dominated

by algae• Kelp forests

– Upper canopy, midwater, understory, nooks and crannies,

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Figure 13.2112 • Large 3-D habitat

• Large # of niches• Kelps provide main habitat, but

not necessarily the majority of the 1o production

• Many other algae in the understory

• Many animals live on the kelp

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Generalized Kelp Forest16

Urchin barrens

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Predator/Prey

Physical (temp)

18 What is the most important, direct predictor of Urchin overgrazing

A. High water tempB. Low nutrientsC. Low drift kelpD. Low Otter numbers

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Figure 13.2620

So. Cal. Kelp Forest

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Soft bottom Subtidal