Kelp Forest ZonationInshore(Z1)Kelp Canopy(Z2)Offshore(Z3)CanopyUnderstoryAlgal Turf
MacrocystisLaminariaEgregiaNereocystisPhyllospadix
A. Canopy Assemblages (isopods, tubeworms, hydrozoans and bryozoans)B. Planktonic Assemblages (jellyfish, fish larvae, diatoms, and crustaceans).C. Holdfast Assemblages (sea urchins, crustaceans, brittle stars, and sea anemones)D. Horizontal Substrate Assemblages (urchins, sea stars, algae, tunicates, and bottom fish).E. Vertical Wall Assemblages (coralline algae, anemones, cup corals, sponges, and bryozoans)
Holdfast CommunityPlanktonCanopy
Vertical WallHorizontal Surface
OrcaSea OtterKelpUrchinsEcological Relationships in Kelp Forests
Ecological Relationships in Kelp Forests - Aleutian ArchipelagoAdak Island
Ecological Relationships in Kelp Forests - Aleutian Archipelago19721997Otter #
Ecological Relationships in Kelp Forests - Aleutian Archipelago19721997Otter #Urchin Biomass
Ecological Relationships in Kelp Forests - Aleutian Archipelago19721997Otter #Urchin BiomassGrazing Intensity
Ecological Relationships in Kelp Forests - Aleutian Archipelago19721997Otter #Urchin BiomassGrazing IntensityKelp Density
Mortality of Kelp - Effect of El Nio event Recovery of community (Ebeling et al., 1985)Destroyed kelp (Macrocystis) canopy but left understory kelpOriginal situation - Macrocystis canopy, understory kelp (Pterygophora)- urchins S. purpuratus & S. franciscanus feed in crevices on drift kelpReduction in drift kelp used by urchinsUrchins forage in open on understory kelpUrchins destroy remaining kelpStorm 1Storm 2Kills urchins and left bare rockKelp settlement and mature forest (1 year)
Mortality of Kelp - Effect of El Nio event Other El Nio Effects-rip up holdfasts no vegetative growth-high water temperature retards growth-reduction in nitrogen retards growth
General Model for Maintenance of Barrens and Kelp areasBARRENSHigh grazing activityLow algal recruitmentSevere stormsLow nutrientWarm temperaturesLow driftabundanceLow standing stock of attached algaeLow grazing activityHigh algal recruitmentBenign stormsHigh nutrientLow temperaturesHigh driftabundanceHigh standing stock of attached algaeKELPSTABLE STATES
General Model for Maintenance of Barrens and Kelp areasHarold & Reed, 1985Barren Ground-little drift kelp- created by urchin grazing- urchins actively forageKelp Forest-abundant drift kelp- urchins remain in crevicesRecruitment of kelpEffect of urchins due to a change in behaviour not numbers
General Model for Maintenance of Barrens and Kelp areasHarold & Reed, 1985Effect of urchins due to a change in behaviour not numbers
General Model for Maintenance of Barrens and Kelp areasHarold & Reed, 1985
Kelp and other algaeSea urchinsSea starsSea otterSmall herbivorous fish & invertebratesDrift algae & dead animalsAbaloneSharksPlanktonic algaePlanktonic invertebratesSessile invertebratesSmaller predatoryFish and invertebratesLarger crabsLarger fish & octopusKelp Forest Food Web (with otters)
Kelp and other algaeSea urchinsSea starsSea otterSmall herbivorous fish & invertebratesDrift algae & dead animalsAbaloneSharksPlanktonic algaePlanktonic invertebratesSessile invertebratesSmaller predatoryFish and invertebratesLarger crabsLarger fish & octopusKelp Forest Food Web (without otters)
Kelp Forest ProductivityTropical Rain ForestTropical Seasonal ForestEvergreen ForestDeciduous ForestKelp ForestBoreal Forest3.0
2.5
2.0
1.5
1.0
0.5
050
40
30
20
10
0Producer BiomassKg/m2Annual Net ProductionKg/m2/yrLitter MassKg/m2/yr
Kelp Forest ProductivitySUSPENSION FEEDERSMusselSoft coralBarnacleSea AnemoneRock JingleMysid
DETRITIVORESAmphipodCrab
PREDATORSRock greenlingSea starCormorant0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100Percent of Kelp Derived Carbon
Next timeCoral Reefs
************
