Primary Producers

Cyanobacteria

SILICOFLAGELLATES

Coccolithophore

Diatoms

Dinoflagellates

Foraminifera algae endosymbionts or kleptoplastic

“Plants”

Consumers

Copepod,Decapod, Pteropod, Heteropod,

Rocky Intertidal : best studied

Rocky Intertidal: Substrate: rocks, limited space, high energy, harsh Ranges highest tide to lowest tide margins 3-4 zones: supra, mid, infra littoral zones Species diversity and density increases from supra to infra Same genus do not overlap Species replacement and more species at lower latitudes Little coastal change but large seaward change (km vs m) Tropical rocky shores are more barren: do not be fooled

Intertidal Food Web

Succession

Mechanisms Stability-time hypothesis Disturbance Long stable condition allows the organisms to adjust via evolutionary change New species evolved to occupy vacant niche Disturbance Increase species diversity Keystone species

Balanus vs Chthalamus

Suboptimal Habitats Balanus vs Chthalamus Landward limit: physical factors (desiccation) Seaward limit: biological (predation) Absence of Chthalamus in the lower intertidal zone: predation, competition or both Conclusion: Chthalamaus are most abundant in a habitat that is not optimal for them

Rocky Intertidal Summary Physical space is in shortest supply Moderate disturbance by predator prevent dominant species from taking over Some were forced to live at sites that are less optimal Manipulation of a few key species can switch from one persistent steady state to a different stable condition

FOOD SECURITY