diet and predators of intertidal animals?

can you tell me the diet and predators of these animals who live on the intertidal? or a website where i can find the answers
Diet/Predators
periwinkle snails:
dog whelk:
barnacles:
intertidal crab:
intertidal octopus:
sea anemone:
sea urchin:
plankton:
chiton:
limpet:
sea hare:
sea star:
seagull:

thanks a lot!!!