Kelp Forest Ecology
Marine Habitats
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•Kelp forest distribution
•Macrophytes
•Vertical zonation
•Space competition
•Grazers: role they play
•Predation on grazers
•Sea Otters
•Factors affecting algal populations
•Threats to Kelp Forests
Estuaries
Sea Grass
Mangroves
Coral reefs
Kelp Forests
Polar seas
The deep sea
Kelp forests have a limited distribution
dependent on
Laminariales
•Substrate: hard
•temperature/nutrients
•water depth
•exposure (waves)
Pelagophycus
Lives deeper
no canopy
Nereocystis:
bull kelp
One pneumatocyst
withstands great wave stress
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Macrocystis
Vertical zonation: understory
•Major canopy former
•Zonation in a kelp forest
•Grows from a meristem
•Perennial
Vertical Structure: turf
Grazers: Mitra
Space competition
Grazers: Calliostoma
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Grazers: urchins
Predators: Kelletia
Key grazers
•Urchins
•Abalone
•Tegula
•other molluscs
•??
Key predators
•Sea Otters
•Molluscs
•Rockfish
•??
Grazers: tegula (snails)
Predators: Sea Otters
Sea Otters and Sea Urchins:
a kelp forest paradigm
Sea Urchins eat kelp, especially new recruits
If kept in check, they eat drift kelp
If populations expand, they will eat established kelp
Sea Otters eat urchins, especially exposed ones
They will keep sea urchin populations in check
The Aleutian Island studies
Sea Otters as a keystone predator
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Threats to kelp Forests:
Other factors affecting kelp forests
(algal populations)
Kelp Harvesting
Waves/storms
Harvesting?
Nearshore fishing
•To 3 feet underwater
•Fish and Game regulated
•‘self regulation’
•Seasons
•Effects on kelp plant and
kelp forest ecology
Rockfish play an important ecological role in Kelp Forests
•Live fish fishery
•Long linelining
•Power-plants: warm water
effluent, water intake: point source
pollution
•Sewage: high nutrients
•Agricultural runoff (non-point
source pollution)
•Construction
•Sedimentation/scour
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